gnuplot 6.0
An Interactive Plotting Program
Thomas Williams & Colin Kelley
Version 6.0 organized by: Ethan A Merritt and many others
Major contributors (alphabetic order):Christoph Bersch, Hans-Bernhard Bröker,
John Campbell, Robert Cunningham,
David Denholm, Gershon Elber,
Roger Fearick, Carsten Grammes,
Lucas Hart, Lars Hecking, Péter Juhász,
Thomas Koenig, David Kotz, Ed Kubaitis,
Russell Lang, Timothée Lecomte,
Alexander Lehmann, Jérôme Lodewyck,
Alexander Mai, Bastian Märkisch, Tatsuro Matsuoka,
Ethan A Merritt, Petr Mikulı́k, Hiroki Motoyoshi,
Daniel Sebald, Carsten Steger, Shigeharu Takeno,
Tom Tkacik, Jos Van der Woude,
James R. Van Zandt, Alex Woo, Johannes Zellner
Copyright © 1986 - 1993, 1998, 2004 Thomas Williams, Colin Kelley
Copyright © 2004 - 2023 various authors
Mailing list for comments: gnuplot-info@lists.sourceforge.net
Web site and issue trackers: http://sourceforge.net/projects/gnuplot

This manual was originally prepared by Dick Crawford.
Version 6.0 (December 2023)

2

gnuplot 6.0

CONTENTS

Contents
I

Gnuplot

22

Copyright

22

Introduction

22

Seeking-assistance / Bugs

23

New features in version 6

24Function blocks and scoped variables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

24

Special and complex-valued functions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

24

New plot styles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

25

Hulls, masks, and smoothing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

25

Named palettes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

26

New data formats. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

26

New built-in functions and array operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

26

Program control flow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

27

Multiplots . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

27

New terminals and terminal options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

27

Watchpoints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

28

Week-date time support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

28

Other new features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

28

Brief summary of features introduced in version 5 . . . . . . . . . . . . . . . . . . . . . . . . . . . .

29

Features introduced in 5.4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

29

Features introduced in 5.2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

29

Features introduced in 5.0 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

30

Differences between versions 5 and 6

30

Plot style details . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

30

Deprecated syntax . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

30

Demos and Online Examples

31

Batch/Interactive Operation

31

Command line options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

31

Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

32

Canvas size

32

Command-line-editing

32

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gnuplot 6.0

3

Comments

33

Coordinates

33

Datastrings

34

Enhanced text mode

34

Escape sequences . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

35

Environment

36

Expressions

36

Complex values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

37

Constants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

38

Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

39

Integer conversion functions (int floor ceil round) . . . . . . . . . . . . . . . . . . . . . . . . .

42

Elliptic integrals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

42Complex Airy functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

43Complex Bessel functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

43

Expint . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

43Fresnel integrals FresnelC(x) and FresnelS(x) . . . . . . . . . . . . . . . . . . . . . . . . . . .

43Gamma . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

44

Igamma . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

44

Invigamma . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

44

Ibeta . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

44

Invibeta . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

44

LambertW . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

44

LnGamma . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

45

Random number generator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

45

Special functions with complex arguments . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

45

Synchrotron function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

45Time functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

45Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

45

Timecolumn. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

46

Tm structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

46

Tm week . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

46

Weekdate iso . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

46

Weekdate cdc . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

47

Uigamma . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

47

Using specifier functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

47

Column . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

47

Columnhead . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

47

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CONTENTS

Stringcolumn . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

47

Valid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

47

Value . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

48

Counting and extracting words . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

48

Zeta . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

49

Operators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

49

Unary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

49

Binary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

49

Ternary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

50

Summation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

51

Gnuplot-defined variables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

51

User-defined variables and functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

52

Arrays . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

52

Array functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

53

Array indexing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

53

Fonts

54

Cairo (pdfcairo, pngcairo, epscairo, wxt terminals) . . . . . . . . . . . . . . . . . . . . . . . . . . .

54

Gd (png, gif, jpeg, sixel terminals) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

54

Postscript (also encapsulated postscript *.eps)

54. . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Glossary

55

Inline data and datablocks

55

Iteration

56

Linetypes, colors, and styles

56

Colorspec . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

57

Background color . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

58

Linecolor variable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

58

Palette . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

58

Rgbcolor variable. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

59

Dashtype . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

59

Linestyles vs linetypes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

60

Special linetypes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

60

Layers60

Mouse input

61

Bind . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

61

Bind space . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

62

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Mouse variables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

62

Persist63

Plotting

63

Plugins

63

Scope of variables

64

Start-up (initialization)

64

String constants, string variables, and string functions

65

Substrings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

65String operators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

65String functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

65String encoding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

66

Substitution and Command line macros

66

Substitution of system commands in backquotes . . . . . . . . . . . . . . . . . . . . . . . . . . . .

66

Substitution of string variables as macros . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

66

String variables, macros, and command line substitution . . . . . . . . . . . . . . . . . . . . . . . .

67

Syntax
Quote marks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

67
68

Time/Date data

68

Watchpoints

69

II

Watch mouse . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

70

Watch labels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

70

Plotting styles

ArrowsArrowstyle variable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

71
71
71

Bee swarm plots

72

Boxerrorbars

72

Boxes

72

2D boxes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

73

3D boxes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

73

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Boxplot

74

Boxxyerror

75

Candlesticks

75

Circles

76

Contourfill

77

Dots

77

Ellipses

78

Filledcurves

78

Fill properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

79

Financebars

79

Fillsteps

80

Fsteps80

Histeps80

Heatmaps

81

Histograms

82

Newhistogram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

84

Automated iteration over multiple columns . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

85

Histogram color assignments

85. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Image

85

Transparency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

86

Image pixels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

86Impulses

87

Labels

87

Lines

88

Linespoints

88

Masking89

Parallelaxes

89

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Polar plots

90

Points90

Variable point properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

90Polygons

91

Rgbalpha

91

Rgbimage

92

Sectors

93

Spiderplot

93

Newspiderplot . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

94

Steps

94

Surface

94

Vectors

95

Xerrorbars

96

Xyerrorbars

96

Xerrorlines

97

Xyerrorlines

97

Yerrorbars

97

Yerrorlines

98

3D plots

99

Surface plots . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

99

2D projection (set view map) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

99

PM3D plots . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

99

Fence plots

100

Isosurface

100

Zerrorfill

100

Animation101

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Commands

CONTENTS

102

Break

102

Cd

102

Call

102

ARGV[ ] . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103
Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103
Clear

103

Continue

104

Do

104

Evaluate

104

Exit

105

Fit

105
Adjustable parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107
Short introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108
Error estimates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108
Statistical overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109
Practical guidelines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109
Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110
Error recovery. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111

Multi-branch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111
Starting values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111
Time data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112
Tips . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112
Function blocks

114

Help

116

History

116

If

116

For

117

Import

117

Load

117

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Local

118

Lower

118

Pause

119

Pause mouse close . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119
Pseudo-mousing during pause . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120
Plot

120

Axes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120
Binary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121
General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121
Array . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122
Record . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122
Skip . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122
Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122
Endian . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122
Filetype . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123
Avs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123
Edf. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123

Png . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123
Keywords . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123
Scan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123
Transpose . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123
Dx, dy, dz . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124
Flipx, flipy, flipz . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124
Origin. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124

Center . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124
Rotate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124
Perpendicular . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124
Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124
Columnheaders . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126
Csv files . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126
Every . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126
Example datafile . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127
Filters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 128
Bins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 128
Convexhull . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 128
Concavehull . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129
Mask. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 130

Sharpen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 130

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Zsort . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 130
Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 130
Skip . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 131
Smooth . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 131
Acsplines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 132
Bezier . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 132
Bins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 132
Csplines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 132
Mcsplines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 132
Path . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 132
Sbezier . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133
Unique. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133

Unwrap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133
Frequency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133
Fnormal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133
Cumulative . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133
Cnormal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133
Kdensity. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 134

Special-filenames . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 134
Piped-data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135
Using . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135
Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 136
Using examples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 136
Pseudocolumns . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 137
Arrays . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 137
Key . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 138
Xticlabels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 138
X2ticlabels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 138
Yticlabels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 138
Y2ticlabels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 138
Zticlabels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 138
Volatile . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 138
Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 138
Parametric . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 139
Ranges . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 139
Sampling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 140
1D sampling (x or t axis) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 140
2D sampling (u and v axes) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141
For loops in plot command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141
Title . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 142

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11With . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 143
Print

145

Printerr

146

Pwd

146

Quit

146

Raise

146

Refresh146

Remultiplot

147

Replot147

Reread

147

Reset

147

Return

148

Save

148

Set-show149

Angles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 149
Arrow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 150
Autoscale . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 151
Noextend . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 152
Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 152
Polar mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 152
Bind . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 152
Bmargin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 152
Border . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153
Boxwidth . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 154
Boxdepth . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 154
Chi shapes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 155
Color. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 155

Colormap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 155
Colorsequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 155
Clabel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 156
Clip . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 156
Cntrlabel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 156

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Cntrparam . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157
Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 158
Color box . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 159
Colornames . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 160
Contour . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 160
Cornerpoles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 161
Contourfill . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 161
Dashtype . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 161
Datafile . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 161
Set datafile columnheaders . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 161
Set datafile fortran . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 162
Set datafile nofpe trap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 162
Set datafile missing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 162
Set datafile separator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 162
Set datafile commentschars . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 163
Set datafile binary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 163
Decimalsign . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 163
Dgrid3d . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 164
Dummy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 165
Encoding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 166
Errorbars . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 166
Fit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 167
Fontpath . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 168
Format. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 168

Gprintf . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 169
Format specifiers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 169
Time/date specifiers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 170
Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 171
Grid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 171
Hidden3d . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 172
History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 173
Isosamples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 174
Isosurface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 174
Isotropic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 174
Jitter. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 175

Key . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 175
3D key . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 176
Key examples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 176
Extra key entries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 177
Key autotitle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 177

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13

Key layout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 177
Key placement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 178
Key offset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 179
Key samples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 179
Multiple keys . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 179
Label . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 180
Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 181
Hypertext . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 182
Linetype . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 182
Link . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 183
Lmargin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 183
Loadpath . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 184
Locale . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 184
Logscale . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 184
Macros . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 185
Mapping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 185
Margin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 185
Micro . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 186
Minussign . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 186
Monochrome . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 186
Mouse . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 187
Doubleclick . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 188
Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 188
Mouseformat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 188
Scrolling. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 188

Zoom . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 189
Mttics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 189
Multiplot . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 189
Mx2tics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 191
Mxtics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 191
Mxtics time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 192
My2tics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 192
Mytics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 192
Mztics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 192
Nonlinear . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 192
Object . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 193
Rectangle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 194
Ellipse . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 195
Circle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 195
Polygon . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 195

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Depthorder . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 196
Offsets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 196
Origin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 196
Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 197
Overflow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 197
Float . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 197
NaN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 198
Undefined . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 198
Affected operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 198
Palette . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 198
Rgbformulae . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 199
Defined . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 199
Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 200
Gray . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 201
Cubehelix . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 201
Viridis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 201
Colormap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 201
File . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 201
Gamma correction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 202
Maxcolors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 202
Color model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 202
Postscript . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 203
Parametric . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 203
Paxis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 203
Pixmap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 204
Pixmap from colormap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 204
Pm3d . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 205
With pm3d (pm3d explicit) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 205
Pm3d implicit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 206
Algorithm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 206
Lighting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 207
Position . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 207
Scanorder . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 208
Clipping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 208
Color assignment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 208
Corners2color . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 209
Border . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 209
Fillcolor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 209
Interpolate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 209
Deprecated options. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 210

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Pointintervalbox . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 210
Pointsize . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 210
Polar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 210
Polar grid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 211
Print . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 212
Psdir . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 212
Raxis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 212
Rgbmax . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 212
Rlabel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 212
Rmargin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 212
Rrange . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 213
Rtics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 213
Samples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 213
Size . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 213
Spiderplot . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 214
Style . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 214
Set style arrow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 215
Boxplot . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 216
Set style data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 217
Set style fill . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 217
Set style fill border . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 217
Set style fill transparent . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 218
Set style function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 218
Set style histogram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 218
Set style increment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 218
Set style line . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 218
Set style circle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 220
Set style rectangle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 220
Set style ellipse . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 220
Set style parallelaxis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 221
Set style spiderplot . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 221
Set style textbox . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 221
Set style watchpoint . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 221
Surface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 222
Table. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 222
Plot with table . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 223

Terminal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 223
Termoption . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 224
Theta . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 224
Tics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 224

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Ticslevel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 225
Ticscale . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 225
Timestamp . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 225
Timefmt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 225
Title . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 226
Tmargin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 227
Trange . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 227
Ttics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 227
Urange . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 227
Version . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 228
Vgrid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 228
View . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 228
Azimuth. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 229

Equal axes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 229
Projection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 229
Vrange . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 229
Vxrange . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 229
Vyrange . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 230
Vzrange . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 230
Walls. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 230

Watchpoints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 230
X2data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 231

X2dtics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 231
X2label . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 231
X2mtics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 231
X2range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 231
X2tics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 231
X2zeroaxis. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 231

Xdata . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 231
Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 232
Xdtics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 232
Xlabel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 232
Xmtics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 233
Xrange . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 233
Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 234
Extend . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 235
Xtics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 235
Xtics series . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 236
Xtics list . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 237
Xtics timedata . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 238

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Geographic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 238
Xtics logscale . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 239
Xtics rangelimited . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 239
Xyplane . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 239
Xzeroaxis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 240
Y2data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 240

Y2dtics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 240
Y2label . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 240
Y2mtics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 240
Y2range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 240
Y2tics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 240
Y2zeroaxis. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 240

Ydata . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 240
Ydtics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 240
Ylabel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 241
Ymtics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 241
Yrange . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 241
Ytics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 241
Yzeroaxis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 241
Zdata . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 241
Zdtics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 241
Zzeroaxis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 241
Cbdata . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 241
Cbdtics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 241
Zero . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 242
Zeroaxis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 242
Zlabel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 242
Zmtics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 242
Zrange . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 242
Ztics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 242
Cblabel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 243
Cbmtics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 243
Cbrange . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 243
Cbtics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 243
Shell

243

Show

243

Show colornames . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 244
Show functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 244
Show palette . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 244

18gnuplot 6.0

CONTENTSShow palette gradient . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 244
Show palette palette . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 244
Show palette rgbformulae . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 245
Show plot . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 245
Show variables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 245
Splot

245

Data-file . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 246
Matrix. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 246
Uniform matrix . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 247
Nonuniform matrix . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 247
Sparse matrix . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 248
Every . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 248
Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 248

Example datafile . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 249
Grid data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 249
Splot surfaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 250
Voxel-grid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 250
Stats (Statistical Summary)251

Name . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 252
Test for existence of a file . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 252
Voxelgrid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 253
System

253

Test

253

Toggle253

Undefine

254

Unset

254

Linetype . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 254
Monochrome . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 254
Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 254
Terminal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 254
Warnings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 255
Update255

Vclear

255

Vfill

255

CONTENTS

gnuplot 6.0

19

Warn

256

While

256

IV

257

Terminal types

Complete list of terminals

257

Aifm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 257
Aqua . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 257
Be . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 257
Command-line options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 258
Monochrome options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 258
Color resources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 258
Grayscale resources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 259
Line resources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 259
Block . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 260
Caca . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 261
Caca limitations and bugs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 262
Cairolatex . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 262
Canvas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 264
Cgm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 265
Cgm font . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 266
Cgm fontsize . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 267
Cgm linewidth . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 267
Cgm rotate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 267
Cgm solid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 267
Cgm size . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 267
Cgm width . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 267
Cgm nofontlist . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 268
Context . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 268
Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 269
Calling gnuplot from ConTeXt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 270
Debug . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 270
Domterm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 270
Animate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 270
Dumb . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 270
Dxf . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 271
Emf . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 271
Epscairo . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 272
Epslatex . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 272

20

gnuplot 6.0

CONTENTS

Epson 180dpi . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 275
Fig . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 275
Gif . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 276
Animate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 277
Optimize . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 277
Fonts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 277
Gpic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 277
Grass . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 278
HP terminals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 278
Hpgl . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 278
Imagen. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 279

Jpeg . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 279
Kittycairo . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 280
Kittygd . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 280
Latex . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 281
Linux console . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 281
Lua . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 281
Lua tikz . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 281
Pbm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 284
Pcl5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 284
Pdfcairo . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 285
Pict2e . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 286
Pm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 287
Png . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 287
Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 288
Pngcairo . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 288
Postscript . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 289
Editing postscript . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 291
Postscript fontfile . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 291
Postscript prologue. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 292

Postscript adobeglyphnames . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 292
Pslatex and pstex . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 293
Pstricks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 294
Qt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 295
Regis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 296
Sixelgd . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 296
Svg . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 297
Svga . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 298
Tek40 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 298
Tek410x . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 298

CONTENTS

gnuplot 6.0

21

Texdraw . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 298
Tgif . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 299
Tikz . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 300
Tkcanvas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 300
Webp . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 302
Windows . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 302
Graph-menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 303
Printing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 304
Text-menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 304
Wgnuplot.mnu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 305
Wgnuplot.ini . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 305
Wxt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 306
X11 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 307
X11 fonts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 309
Command-line options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 309
Color resources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 310
Grayscale resources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 311
Line resources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 311
X11 pm3d resources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 312
X11 other resources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 312
Xlib . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 312

V

Index

312

22

gnuplot 6.0

Part I

Gnuplot
Copyright
Copyright (C) 1986 - 1993, 1998, 2004, 2007
Copyright (C) 2004-2023 various authors

Thomas Williams, Colin Kelley

Permission to use, copy, and distribute this software and its documentation for any purpose with or without
fee is hereby granted, provided that the above copyright notice appear in all copies and that both thatcopyright notice and this permission notice appear in supporting documentation.
Permission to modify the software is granted, but not the right to distribute the complete modified sourcecode. Modifications are to be distributed as patches to the released version. Permission to distribute binaries
produced by compiling modified sources is granted, provided you
1. distribute the corresponding source modifications from thereleased version in the form of a patch file along with the binaries,
2. add special version identification to distinguish your version
in addition to the base release version number,
3. provide your name and address as the primary contact for the
support of your modified version, and
4. retain our contact information in regard to use of the base software.

Permission to distribute the released version of the source code along with corresponding source modificationsin the form of a patch file is granted with same provisions 2 through 4 for binary distributions.
This software is provided "as is" without express or implied warranty to the extent permitted by applicablelaw.
AUTHORS
Original Software:
Thomas Williams, Colin Kelley.
Gnuplot 2.0 additions:
Russell Lang, Dave Kotz, John Campbell.
Gnuplot 3.0 additions:
Gershon Elber and many others.
Gnuplot 4.0 and subsequent releases:
See list of contributors at head of this document.

Introduction
Gnuplot is a portable command-line driven graphing utility for Linux, OS/2, MS Windows, macOS, VMS,
and many other platforms. The source code is copyrighted but freely distributed (i.e., you don’t have to
pay for it). It was originally created to allow scientists and students to visualize mathematical functions anddata interactively, but has grown to support many non-interactive uses such as web scripting. It is also used
as a plotting engine by third-party applications like Octave. Gnuplot has been supported and under active
development since 1986.
Gnuplot can generate many types of plot in 2D and 3D. It can draw using lines, points, boxes, contours,
vector fields, images, surfaces, and associated text. It also supports specialized graphs such as heat maps,
spider plots, polar projection, histograms, boxplots, bee swarm plots, and nonlinear coordinates.
Gnuplot supports many different types of output: interactive screen terminals (with mouse and hotkey
input), direct output to pen plotters or modern printers, and output to many file formats (eps, emf, fig,
jpeg, LaTeX, pdf, png, postscript, ...). Gnuplot is easily extensible to include new output modes. A recent
example is support for webp animation. Mouseable plots embedded in web pages can be generated using
the svg or HTML5 canvas terminal drivers.
The command language of gnuplot is case sensitive, i.e. commands and function names written in lowercase
are not the same as those written in capitals. All command names may be abbreviated as long as thegnuplot 6.0

23

abbreviation is not ambiguous. Any number of commands may appear on a line, separated by semicolons(;). Strings may be set off by either single or double quotes, although there are some subtle differences. See
syntax (p. 67) and quotes (p. 68) for more details. Example:
set title "My First Plot";

plot 'data';

print "all done!"

Commands may extend over several input lines by ending each line but the last with a backslash (\). The
backslash must be the last character on each line. The effect is as if the backslash and newline were not there.
That is, no white space is implied, nor is a comment terminated. Therefore, commenting out a continued line
comments out the entire command (see comments (p. 33)). But note that if an error occurs somewhere
on a multi-line command, the parser may not be able to locate precisely where the error is and in that casewill not necessarily point to the correct line.
In this document, curly braces ({}) denote optional arguments and a vertical bar (|) separates mutually
exclusive choices. Gnuplot keywords or help topics are indicated by backquotes or boldface (whereavailable). Angle brackets (<>) are used to mark replaceable tokens. In many cases, a default value of thetoken will be taken for optional arguments if the token is omitted, but these cases are not always denotedwith braces around the angle brackets.
For built-in help on any topic, type help followed by the name of the topic or help ? to get a menu ofavailable topics.
A large set of demo plots is available on the web page http://www.gnuplot.info/demo/
When run from command line, gnuplot is invoked using the syntax
gnuplot {OPTIONS} file1 file2 ...

where file1, file2, etc. are input files as in the load command. Options interpreted by gnuplot may comeanywhere on the line. Files are executed in the order specified, as are commands supplied by the -e option,for example
gnuplot

file1.in-e "reset"

file2.in

The special filename "-" is used to force reading from stdin. Gnuplot exits after the last file is processed. If
no load files are named, Gnuplot takes interactive input from stdin. See help batch/interactive (p. 31)
for more details. See command-line-options (p. 31) for more details, or typegnuplot --help

In sessions with an interactive plot window you can hit ’h’ anywhere on the plot for help about hotkeys(p. 61) and mousing (p. 187) features.

Seeking-assistance / Bugs
The canonical gnuplot home page can be found at http://www.gnuplot.info
Before seeking help, please check file FAQ.pdf or the above website for a FAQ (Frequently Asked
Questions) list.
Another resource for help with specific plotting problems (not bugs) is
https://stackoverflow.com/questions/tagged/gnuplot

Bug reports and feature requests should be uploaded to the trackers at
https://sourceforge.net/p/gnuplot/_list/tickets

Please check previous reports to see if the bug you want to report has already been fixed in a newer version.
When reporting a bug or posting a question, please include full details of the gnuplot version, the terminal
type, and the operating system. A short self-contained script demonstrating the problem is very helpful.
Instructions for subscribing to gnuplot mailing lists may be found via the gnuplot development website
http://sourceforge.net/projects/gnuplot
Please note that before you write to any of the gnuplot mailing lists you must first subscribe to the list. This
helps reduce the amount of spam.
The address for mailing to list members is:24

gnuplot 6.0
gnuplot-info@lists.sourceforge.net

A mailing list for those interested in the development version of gnuplot is:
gnuplot-beta@lists.sourceforge.net

New features in version 6
Version 6 is the latest major release in a history of gnuplot development dating back to 1986. It follows major
version 5 (2015) and subsequent minor version releases 5.2 (2017) and 5.4 (2020). Development continues ina separate unreleased branch in the project git repository on SourceForge.
Some features described in this document are present only if chosen and configured at the time gnuplot iscompiled from source. To determine what configuration options were used to build the particular copy ofgnuplot you are running, type show version long.

Function blocks and scoped variables
This version of gnuplot introduces a mechanism for invoking a block of standard gnuplot commands as acallable function. A function block can accept from 0 to 9 parameters and returns a value. Function blocks
can be used to calculate and assign a new value to a variable, to combine with other functions and operators,
or to perform a repetitive task preparing data. There are three components to this mechanism. See local(p. 118), scope (p. 64), function blocks (p. 114), return (p. 148).
• The local qualifier allows optional declaration of a variable or array whose scope is limited to theduration of execution of the program unit in which it is found. These units currently include executionof a load or call statement, function block evaluation, and the code block in curly brackets following
an if, else, do for, or while statement. If the name of a local variable duplicates the name of a global
variable, the global variable is shadowed until exit from the local scope.
• The function command declares a named function block (effectively an array of strings) containing
gnuplot commands. When the function block is invoked, commands are executed successively until theend of the block or until a return command is encountered.
• The return <expression> command terminates execution of a function block. The result of evaluating <expression> is returned as the value of the function. Anywhere outside a function block return
acts like exit.
For an example of using this mechanism to define and plot a non-trivial function that is too complicated fora simple one-line definition f(x) = ... please see function block.dem

Special and complex-valued functions
Gnuplot 6 provides an expanded set of complex-valued functions and updated versions of some functions
that were present in earlier versions.
• New: Riemann zeta function with complex domain and range. See zeta (p. 49).
• Updated lower incomplete gamma function with improved domain and precision. Complex arguments
accepted. See igamma (p. 44).
• New upper incomplete gamma function (real arguments only). See uigamma (p. 47).
• Updated incomplete beta function with improved domain and precision. See ibeta (p. 44).
• New function for the inverse incomplete gamma function. See invigamma (p. 44).
• New function for the inverse incomplete beta function. See invibeta (p. 44).

gnuplot 6.0

25• New complex function LambertW(z,k) returns the kth branch of multivalued function W k(z). Notethat the older function lambertw(x) = real(LambertW( real(z), 0 )). See LambertW (p. 44).
• New complex function lnGamma(z). Note that existing function lgamma(x) = real(lnGamma(real(z)).
See lnGamma (p. 45).
• Complex function conj(z) returns the complex conjugate of z.
• Synchrotron function F(x), see SynchrotronF (p. 45).
• acosh(z) domain extended to cover negative real axis.
• asin(z) asinh(z) improved precision for complex arguments.
• Predefined variable I = sqrt(-1) = {0,1} for convenience. This is useful because gnuplot does not accept{a,b} as a valid complex constant but does accept (a + b*I) as a valid complex expression.
Additional special functions are supported if a suitable external library is found at build time. See special functions (p. 45).
• Complex Bessel functions Iν(z), Jν(z), Kν(z), Yν(z) of order ν (real) with complex argument z. See
BesselK (p. 43).
• Complex Hankel functions H1ν(z), H2ν(z) of order ν with complex z. See BesselH1 (p. 43).
• Complex Airy functions Ai(z), Bi(z).
• Complex exponential integral of order n. See expint (p. 43).
• Fresnel integrals C(x) and S(x). See FresnelC (p. 43).
• Function VP fwhm(sigma,gamma) returns the full width at half maximum of the Voigt profile. See
VP (p. 40), VP fwhm (p. 40).

New plot styles• The plot style with surface works in 2D polar coordinates to produce a solid-fill gridded representationof the plane, colored by weighted contributions from an arbitrary set of input points. This is analogous
to the use of dgrid3d and style with pm3d to produce a 3D gridded surface. See set polar grid(p. 211) and polar heatmap (p. 90).
• New 2D plot style with sectors is an alternative to generating a full polar gridded surface. For each
input data point it generates a single annular wedge in a conceptual polar grid. Unlike polar modewith surface it can be used in either a polar or cartesian coordinate graph.
• Plot style with lines now has a filter option sharpen. This filter detects spikes in a function plot thatappear truncated in the output because the peak lies between two x-coordinates at which the function
has been sampled. It adds a new sample point at the location of each such peak. See filters (p. 128).
• Although it is not strictly speaking a new plot style, the combination of the concave hull filter withalong-path smoothing of filled areas allows creation of ’blobby region’ plots showing, for example, theextents of overlapping data clusters. See concavehull (p. 129).
• 3D plot style with pm3d accepts an optional modifier zclip [zmin:zmax] that selects only a slice ofthe full surface. Successive plots with incremental changes to the clipping limits can be used to animate
a cross-sectional cutaway view in 3D or to create a filled area contour map. This is automated by a
new plot style with contourfill that is particularly useful in 2D projection. See contourfill (p. 77).

Hulls, masks, and smoothing• A cluster of 2D points can be replaced by its bounding polygon using the new filter convexhull. A
path-smoothed bounding curve can be plotted as a filled area using "convexhull smooth path withfilledcurves". See convexhull (p. 128).

26

gnuplot 6.0• An alternative filter concavehull generates a bounding polygon that is not necessarily convex; instead
it forms a χ-shape determined by a characteristic length parameter that controls the degree of concavity.
This essentially draws a blob around the data points. See concavehull (p. 129).
• A convex hull or other polygon can be used as a mask to display only selected portions of a pm3d
surface or an image plot. See new plot style with mask (p. 89) (defines a mask) and keyword mask
(applies the mask to a subsequent plot component).
• curve smoothing using along-path cubic splines suitable for closed curves or for 2D curves that are notmonotonic on x. See smooth path (p. 132). This allows smoothing of hulls and masks.
• cubic spline smoothing of 3D lines. See splot smooth csplines (p. 132)
• Smoothing options apply to plotting with filledcurves (p. 78) {above|below|between}.
• New keyword period for smoothing periodic data. See smooth kdensity (p. 134).

Named palettes• The current palette can be saved to a named colormap for future use. See set colormap (p. 155).
• pm3d and image plots can specify a previously saved palette by name. This permits the use of multiple
palettes in a single plot command. See colorspec palette (p. 58).
• Named palette colormaps can be manipulated as arrays of 32-bit ARGB color values. This permits
addition of alpha-channel values or other modifications not easily specified in a set palette command.
• There is a new predefined color scheme set palette viridis.
• Palettes read from a file or datablock (set palette file) may be specified either using fractional color
components or 24-bit packed RGB values.

New data formats• The sparse matrix=(cols,rows) option to plot and splot generates a uniform pixel grid into which
individual pixel values may be loaded in any order. This is useful for plotting heat maps from incomplete
data. See sparse (p. 248).
• During input of non-uniform matrix data, column(0) now returns the linear ordering of matrix elements.
I.e. for element A[i,j] in an MxN matrix A, column(0)/M gives the row index i, and column(0)%M
gives the column index j.

New built-in functions and array operations• palette(z) returns the current RGB palette color mapping z into cbrange.
• rgbcolor("name") returns the 32bit ARGB value for a named color.
• index( Array, element ) returns the first index i for which Array[i] is equal to element. See arrays(p. 52).
• User-defined functions allow an array as a parameter. Example: dot(A,B) = sum [i=1:|A|] A[i]*B[i]• Array slices are generated by appending a range to the array name. Array[n] is single element. Array[n:n+5] is a six element slice of the original array. See arrays (p. 52), slice (p. 53).
• split("string", "separator") unpacks the fields in a string into an array of strings. See split (p. 48).
• join(array, "separator") is the complement to split. It concatenates the elements of a string array
into a single string with field separators. See join (p. 48).
• stats <non-existent file> yields a testable value. See stats test (p. 252).
• stats $vgrid finds min/max/mean/stddev of voxels in grid

gnuplot 6.0

27

Program control flow
• New syntax if ... else if ... else ...
• XDG base directory conventions for configuration preferences are supported. The program reads
initial commands from $XDG CONFIG HOME/gnuplot/gnuplotrc. Session command history is
saved to $XDG STATE HOME/gnuplot history. If these files are not found, $HOME/.gnuplot and$HOME/.gnuplot history are used as in previous gnuplot versions.
• unset warnings suppresses output of warning messages to stderr.
• warn "message" prints filename, line number and message to stderr.
• Exception handling for the "fit" command. Control always returns to the next line of input, even in
the case of fit errors. On return, FIT ERROR is non-zero if an error occurred. This allows scripted
recovery from a bad fit. See fit error recovery (p. 111).

Multiplots
Commands executed during initial creation of a multiplot are now stored in a datablock $GPVAL LAST MULTIPLOT. They can be replayed by the new command remultiplot. Certain saved commands that would be problematic during replay are not reexecuted. Note that the regenerated multiplot may
not exactly match the original if graphics settings (axis ranges, logscale, etc) have changed in the interim.
The following sequence of commands will save both the original graphics state and the multiplot commands
to a script file that can be reloaded later.
save "my_multiplot.gp"
set multiplot... various commands to generate the component plots ...
unset multiplot
set print "my_multiplot.gp" append
print $GPVAL_LAST_MULTIPLOT
unset print• The replot command will check to see if the most recent plot command was part of a completed
multiplot. If so, it will execute remultiplot instead of reexecuting that single plot command.
• EXPERIMENTAL. Replot requests generated by window events, mouse events, or hot keys in a displayed multiplot will call remultiplot if appropriate. This means, for example, that you can now
resize a multiplot displayed on the screen. However the mouse coordinate readout and thus zoom/pan
operations are still based solely on the axis settings for the final component plot, as was the case inearlier gnuplot versions. Because the commands stored in $GPVAL LAST MULTIPLOT may not be
sufficient to recreate the appropriate graphics settings for each component plot, mousing in a multiplot
may not act as you would like. This will be improved in the future.

New terminals and terminal options• New terminals kittygd and kittycairo provide in-window graphics for terminal emulators that support
the kitty protocol. Kitty is an alternative to sixel graphics that offers full 24-bit RGB color. See
kittycairo (p. 280).
• New terminal block for text-mode pseudo-graphics uses Unicode block or Braille characters to offer
improved resolution compared to the dumb or caca terminals.
• New terminal webp generates a single frame or an animation sequence using webp encoding. Frames
are generated using pngcairo, then encoded through the WebPAnimEncoder API exported by libwebp
and libwebpmux.

28

gnuplot 6.0• Terminals that use the same window for text entry and graphical display, including dumb, sixel,
kitty, and block now respond to keyboard input during a pause mouse command. While paused,
they interpret keystrokes in the same way that a mousing terminal would. See pseudo-mousing(p. 120). For example the left/right/up/down arrow keys change the view angle of 3D plots andperform incremental pan/zoom steps for 2D plots.

Watchpoints
Watchpoints are target values associated with individual plots in a graph. As that plot is drawn, each component line segment is monitored to see if its endpoints bracket the target value of a watchpoint coordinate(x, y, or z) or function f(x,y). If a match is found, the [x,y] coordinates of the match point are saved forlater use. See watchpoints (p. 69). Possible uses include• Find the intersection points of two curves• Find zeros of a function• Find and notate where a dependent variable (y or z) or function f(x,y) crosses a threshold value• Use the mouse to track values along multiple plots simultaneously

Week-date time support
The Covid-19 pandemic that began in 2020 generated increased interest in plotting epidemiological data,
which is often tabulated using a "week date" reporting convention. Deficiencies with gnuplot support forthis convention were remedied and the support for week-date time was extended.
• Time specifier format %W has been brought into accord with the ISO 8601 week date standard.
• Time specifier format %U has been brought into accord with the CDC/MMWR week date standard.
• New function tm week(time, std) returns ISO or CDC standard week of year.
• New function weekdate iso(year, week, day) converts ISO standard week date to calendar time.
• New function weekdate cdc(year, week, day) converts CDC standard week date to calendar time.

Other new features• Time units for setting major and minor tics. Both major and minor tics along a time axis now
accept tic intervals given in units of minutes/hours/days/weeks/months/years. See set xtics (p. 235),
set mxtics time (p. 192).
• The character sequence $# in a using specifier evaluates to the total number of columns available inthe current line of data. For example plot FOO using 0:(column($# - 1)) plots the last-but-one
field of each row.
• keyword binvalue=avg plots the average, rather than the sum, of binned data.
• set colorbox bottom places a horizontal color box underneath the plot rather than a vertical box
on the right.
• Improved rendering of intersecting pm3d surfaces - overlapping surface tiles are split into two pieces
along the line of intersection so that tiles from one surface do not incorrectly protrude though the othersurface.
• User-controlled spotlight added to the pm3d lighting model. See set pm3d spotlight (p. 207).
• New options to force total key width and number of columns. See key layout (p. 177).
• set pm3d border retrace draws a border around each pm3d quadrangle in the same color as thefilled area. In principle this should have no visible effect, but it prevents some display modes likeglitchy pdf or postscript viewers from introducing aliasing artifacts.

gnuplot 6.0

29• set isotropic adjusts the axis scaling in both 2D and 3D plots such that the x, y, and z axes all havethe same scale.
• Change: Text rotation angle is not limited to integral degrees.
• Special (non-numerical) linetypes lt nodraw, lt black, lt bgnd See special linetypes (p. 60).
• Data-driven color assignments in histogram plots. See histograms colors (p. 85).
• The position of the key box can be manually tweaked by specifying an offset to be added to whatever
position the program would otherwise use. See set key offset (p. 179).
• A keyentry with text but no plot style can be used to generate a secondary title in the key spanningthe entire width of the key. For example plot A, keyentry "left-justified text" left, B This canalso be used to create a key with two columns of text by providing both a text string and a title. See
keyentry (p. 177).

Brief summary of features introduced in version 5
Features introduced in 5.4• Expressions and functions use 64-bit integer arithmetic. See integer (p. 42)• 2D plot styles polygons (p. 91), spiderplot (p. 93), arrows (p. 71)• 3D plot styles boxes (p. 72), circles (p. 76), polygons (p. 91), isosurface (p. 100) and otherrepresentations of gridded voxel data
• Data preprocessing filter zsort (p. 130)
• Construction of customized keys using keyentry (p. 177)
• New LaTeX terminal pict2e supersedes older terminals latex (p. 281), emtex (p. 281), eepic(p. 281), and tpic (p. 281). The older terminals are no longer built by default• set pixmap imports a png/jpeg/gif image as a pixmap that can be scaled and positioned anywhere
in a plot or on the page
• Enhanced text mode accepts \U+xxxx (xxxx is a 4 or 5 character hexadecimal) as representing aUnicode code point that is converted to the corresponding UTF-8 byte sequence on output• Revised syntax for with parallelaxes allows convenient iteration inside the plot command, similar toplot styles histogram and spiderplot

Features introduced in 5.2• Nonlinear coordinate systems (see set nonlinear (p. 192))• Automated binning of data (see bins (p. 128))• 2D beeswarm plots. See set jitter (p. 175)
• 3D plot style zerrorfill (p. 100)
• 3D lighting model provides shading and specular highlighted (see lighting (p. 207)).
• Array data type, associated commands and operators. See arrays (p. 52).
• New terminals sixelgd, domterm• New format descriptors tH tM tS handle relative times (interval lengths).
(p. 170).

See time specifiers

30

gnuplot 6.0

Features introduced in 5.0• Terminal independent dash types.
• The default sequence of colors used for successive elements in a plot is more easily distinguished byusers with color-vision defects.
• New plot types with parallelaxes, with table.
• Hypertext labels activated by a mouse-over event.
• Explicit sampling ranges in 2D and 3D function plots and pseudofiles ’+’ and ’++’.
• Plugin support through new command import that attaches a user-defined function name to a function
provided by an external shared object.

Differences between versions 5 and 6
Some changes introduced in version 5 could cause certain scripts written for earlier versions of gnuplot to
fail or to behave differently. There are very few such changes in version 6.

Plot style details
Apart from adding entirely new plot styles, version 6 also makes a few tweaks to existing plot styles.
• More terminals (png/jpeg/sixel/kitty) scale the size of a "dot" by the current line width. Some otherterminals already did this.
• Plot styles that draw error bars place a gap at the position of the data point. The size of the gap iscontrolled by set pointintervalbox.
• Multiplots can now be redrawn or rescaled (see multiplots (p. ??)). Because of this it is no longer
possible to read in-line data from pseudofile ’-’. Use a data block instead.

Deprecated syntax
Deprecated in version 5.4, removed in 6.0# use of a file containing `reread` to perform iteration
N = 0; load "file-containing-reread";file content:
N = N+1
plot func(N,x)
pause -1
if (N<5) reread

Current equivalent
do for [N=1:5] {plot func(N, x)
pause -1}

Deprecated in version 5.4, removed in 6.0
set dgrid3d ,,foo# no keyword to indicate meaning of foo

Current equivalent
set dgrid3d qnorm foo # (example only; qnorm is not the only option)

Deprecated in version 5.0, removed in 6.0
set style increment user

gnuplot 6.0

31

Current equivalent
use "set linetype" to redefine a convenient range of linetypes

Deprecated in version 5.0, removed in 6.0
set clabel

Current equivalent`set clabel "format"` is replaced by `set cntrlabel format "format"`.
`unset clabel` is replaced by `set cntrlabel onecolor`.

Deprecated in version 5.0, removed in 6.0
show palette fit2rgbformulae

Demos and Online Examples
The gnuplot distribution contains a collection of examples in the demo directory. You can browse on-line
versions of these examples produced by the png, svg, and canvas terminals at http://gnuplot.info/demos
The commands that produced each demo plot are shown next to the plot, and the corresponding gnuplot
script can be downloaded to serve as a model for generating similar plots.

Batch/Interactive Operation
Gnuplot may be executed in either batch or interactive modes, and the two may even be mixed together.
Command-line arguments are assumed to be either program options or names of files containing gnuplot
commands. Each file or command string will be executed in the order specified. The special filename "-" isindicates that commands are to be read from stdin. Gnuplot exits after the last file is processed. If no load
files and no command strings are specified, gnuplot accepts interactive input from stdin.

Command line options
Gnuplot accepts the following options on the command line
-V, --version-h, --help-p, --persist-d, --default-settings-s, --slow-e "command1; command2; ..."-c scriptfile ARG1 ARG2 ...

-p tells the program not to close any remaining interactive plot windows when the program exits.
-d tells the program not to execute any private or system initialization (see initialization (p. 64)).
-s tells the program to wait for slow font initialization on startup. Otherwise it prints an error and continues
with bad font metrics.
-e "command" tells gnuplot to execute that single command before continuing.
-c is equivalent to -e "call scriptfile ARG1 ARG2 ...". See call (p. 102).

32

gnuplot 6.0

ExamplesTo launch an interactive session:
gnuplot

To execute two command files "input1" and "input2" in batch mode:
gnuplot input1 input2

To launch an interactive session after an initialization file "header" and followed by another command file"trailer":
gnuplot header - trailer

To give gnuplot commands directly in the command line, using the "-persist" option so that the plot remains
on the screen afterwards:
gnuplot -persist -e "set title 'Sine curve'; plot sin(x)"To set user-defined variables a and s prior to executing commands from a file:gnuplot -e "a=2; s='file.png'" input.gpl

Canvas size
This documentation uses the term "canvas" to mean the full drawing area available for positioning the plot
and associated elements like labels, titles, key, etc. NB: For information about the HTML5 canvas terminal
see set term canvas (p. 264).
set term <terminal type> size <XX>, <YY> controls the size of the output file, or "canvas". By
default, the plot will fill this canvas.
set size <XX>, <YY> scales the plot itself relative to the size of the canvas. Scale values less than 1 willcause the plot to not fill the entire canvas. Scale values larger than 1 will cause only a portion of the plot to
fit on the canvas. Please be aware that setting scale values larger than 1 may cause problems.
Example:set size 0.5, 0.5
set term png size 600, 400
set output "figure.png"
plot "data" with lines

These commands produce an output file "figure.png" that is 600 pixels wide and 400 pixels tall. The plot
will fill the lower left quarter of this canvas.
Note: In early versions of gnuplot some terminal types used set size to control the size of the output canvas.
This was deprecated in version 4.

Command-line-editing
Command-line editing and command history are supported using either an external gnu readline library,an external BSD libedit library, or a built-in equivalent. This choice is a configuration option at the time
gnuplot is built.
The editing commands of the built-in version are given below. Please note that the action of the DEL key
is system-dependent. The gnu readline and BSD libedit libraries have their own documentation.

gnuplot 6.0

33

Command-line Editing Commands
Character
^B
^F
^A
^E
^H
DEL
^D
^K
^L
^U
^W
^V
TAB
^P
^N
^R

FunctionLine Editing
move back a single character.
move forward a single character.
move to the beginning of the line.
move to the end of the line.
delete the previous character.
delete the current character.
delete current character. EOF if line is empty.
delete from current position to the end of line.
redraw line in case it gets trashed.
delete the entire line.
delete previous word.
inhibits the interpretation of the following key as editing command.
performs filename-completion.
History
move back through history.
move forward through history.
starts a backward-search.

Comments
The comment character # may appear almost anywhere in a command line, and gnuplot will ignore therest of that line. A # does not have this effect inside a quoted string. Note that if a commented line ends
in ’\’ then the subsequent line is also treated as part of the comment.
See also set datafile commentschars (p. 163) for specifying a comment character for data files.

Coordinates
The commands set arrow, set key, set label and set object allow you to draw something at an arbitrary
position on the graph. This position is specified by the syntax:{<system>} <x>, {<system>} <y> {,{<system>} <z>}

Each <system> can either be first, second, polar, graph, screen, or character.
first places the x, y, or z coordinate in the system defined by the left and bottom axes; second places itin the system defined by the x2,y2 axes (top and right); graph specifies the area within the axes — 0,0 is
bottom left and 1,1 is top right (for splot, 0,0,0 is bottom left of plotting area; use negative z to get to thebase — see set xyplane (p. 239)); screen specifies the screen area (the entire area — not just the portion
selected by set size), with 0,0 at bottom left and 1,1 at top right. character coordinates are used primarily
for offsets, not absolute positions. The character vertical and horizontal size depend on the current font.
polar causes the first two values to be interpreted as angle theta and radius r rather than as x and y. This
could be used, for example, to place labels on a 2D plot in polar coordinates or a 3D plot in cylindricalcoordinates.
If the coordinate system for x is not specified, first is used. If the system for y is not specified, the one used
for x is adopted.
In some cases, the given coordinate is not an absolute position but a relative value (e.g., the second position
in set arrow ... rto). In most cases, the given value serves as difference to the first position. If the given
coordinate belongs to a log-scaled axis, a relative value is interpreted as multiplier. For example,
set logscale x
set arrow 100,5 rto 10,2

34

gnuplot 6.0

plots an arrow from position 100,5 to position 1000,7 since the x axis is logarithmic while the y axis is linear.
If one (or more) axis is timeseries, the appropriate coordinate should be given as a quoted time string
according to the timefmt format string. See set xdata (p. 231) and set timefmt (p. 225). Gnuplot
will also accept an integer expression, which will be interpreted as seconds relative to 1 January 1970.

Datastrings
Data files may contain string data consisting of either an arbitrary string of printable characters containing
no whitespace or an arbitrary string of characters, possibly including whitespace, delimited by double quotes.
The following line from a datafile is interpreted to contain four columns, with a text field in column 3:
1.000 2.000 "Third column is all of this text" 4.00

Text fields can be positioned within a 2-D or 3-D plot using the commands:
plot 'datafile' using 1:2:4 with labels
splot 'datafile' using 1:2:3:4 with labels

A column of text data can also be used to label the ticmarks along one or more of the plot axes. The example
below plots a line through a series of points with (X,Y) coordinates taken from columns 3 and 4 of the input
datafile. However, rather than generating regularly spaced tics along the x axis labeled numerically, gnuplot
will position a tic mark along the x axis at the X coordinate of each point and label the tic mark with text
taken from column 1 of the input datafile.
set xtics
plot 'datafile' using 3:4:xticlabels(1) with linespoints

There is also an option that will interpret the first entry in a column of input data (i.e. the column heading)as a text field, and use it as the key title for data plotted from that column. The example given below will
use the first entry in column 2 to generate a title in the key box, while processing the remainder of columns
2 and 4 to draw the required line:
plot 'datafile' using 1:(f($2)/$4) with lines title columnhead(2)Another example:
plot for [i=2:6] 'datafile' using i title "Results for ".columnhead(i)This use of column headings is automated by set datafile columnheaders or set key autotitle columnhead. See labels (p. 87), using xticlabels (p. 138), plot title (p. 142), using (p. 135), key autotitle(p. 177).

Enhanced text mode
Many terminal types support an enhanced text mode in which additional formatting information can beembedded in the text string. For example, "x^2" will write x-squared as we are used to seeing it, with asuperscript 2. This mode is selected by default when you set the terminal, but may be toggled afterward
using "set termoption [no]enhanced", or disabled for individual strings as in set label "x 2" noenhanced.
Note: For output to TeX-based terminals (e.g. cairolatex, pict2e, pslatex, tikz) all text strings should instead
use TeX/LaTeX syntax. See latex (p. 281).

gnuplot 6.0

Control
^
_
@
&
~

\U+

35

Enhanced Text Control Codes
ResultExplanationax
superscriptax
subscript
abcd
phantom box (occupies no width)d␣␣␣␣␣b inserts space of specified lengthã
overprints ’-’ on ’a’, raised by .8
times the current fontsize{/Times abc}
abc
print abc in font Times at current size{/Times*2 abc}
abc
print abc in font Times at twice current size{/Times:Italic abc}
abc
print abc in font Times with style italic{/Arial:Bold=20 abc} abc
print abc in boldface Arial font size 20\U+221E∞
Unicode point U+221E INFINITY

Examplea^x
a_x
a@^b_{cd}d&{space}b~a{.8-}The markup control characters act on the following single character or bracketed clause. The bracketed clausemay contain a string of characters with no additional markup, e.g. 2^{10}, or it may contain additional
markup that changes font properties. Font specifiers MUST be preceded by a ’/’ character that immediately
follows the opening ’{’. If a font name contains spaces it must be enclosed in single or double quotes.
Examples: The first example illustrates nesting one bracketed clause inside another to produce a boldface
A with an italic subscript i, all in the current font. If the clause introduced by :Normal were omitted thesubscript would be both italic and boldface. The second example illustrates the same markup applied tofont "Times New Roman" at 20 point size.
{/:Bold A_{/:Normal{/:Italic i}}}{/"Times New Roman":Bold=20 A_{/:Normal{/:Italic i}}}

The phantom box is useful for a@^b c to align superscripts and subscripts but does not work well foroverwriting a diacritical mark on a letter. For that purpose it is much better to use an encoding (e.g. utf8)
that contains letters with accents or other diacritical marks. See set encoding (p. 166). Since the box isnon-spacing, it is sensible to put the shorter of the subscript or superscript in the box (that is, after the @).
Space equal in length to a string can be inserted using the ’&’ character. Thus
'abc&{def}ghi'

would produce
'abc

ghi'.

The ’˜ ’ character causes the next character or bracketed text to be overprinted by the following characteror bracketed text. The second text will be horizontally centered on the first. Thus ’˜ a/’ will result in an’a’ with a slash through it. You can also shift the second text vertically by preceding the second text with anumber, which will define the fraction of the current fontsize by which the text will be raised or lowered. In
this case the number and text must be enclosed in brackets because more than one character is necessary. If
the overprinted text begins with a number, put a space between the vertical offset and the text (’˜ {abc}{.5000}’); otherwise no space is needed (’˜ {abc}{.5 — }’). You can change the font for one or both strings (’˜a{.5 /*.2 o}’ — an ’a’ with a one-fifth-size ’o’ on top — and the space between the number and the slash isnecessary), but you can’t change it after the beginning of the string. Neither can you use any other special
syntax within either string. Control characters must be escaped, e.g. ’˜ a{.8\^}’ to print â. See escapesequences (p. 35) below.
Note that strings in double-quotes are parsed differently than those enclosed in single-quotes. The majordifference is that backslashes may need to be doubled when in double-quoted strings.
The file "ps guide.ps" in the /docs/psdoc subdirectory of the gnuplot source distribution contains more
examples of the enhanced syntax, as does the demo enhanced utf8.dem

Escape sequences
The backslash character \ is used to escape single byte character codes or Unicode entry points.

36

gnuplot 6.0

The form \ooo (where ooo is a 3 character octal value) can be used to index a known character code ina specific font encoding. For example the Adobe Symbol font uses a custom encoding in which octal 245
represents the infinity symbol. You could embed this in an enhanced text string by giving the font nameand the character code "{/Symbol \245}". This is mostly useful for the PostScript terminal, which cannot
easily handle UTF-8 encoding.
You can specify a character by its Unicode code point as \U+hhhh, where hhhh is the 4 or 5 character
hexadecimal code point. For example the code point for the infinity symbol ∞ is \U+221E. This will be
converted to a UTF-8 byte sequence on output if appropriate. In a UTF-8 environment this mechanism is
not needed for printable special characters since they are handled in a text string like any other character.
However it is useful for combining forms or supplemental diacritical marks (e.g. an arrow over a letter torepresent a vector). See set encoding (p. 166), utf8 (p. 166), and the online unicode demo.

Environment
A number of shell environment variables are understood by gnuplot. None of these are required.
GNUTERM, if defined, is passed to "set term" on start-up. This can be overridden by a system or personal
initialization file (see startup (p. 64)) and of course by later explicit set term commands. Terminal
options may be included. E.g.
bash$ export GNUTERM="postscript eps color size 5in, 3in"

GNUHELP, if defined, sets the pathname of the HELP file (gnuplot.gih).
Initialization
atstart-upmay
searchfor
configuration
files$HOME/.gnuplot,and$XDG CONFIG HOME/gnuplot/gnuplotrc. On MS-DOS, Windows and OS/2, files in GNUPLOTor USERPROFILE are searched. For more details see startup (p. 64).
On Unix, PAGER is used as an output filter for help messages.
On Unix, SHELL is used for the shell command. On MS-DOS and OS/2, COMSPEC is used.
FIT SCRIPT may be used to specify a gnuplot command to be executed when a fit is interrupted — seefit (p. 105). FIT LOG specifies the default filename of the logfile maintained by fit.
GNUPLOT LIB may be used to define additional search directories for data and command files. The variable
may contain a single directory name, or a list of directories separated by a platform-specific path separator,
eg. ’:’ on Unix, or ’;’ on DOS/Windows/OS/2 platforms. The contents of GNUPLOT LIB are appended to
the loadpath variable, but not saved with the save and save set commands.
Several gnuplot terminal drivers access TrueType fonts via the gd library (see fonts (p. 54)). For theseterminals GDFONTPATH and GNUPLOT DEFAULT GDFONT may affect font selection.
The postscript terminal uses its own font search path. It is controlled by the environmental variable
GNUPLOT FONTPATH.
GNUPLOT PS DIR is used by the postscript driver to search for external prologue files. Depending on thebuild process, gnuplot contains either a built-in copy of those files or a default hardcoded path. You can use
this variable to have the postscript terminal use custom prologue files rather than the default prologue files.
See postscript prologue (p. 292).

Expressions
In general, any mathematical expression accepted by C, FORTRAN, Pascal, or BASIC is valid. The precedence of these operators is determined by the specifications of the C programming language. White space(spaces and tabs) is ignored inside expressions.
Note that gnuplot uses both "real" and "integer" arithmetic, like FORTRAN and C. Integers are entered as"1", "-10", etc; reals as "1.0", "-10.0", "1e1", 3.5e-1, etc. The most important difference between the twognuplot 6.0

37

forms is in division: division of integers truncates: 5/2 = 2; division of reals does not: 5.0/2.0 = 2.5. In
mixed expressions, integers are "promoted" to reals before evaluation: 5/2e0 = 2.5. The result of divisionof a negative integer by a positive one may vary among compilers. Try a test like "print -5/2" to determine
if your system always rounds down (-5/2 yields -3) or always rounds toward zero (-5/2 yields -2).
The integer expression "1/0" may be used to generate an "undefined" flag, which causes a point to beignored. Or you can use the pre-defined variable NaN to achieve the same result. See using (p. 135) foran example.
Gnuplot can also perform simple operations on strings and string variables. For example, the expression("A" . "B" eq "AB") evaluates as true, illustrating the string concatenation operator and the string equality
operator.
A string which contains a numerical value is promoted to the corresponding integer or real value if used ina numerical expression. Thus ("3" + "4" == 7) and (6.78 == "6.78") both evaluate to true. An integer,
but not a real or complex value, is promoted to a string if used in string concatenation. A typical case is
the use of integers to construct file names or other strings; e.g. ("file" . 4 eq "file4") is true.
Substrings can be specified using a postfixed range descriptor [beg:end]. For example, "ABCDEF"[3:4] =="CD" and "ABCDEF"[4:*] == "DEF" The syntax "string"[beg:end] is exactly equivalent to calling thebuilt-in string-valued function substr("string",beg,end), except that you cannot omit either beg or end fromthe function call.

Complex values
Arithmetic operations and most built-in functions support the use of complex arguments. Complex constants
are expressed as {<real>,<imag>}, where <real> and <imag> must be numerical constants. Thus {0,1}represents ’i’. The program predefines a variable I = {0,1} on entry that can be used to generate complex
values in terms of other variables. Thus x + y*I is a valid expression but {x,y} is not. The real andimaginary components of complex value z can be extracted as real(z) and imag(z). The modulus is given byabs(z). The phase angle is given by arg(z).
Gnuplot’s 2D and 3D plot styles expect real values; toplot a complex-valued function f(z) with non-zero imaginary components you must plot the real or imaginaryπE0(z)component, or the modulus or phase. For example tophaserepresent the modulus and phase of a function f(z) withcomplex argument and complex result it is possible to-π
use the height of the surface to represent modulus anduse the color to represent the phase. It is convenient00Imag(z)to use a color palette in HSV space with component H
Real(z)(hue), running from 0 to 1, mapped to the range of thephase returned by arg(z), [-π:π], so that the color wraps
when the phase angle does. By default this would be at H = 0 (red). You can change this with the start
keyword in set palette so that some other value of H is mapped to 0. The example shown starts and wraps
at H = 0.3 (green). See set palette defined (p. 199), arg (p. 39), set angles (p. 149).
set palette model HSV start 0.3 defined (0 0 1 1, 1 1 1 1)
set cbrange [-pi:pi]
set cbtics ("-π" -pi, "π" pi)set pm3d corners2color c1
E0(z) = exp(-z)/z
I = {0,1}
splot '++' using 1:2:(abs(E0(x+I*y))):(arg(E0(x+I*y))) with pm3d

38

gnuplot 6.0

Constants
Integer constants are interpreted via the C library routine strtoll(). This means that constants beginningwith "0" are interpreted as octal, and constants beginning with "0x" or "0X" are interpreted as hexadecimal.
Floating point constants are interpreted via the C library routine atof().
Complex constants are expressed as {<real>,<imag>}, where <real> and <imag> must be numericalconstants. For example, {0,1} represents ’i’ itself; {3,2} represents 3 + 2i. The curly braces are explicitly
required here. The program predefines a variable I = {0,1} on entry that can be used to avoid typing the
explicit form. For example 3 + 2*I is the same as {3,2}, with the advantage that it can be used withvariable coefficient for the imaginary component. Thus x + y*I is a valid expression but {x,y} is not.
String constants consist of any sequence of characters enclosed either in single quotes or double quotes. The
distinction between single and double quotes is important. See quotes (p. 68).
Examples:1 -10 0xffaabb
1.0 -10. 1e1 3.5e-1{1.2, -3.4}"Line 1\nLine 2"'123\na\456'# integer constants# floating point constants# complex constant# string constant (\n is expanded to newline)# string constant (\ and n are ordinary characters)

gnuplot 6.0

39FunctionsArguments to math functions in gnuplot can be integer, real, or complex unless otherwise noted. Functions
that accept or return angles (e.g. sin(x)) treat angle values as radians, but this may be changed to degrees
using the command set angles.

Functionabs(x)
abs(x)
acos(x)acosh(x)airy(x)arg(x)
asin(x)asinh(x)atan(x)
atan2(y,x)
atanh(x)besj0(x)besj1(x)besjn(n,x)
besy0(x)besy1(x)besyn(n,x)
besi0(x)besi1(x)besin(n,x)
cbrt(x)ceil(x)conj(x)cos(x)
cosh(x)EllipticK(k)EllipticE(k)EllipticPi(n,k)
erf(x)
erfc(x)exp(x)
expint(n,x)
floor(x)gamma(x)ibeta(a,b,x)
inverf(x)igamma(a,z)
imag(x)int(x)
invnorm(x)invibeta(a,b,p)
invigamma(a,p)
LambertW(z,k)
lambertw(x)Math library and built-in functions
Returns (c indicates complex result)absolute value
p of x, |x|
length of x, real(x)2 + imag(x)2ccos−1 x (inverse cosine)ccosh−1 x (inverse hyperbolic cosine)real
Airy function Ai(x) for real x
complexthe phase of x, −π ≤arg(x)≤ πcsin−1 x (inverse sin)csinh−1 x (inverse hyperbolic sin)ctan−1 x (inverse tangent)
int or realtan−1 (y/x) (inverse tangent)ctanh−1 x (inverse hyperbolic tangent)real
J0 Bessel function of x in radians
real
J1 Bessel function of x in radiansint, real
Jn Bessel function of x in radiansreal
Y0 Bessel function of x in radiansreal
Y1 Bessel function of x in radiansint, real
Yn Bessel function of x in radians
real
Modified Bessel function of order 0, x in radians
real
Modified Bessel function of order 1, x in radiansint, real
Modified Bessel function of order n, x in radiansrealcube root of x (domain and range both limited to real)⌈x⌉, smallest integer not less than the real part of x
complexccomplex conjugate of x
ccos x, cosine of xccosh x, hyperbolic cosine of x in radians
real k ∈ (-1:1)
K(k) complete elliptic integral of the first kindreal k ∈ [-1:1]
E(k) complete elliptic integral of the second kindreal n<1, real k ∈ (-1:1)
Π(n, k) complete elliptic integral of the third kinderf(real(x)), error function of real(x)erfc(real(x)), 1.0 - error function of real(x)cex , exponentialfunction of xR∞
int n ≥ 0, real x ≥ 0
En (x) = 1 t−n e−xt dt, exponential integral of x⌊x⌋, largest integer not greater than the real part of x
Γ(x), gamma function of real(x)Γ(a+b) R x a−1t(1 − t)b−1 dt, incomplete beta
a, b > 0, x ∈ [0 : 1]
B(a, b, x) = Γ(a)Γ(b)0
inverse error function of real(x)R z a−1 −t
1complex, ℜ(a) > 0cincomplete gamma function P (a, z) = Γ(z)te dt
0compleximaginary part of x as a real number
realinteger part of x, truncated toward zero
inverse normal distribution function of real(x)realinverse incomplete beta function
realinverse incomplete gamma function
complex, intckth branch of complex Lambert W function
realprincipal branch (k=0) of Lambert W function
Arguments
int or realcomplex40

Function
lgamma(x)lnGamma(x)log(x)
log10(x)norm(x)rand(x)real(x)round(x)sgn(x)
Sign(x)sin(x)
sinh(x)sqrt(x)SynchrotronF(x)tan(x)
tanh(x)uigamma(a,x)

gnuplot 6.0

Arguments
realcomplexint

complexreal

real, real

voigt(x,y)

realzeta(s)complex

Math library and built-in functions
Returns (c indicates complex result)ln Γ(x) for real xcln Γ(x) valid over entire complex planecloge x, natural logarithm (base e) of xclog10 x, logarithm (base 10) of x
normal distribution (Gaussian) function of real(x)pseudo random number in the open interval (0:1)
real part of x⌊x⌉, integer nearest to the real part of x
1 if x > 0, -1 if x < 0, 0 if x = 0. imag(x) ignoredc
0 if x = 0, otherwise x/|x|c
sin x, sine of xcsinh
√ x, hyperbolic sine of x in radianscx, squareroot of x
R∞
F (x) = x x K 35 (ν) dνctan x, tangent of xctanh x, hyperbolic tangent of x in radians
R ∞ a−1 −t
1upper incomplete gamma function Q(a, x) = Γ(x)te dtxR exp(−t2 )yVoigt/Faddeeva function π (x−t)2 +y2 dt
Note: voigt(x, y) = real(faddeeva(x + iy))−scRiemann zeta function ζ(s) = Σ∞k=1 kFunction

Special functions from libcerf (only if available)
Arguments
Returns (c indicates complex result)cerf(z)cdawson(z)faddeeva(z)erfi(x)FresnelC(x)FresnelS(x)VP(x,σ,γ)
VP fwhm(σ,γ)

complexcomplexcomplex
real
real
real
real
real

Function
Ai(z)
Bi(z)
BesselH1(nu,z)BesselH2(nu,z)BesselJ(nu,z)BesselY(nu,z)BesselI(nu,z)

c
c
c

√ R
2
z
complex error function cerf (z) = 2π 0 e−t dt √2complex extension of Dawson’s integral D(z) = 2π e−z erf i(z)2scaled complex complementary error function w(z) = e−z erf c(−iz)
imaginary error functionR erf (x) = −i ∗ erf (ix)x
Fresnel integral C(x) = R 0 cos( π2 t2 )dtx
π 2
Fresnel integral S(x) = 0 sin(R ∞ 2 t )dt′
Voigt profile V P (x, σ, γ) = −∞ G(x ; σ)L(x − x′ ; γ)dx′
Voigt profile full width at half maximum value

Complex special functions from Amos library (only if available)
Arguments
Returns (c indicates complex result)complexcomplexreal, complex
real, complex
real, complex
real, complex
real, complex

c
c
c
c
c
c
c

complex Airy function Ai(z)complex Airy function Bi(z)(1)
Hν (z) Hankel function of the first kind(2)Hν (z) Hankel function of the second kindJν (z) Bessel function of the first kindYν (z) Bessel function of the second kindIν (z) modified Bessel function of the first kind

gnuplot 6.0

Function
BesselK(nu,z)expint(n,z)

Complex special functions from Amos library (only if available)
Arguments
Returns (c indicates complex result)real, complexcKν (z) modified
Bessel function of the second kindR∞
int n ≥ 0, complex z c En (z) = 1 t−n e−zt dt, exponential integral

Function
gprintf(”format”,x,...)
sprintf(”format”,x,...)
strlen(”string”)
strstrt(”string”,”key”)
substr(”string”,beg,end)
split(”string”,”sep”)
join(array,”sep”)
strftime(”timeformat”,t)strptime(”timeformat”,s)system(”command”)
trim(” string ”)
word(”string”,n)words(”string”)

String functions
Arguments
Returnsanystring result from applying gnuplot’s format parser
multiplestring result from C-language sprintf
stringnumber of characters in string
strings
int index of first character of substring ”key”
multiplestring ”string”[beg:end]
stringarray of substrings
array,string
concatenate array elements into a string
any
string result from applying gnuplot’s time parser
stringseconds since year 1970 as given in string s
stringstring containing output stream of shell command
stringstring without leading or trailing whitespace
string, int
returns the nth word in ”string”
stringreturns the number of words in ”string”

Functiontime(x)timecolumn(N,”timeformat”)
tm hour(t)tm mday(t)tm min(t)tm mon(t)tm sec(t)tm wday(t)tm week(t)tm yday(t)tm year(t)weekdate iso(year,week,day)
weekdate cdc(year,week,day)

Time functions
Arguments Returns
any
the current system time in seconds
int, string formatted time data from column N of input
time in sec the hour (0..23)
time in sec the day of the month (1..31)
time in sec the minute (0..59)
time in sec the month (0..11)
time in sec the second (0..59)
time in sec the day of the week (Sun..Sat) as (0..6)
time in sec week of year in ISO8601 ”week date” system (1..53)
time in sec the day of the year (0..365)
time in sec the year
int
time corresponding to ISO 8601 standard week date
int
time corresponding to CDC epidemiological week date

41

42

gnuplot 6.0

Functioncolumn(x)columnhead(x)exists(”X”)
hsv2rgb(h,s,v)
index(A,x)
palette(z)rgbcolor(”name”)
stringcolumn(x)valid(x)value(”name”)
voxel(x,y,z)

Arguments
int or string
int
stringh,s,v ∈ [0:1]array, any
realstringint or string
int
stringrealother gnuplot functions
Returns
numerical value of column x during datafile input
string containing first entry of column x in datafile.
returns 1 if a variable named X is defined, 0 otherwise.
24bit RGB color value.
integer i such that A[i] = x. 0 if no match.
24 bit RGB palette color mapped to z.
32bit ARGB color from name or string representation.
content of column x as a string
test validity of column x during datafile input
returns the value of the named variable.
value of the active grid voxel containing point (x,y,z)Integer conversion functions (int floor ceil round)Gnuplot integer variables are stored with 64 bits of precision if that is supported by the platform.
Gnuplot complex and real variables are on most platforms stored in IEEE754 binary64 (double) floating
point representation. Their precision is limited to 53 bits, corresponding to roughly 16 significant digits.
Therefore integers with absolute value larger than 2^53 cannot be uniquely represented in a floating point
variable. I.e. for large N the operation int(real(N)) may return an integer near but not equal to N.
Furthermore, functions that convert from a floating point value to an integer by truncation may not yield the
expected value if the operation depends on more than 15 significant digits of precision even if the magnitudeis small. For example int(log10(0.1)) returns 0 rather than -1 because the floating point representation isequivalent to -0.999999999999999... See also overflow (p. 197).
int(x) returns the integer part of its argument, truncated toward zero. If |x| > 2^63, i.e. too large torepresent as an integer, NaN is returned. If |x| > 2^52 the return value will lie within a range of neighboring
integers that cannot be distinguished due to limited floating point precision. See integer conversion(p. 42).
floor(x) returns the largest integer not greater than the real part of x. If |x| > 2^52 the true value cannot
be uniquely determined; in this case the return value is NaN. See integer conversion (p. 42).
ceil(x) returns the smallest integer not less than the real part of x. If |x| > 2^52 the true value cannot be
uniquely determined; in this case the return value is NaN. See integer conversion (p. 42).
round(x) returns the integer nearest to the real part of x. If |x| > 2^52 the true value cannot be uniquelydetermined; in this case the return value is NaN. See integer conversion (p. 42).

Elliptic integrals
The EllipticK(k) function returns the complete elliptic integral of the first kind, i.e. the definite integral
between 0 and pi/2 of the function (1 - k^2*sin^2(θ))^(-0.5). The domain of k is -1 to 1 (exclusive).
−1
R π/2 pEllipticK(k) = 0
1 − k 2 sin2 θdθ
The EllipticE(k) function returns the complete elliptic integral of the second kind, i.e. the definite integral
between 0 and pi/2 of the function (1 - k^2*sin^2(θ))^0.5. The domain of k is -1 to 1 (inclusive).
R π/2 pEllipticE(k) = 0
1 − k 2 sin2 θ dθThe EllipticPi(n,k) function returns the complete elliptic integral of the third kind, i.e. the definite integral
between 0 and pi/2 of the function (1 - k^2*sin^2(θ))^(-0.5) / (1 - n*sin^2(θ)). The parameter n mustbe less than 1, while k must lie between -1 and 1 (exclusive). Note that by definition EllipticPi(0,k) ==EllipticK(k) for all possible values of k.

gnuplot 6.0
EllipticPi(n, k) =

43

p
−1
R π/2 dθ(1 − n sin2 θ) 1 − k 2 sin2 θ
0Elliptic integral algorithm: B.C.Carlson 1995, Numerical Algorithms 10:13-26.
Complex Airy functions
Ai(z) and Bi(z) are the Airy functions of complex argument z, computed in terms of the modified Bessel
functions K and I. Supported via an external library containing routines by Donald E. Amos, Sandia National
Laboratories, SAND85-1018 (1985).
p
Ai(z) = π1 z3 K1/3 (ζ)ζ = 23 z 3/2pz
Bi(z) = 3 I−1/3 (ζ) + I1/3 (ζ)]
Complex Bessel functions
BesselJ(nu,z) is the Bessel function of the first kind J nu for real argument nu and complex argumentz. Supported via external library containing routines by Donald E. Amos, Sandia National Laboratories,
SAND85-1018 (1985).
BesselY(nu,z) is the Bessel function of the second kind Y nu for real argument nu and complex argumentz. Supported via external library containing routines by Donald E. Amos, Sandia National Laboratories,
SAND85-1018 (1985).
BesselI(nu,z) is the modified Bessel function of the first kind I nu for real argument nu and complex
argument z. Supported via external library containing routines by Donald E. Amos, Sandia National Laboratories, SAND85-1018 (1985).
BesselK(nu,z) is the modified Bessel function of the second kind K nu for real argument nu and complex argument z. Supported via external library containing routines by Donald E. Amos, Sandia National
Laboratories, SAND85-1018 (1985).
BesselH1(nu,z) and BesselH2(nu,z) are the Hankel functions of the first and second kind
H1(nu,z) = J(nu,z) + iY(nu,z)H2(nu,z) = J(nu,z) - iY(nu,z)

for real argument nu and complex argument z. Supported via external library containing routines by Donald
E. Amos, Sandia National Laboratories, SAND85-1018 (1985).
Expintexpint(n,z) returns the exponential integral of order n, where n is an integer >= 0. This is the integral
from 1 to infinity of t^(-n) e^(-tz) dt.
R∞
En (x) = 1 t−n e−xt dt
If your copy of gnuplot was built with support for complex functions from the Amos library, then for n>0
the evaluation uses Amos routine cexint [Amos 1990 Algorithm 683, ACM Trans Math Software 16:178]. In
this case z may be any complex number with -pi < arg(z) <= pi. expint(0,z) is calculated as exp(-z)/z.
If Amos library support is not present, z is limited to real values z >= 0.
Fresnel integrals FresnelC(x) and FresnelS(x)The cosine and sine Fresnel integrals are calculated using their relationship to the complex error function
erf(z). Due to dependence on erf(z), these functions are only available if libcerf library support is present.
Rx
Rx
C(x) = 0 cos( π2 t2 )dt S(x) = 0 sin( π2 t2 )dt
C(x) + iS(x) = 1+i
2 erf (z) where z =√π
2 (1 − i)x44gnuplot 6.0

Gamma
gamma(x) returns the gamma function of the real part of its argument. For integer n, gamma(n+1) =n!. If the argument is a complex value, the imaginary component is ignored. For complex arguments see
lnGamma (p. 45).
Igammaigamma(a, z) returns the lower incomplete gamma function P(a, z), [Abramowitz and Stegun (6.5.1); NISTDLMF 8.2.4]. If complex function support is present a and z may be complex values; real(a) > 0; For thecomplementary upper incomplete gamma function, see uigamma (p. 47).
R z a−1 −t
1te dt
igamma(a, z) = P (a, z) = z a γ ∗ (a, z) = Γ(z)0
One of four algorithms is used depending on a and z.
Case (1) When a is large (>100) and (z-a)/a is small (<0.2) use Gauss-Legendre quadrature with coefficientsfrom Numerical Recipes 3rd Edition section 6.2, Press et al (2007).
Case (2) When z > 1 and z > (a+2) use a continued fraction following Shea (1988) J. Royal Stat. Soc.
Series C (Applied Statistics) 37:466-473.
Case (3) When z < 0 and a < 75 and imag(a) == 0 use the series from Abramowitz & Stegun (6.5.29).
Otherwise (Case 4) use Pearson’s series expansion.
Note that convergence is poor in some regions of the full domain. If the chosen algorithm does not converge
to within 1.E-14 the function returns NaN and prints a warning.
If no complex function support is present the domain is limited to real arguments a > 0, z >= 0.
Invigamma
The inverse incomplete gamma function invigamma(a,p) returns the value z such that p = igamma(a,z).
p is limited to (0;1]. a must be a positive real number. The implementation in gnuplot has relative accuracy
that ranges from 1.e-16 for a<1 to 5.e-6 for a = 1.e10. Convergence may fail for a < 0.005.
Ibeta
ibeta(a,b,x) returns the normalized lower incomplete beta integral of real arguments a,b > 0, x in [0:1].
Γ(a+b) R x a−1
ibeta(a, b, x) = Γ(a)Γ(b)t(1 − t)b−1 dt
0
If the arguments are complex, the imaginary components are ignored. The implementation in gnuplot
uses code from the Cephes library [Moshier 1989, "Methods and Programs for Mathematical Functions",
Prentice-Hall].
Invibeta
The inverse incomplete beta function invibeta(a,b,p) returns the value z such that p = ibeta(a,b,z). a, b
are limited to positive real values and p is in the interval [0,1]. Note that as a, b approach zero (⪅ 0.05)
invibeta() approaches 1.0 and its relative accuracy is limited by floating point precision.
LambertW
Lambert W function with complex domain and range. LambertW( z, k ) returns the kth branch of thefunction W defined by the equation W(z) * exp(W(z)) = z. The complex value is obtained using Halley’s
method as described by Corless et al [1996], Adv. Comp. Math 5:329. The nominal precision is 1.E-13 but
convergence can be poor very close to discontinuities, e.g. branch points.

gnuplot 6.0

45

LnGammalnGamma(z) returns the natural log of the gamma function with complex domain and range. Implemented
using 14 term approximation following Lanczos [1964], SIAM JNA 1:86-96. The imaginary component of
the result is phase-shifted to yield a continuous surface everywhere except the negative real axis.
Random number generator
The function rand() produces a sequence of pseudo-random numbers between 0 and 1 using an algorithm
from P. L’Ecuyer and S. Cote, "Implementing a random number package with splitting facilities", ACM
Transactions on Mathematical Software, 17:98-111 (1991).
rand(0)

returns a pseudo random number in the open interval (0:1)
generated from the current value of two internal
32-bit seeds.
rand(-1)
resets both seeds to a standard value.
rand(x)for integer 0 < x < 2^31-1 sets both internal seeds
to x.
rand({x,y}) for integer 0 < x,y < 2^31-1 sets seed1 to x andseed2 to y.

Special functions with complex arguments
Some special functions with complex domain are provided through external libraries. If your copy of gnuplot
was not configured to link against these libraries then it will support only the real domain or will not provide
the function at all.
Functions requiring libcerf (http://apps.jcns.fz-juelich.de/libcerf) depend on configuration option –withlibcerf. This is the default. See cerf (p. 40), cdawson (p. 40), faddeeva (p. 40), erfi (p. 40), VP(p. 40), and VP fwhm (p. 40).
Complex Airy, Bessel, and Hankel functions of real order nu and complex arguments require a library containing routines implemented by Douglas E. Amos, Sandia National Laboratories, SAND851018 (1985). These routines may be found in netlib (http://netlib.sandia.gov) or in libopenspecfun (https://github.com/JuliaLang/openspecfun). The corresponding configuration option is –withamos=<library directory>. See Ai (p. 43), Bi (p. 43), BesselJ (p. 43), BesselY (p. 43), BesselI(p. 43), BesselK (p. 43), Hankel (p. 43). The complex exponential integral is provided by netlib or
libamos but not by libopenspecfun. See expint (p. 43).
Synchrotron function
The synchrotron function SynchrotronF(x) describes the power distribution spectrum of synchrotron radiation as a function of x given in units of the critical photon energy (i.e. critical frequency vc).
R∞
F (x) = x x K5/3 (ν) dν where K5/3 is a modified Bessel function of the second kind.
Chebyshev coefficients for approximation accurate to 1.E-15 are taken from MacLead (2000) NuclInstMethPhysRes A443:540-545.
Time functions
Time The time(x) function returns the current system time. This value can be converted to a datestring with the strftime function, or it can be used in conjunction with timecolumn to generate relative
time/date plots. The type of the argument determines what is returned. If the argument is an integer,time() returns the current time as an integer, in seconds from the epoch date, 1 Jan 1970. If the argument
is real (or complex), the result is real as well. If the argument is a string, it is assumed to be a format and it
is passed to strftime to provide a formatted time string. See also time specifiers (p. 170) and timefmt(p. 225).

46

gnuplot 6.0

Timecolumn timecolumn(N,"timeformat") reads string data starting at column N as a time/datevalue and uses "timeformat" to interpret this as "seconds since the epoch" to millisecond precision. If noformat parameter is given, the format defaults to the string from set timefmt. This function is valid onlyin the using specification of a plot or stats command. See plot datafile using (p. 135).
Tm structure Gnuplot stores time internally as a 64-bit floating point value representing seconds since
the epoch date 1 Jan 1970. In order to interpret this as a time or date it is converted to or from a POSIX
standard structure struct tm. Note that fractional seconds, if any, cannot be retrieved via tm sec(). The
components may be accessed individually using the functions• tm hour(t) integer hour in the range 0–23
• tm mday(t) integer day of month in the range 1–31
• tm min(t) integer minute in the range 0–59
• tm mon(t) integer month of year in the range 0–11
• tm sec(t) integer second in the range 0–59
• tm wday(t) integer day of the week in the range 0 (Sunday)–6(Saturday)• tm yday(t) integer day of the year the range 0–365• tm year(t) integer year
Tm week The tm week(t, standard) function interprets its first argument t as a time in seconds from
1 Jan 1970. Despite the name of this function it does not report a field from the POSIX tm structure.
If standard = 0 it returns the week number in the ISO 8601 "week date" system. This corresponds tognuplot’s %W time format. If standard = 1 it returns the CDC epidemiological week number ("epi week").
This corresponds to gnuplot’s %U time format. For corresponding inverse functions that convert week dates
to calendar time see weekdate iso (p. 46), weekdate cdc (p. 47).
In brief, ISO Week 1 of year YYYY begins on the Monday closest to 1 Jan YYYY. This may place it in theprevious calendar year. For example Tue 30 Dec 2008 has ISO week date 2009-W01-2 (2nd day of week 1 of2009). Up to three days at the start of January may come before the Monday of ISO week 1; these days are
assigned to the final week of the previous calendar year. E.g. Fri 1 Jan 2021 has ISO week date 2020-W53-5.
The US Center for Disease Control (CDC) epidemiological week is a similar week date convention that differsfrom the ISO standard by defining a week as starting on Sunday, rather than on Monday.
Weekdate iso

Syntax:time = weekdate_iso( year, week [, day] )This function converts from the year, week, day components of a date in ISO 8601 "week date" format tothe calendar date as a time in seconds since the epoch date 1 Jan 1970. Note that the nominal year in theweek date system is not necessarily the same as the calendar year. The week is an integer from 1 to 53. The
day parameter is optional. If it is omitted or equal to 0 the time returned is the start of the week. Otherwise
day is an integer from 1 (Monday) to 7 (Sunday). See tm week (p. 46) for additional information on an
inverse function that converts from calendar date to week number in the ISO standard convention.
Example:# Plot data from a file with column 1 containing ISO weeks#
Week
cases deaths#
2020-05432
1
calendar_date(w) = weekdate_iso( int(w[1:4]), int(w[6:7]) )set xtics time format "%b\n%Y"plot FILE using (calendar_date(strcol(1))) : 2
title columnheadgnuplot 6.0
Weekdate cdc

47

Syntax:time = weekdate_cdc( year, week [, day] )This function converts from the year, week, day components of a date in the CDC/MMWR "epi week"
format to the calendar date as a time in seconds since the epoch date 1 Jan 1970. The CDC week dateconvention differs from the ISO week date in that it is defined in terms of each week running from day 1 =Sunday to day 7 = Saturday. If the third parameter is 0 or is omitted, the time returned is the start of theweek. See tm week (p. 46) and weekdate iso (p. 46).
Uigammauigamma(a, x) returns the regularized upper incomplete gamma function Q(a, x), NIST DLMF eq 8.2.4
For the complementary lower incomplete gamma function P(a,x), see igamma (p. 44).
Q(a, x) + P(a, x) = 1.
R ∞ a−1 −t
1te dtuigamma(a, z) = Q(a, x) = 1 − P (a, x) = Γ(z)x
The current implementation is from the Cephes library (Moshier 2000). The domain is restricted to reala>0, real x>=0.
Using specifier functions
These functions are valid only in the context of data input. Usually this means use in an expression thatprovides an input field of the using specifier in a plot, splot, fit, or stats command. However the scope ofthe functions is actually the full clause of the plot command, including for example use of columnhead inconstructing the plot title.
Column The column(x) function may be used only in the using specifier of a plot, splot, fit, or stats
command. It evaluates to the numerical value of the content of column x. If the column is expected to holda string, use instead stringcolumn(x) or timecolumn(x, "timeformat"). See plot datafile using (p. 135),
stringcolumn (p. 47), timecolumn (p. 46).
Columnhead The columnhead(x) function may only be used as part of a plot, splot, or stats command.
It evaluates to a string containing the content of column x in the first line of a data file. This is typicallyused to extract the column header for use in a plot title. See plot datafile using (p. 135). Example:
set datafile columnheader
plot for [i=2:4] DATA using 1:i title columnhead(i)Stringcolumn The stringcolumn(x) function may be used only in the using specification of a data plot
or fit command. It returns the content of column x as a string. strcol(x) is shorthand for stringcolumn(x).
If the string is to be interpreted as a time or date, use instead timecolumn(x, "timeformat"). See plot
datafile using (p. 135).
Valid The valid(x) function may be used only in expressions that are part of a using specification. It
can be used to detect explicit NaN values or unexpected garbage in a field of the input stream, perhaps tosubstitute a default value or to prevent further arithmetic operations using NaN. Both "missing" and NaN(not-a-number) data values are considered to be invalid, but it is important to note that if the program
recognizes that a field is truly missing or contains a "missing" flag then the input line is discarded before
the expression invoking valid() would be called. See plot datafile using (p. 135), missing (p. 162).
Example:# Treat an unrecognized bin value as contributing some constant# prior expectation to the bin total rather than ignoring it.
plot DATA using 1 : (valid(2) ? $2 : prior) smooth unique

48

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Value
B = value("A") is effectively the same as B = A, where A is the name of a user-defined variable. This isuseful when the name of the variable is itself held in a string variable. See user-defined variables (p. 52).
It also allows you to read the name of a variable from a data file. If the argument is a numerical expression,value() returns the value of that expression. If the argument is a string that does not correspond to a
currently defined variable, value() returns NaN.
Counting and extracting words
word("string",n) returns the nth word in string. For example, word("one two three",2) returns thestring "two".
words("string") returns the number of words in string. For example, words(" a b c d") returns 4.
Words must be separated by whitespace; if you need to extract individual fields from a string that are
separated by some other character, use instead split.
The word and words functions provide limited support for quoted strings, both single and double quotes
can be used:
print words("\"double quotes\" or 'single quotes'")# 3

A starting quote must either be preceded by a white space, or start the string. This means that apostrophes
in the middle or at the end of words are considered as parts of the respective word:print words("Alexis' phone doesn't work") # 4

Escaping quote characters is not supported. If you want to keep certain quotes, the respective section mustbe surrounded by the other kind of quotes:
s = "Keep \"'single quotes'\" or '\"double quotes\"'"print word(s, 2) # 'single quotes'
print word(s, 4) # "double quotes"

Note, that in this last example the escaped quotes are necessary only for the string definition.
split("string", "sep") uses the character sequence in "sep" as a field separator to split the content of"string" into individual fields. It returns an array of strings, each corresponding to one field of the original
string. The second parameter "sep" is optional. If "sep" is omitted or if it contains a single space characterthe fields are split by any amount of whitespace (space, tab, formfeed, newline, return). Otherwise the fullsequence of characters in "sep" must be matched.
The three examples below each produce an array [ "A", "B", "C", "D" ]t1 = split( "A B C D" )t2 = split( "A B C D", " ")t3 = split( "A;B;C;D", ";")

However the command
t4 = split( "A;B; C;D", "; " )produces an array containing only two strings [ "A;B", "C;D" ] because the two-character field separator
sequence "; " is found only once.
Note: Breaking the string into an array of single characters using an empty string for sep is not currently
implemneted. You can instead accomplish this using single character substrings: Array[i] = "string"[i:i]join(array, "sep") concatenates the string elements of an array into a single string containing fields delimited by the character sequence in "sep". Non-string array elements generate an empty field. The complementary operation split break extracts fields from a string to create an array. Example:
array A = ["A", "B", , 7, "E"]print join(A,";")
A;B;;;Etrim(" padded string ") returns the original string stripped of leading and trailing whitespace. This isuseful for string comparisons of input data fields that may contain extra whitespace. For example
plot FOO using 1:( trim(strcol(3)) eq "A" ? $2 : NaN )gnuplot 6.0

49

Zeta
zeta(s) is the Riemann zeta function with complex domain and range.

−sζ(s) = Σ∞k=1 kThis implementation uses the polynomial series described in algorithm 3 of P. Borwein [2000] CanadianMathematical Society Conference Proceedings. The nominal precision is 1.e-16 over the complex plane.
However note that this does not guarantee that non-trivial zeros of the zeta function will evaluate exactly
to 0.

Operators
The operators in gnuplot are the same as the corresponding operators in the C programming language,
except that all operators accept integer, real, and complex arguments, unless otherwise noted. The **operator (exponentiation) is supported, as in FORTRAN.
Operator precedence is the same as in Fortran and C. As in those languages, parentheses may be used tochange the order of operation. Thus -2**2 = -4, but (-2)**2 = 4.

Unary
The following is a list of all the unary operators:

Symbol+~!
!
$|Unary Operators
Example Explanation-aunary minus+aunary plus (no-operation)~a* one’s complement!a* logical negationa!
* factorial$3* data column in ‘using‘ specifier|A|
cardinality of array A(*) Starred explanations indicate that the operator requires an integer argument.
The factorial operator returns an integer when N! is sufficiently small (N <= 20 for 64-bit integers). It
returns a floating point approximation for larger values of N.
The cardinality operator |...| returns the number of elements |A| in array A. It returns the number of datalines |$DATA| when applied to datablock $DATA.

BinaryThe following is a list of all the binary operators:

50

gnuplot 6.0

Symbol
**
*
/
%
+
==
!=
<
<=
>
>=
<<
>>
&
^
|
&&
||
=
,
.
eq
ne

Binary Operators
Example Explanation
a**b
exponentiation
a*b
multiplication
a/b
division
a%b* modulo
a+b
additiona-b
subtraction
a==bequality
a!=binequality
a<bless thana<=bless than or equal toa>bgreater thana>=bgreater than or equal to0xff<<1 left shift unsigned
0xff>>1 right shift unsigned
a&b* bitwise ANDa^b* bitwise exclusive OR
a|b* bitwise inclusive OR
a&&b* logical AND
a||b* logical ORa = b
assignment(a,b)
serial evaluation
A.B
string concatenation
A eq Bstring equality
A ne Bstring inequality(*) Starred explanations indicate that the operator requires integer arguments. Capital letters A and B
indicate that the operator requires string arguments.
Logical AND (&&) and OR (||) short-circuit the way they do in C. That is, the second && operand is notevaluated if the first is false; the second || operand is not evaluated if the first is true.
Serial evaluation occurs only in parentheses and is guaranteed to proceed in left to right order. The value ofthe rightmost subexpression is returned.
Ternary
There is a single ternary operator:

Symbol?:Ternary Operator
Example Explanationa?b:cternary operation

The ternary operator behaves as it does in C. The first argument (a), which must be an integer, is evaluated.
If it is true (non-zero), the second argument (b) is evaluated and returned; otherwise the third argument (c)is evaluated and returned.
The ternary operator is very useful both in constructing piecewise functions and in plotting points only whencertain conditions are met.
Examples:Plot a function that is to equal sin(x) for 0 <= x < 1, 1/x for 1 <= x < 2, and undefined elsewhere:f(x) = 0<=x && x<1 ? sin(x) : 1<=x && x<2 ? 1/x : 1/0
plot f(x)gnuplot 6.0

51Note that gnuplot quietly ignores undefined values when plotting, so the final branch of the function (1/0)
will produce no plottable points. Note also that f(x) will be plotted as a continuous function across thediscontinuity if a line style is used. To plot it discontinuously, create separate functions for the two pieces.
For data in a file, plot the average of the data in columns 2 and 3 against the datum in column 1, but only
if the datum in column 4 is non-negative:
plot 'file' using 1:( $4<0 ? 1/0 : ($2+$3)/2 )For an explanation of the using syntax, please see plot datafile using (p. 135).

Summation
A summation expression has the formsum [<var> = <start> : <end>] <expression><var> is treated as an integer variable that takes on successive integral values from <start> to <end>. For
each of these, the current value of <expression> is added to a running total whose final value becomes thevalue of the summation expression. Examples:
print sum [i=1:10] i
55.
# Equivalent to plot 'data' using 1:($2+$3+$4+$5+$6+...)
plot 'data' using 1 : (sum [col=2:MAXCOL] column(col))It is not necessary that <expression> contain the variable <var>. Although <start> and <end> can be
specified as variables or expressions, their value cannot be changed dynamically as a side-effect of carryingout the summation. If <end> is less than <start> then the value of the summation is zero.

Gnuplot-defined variables
Gnuplot maintains a number of read-only variables that reflect the current internal state of the program andthe most recent plot. These variables begin with the prefix "GPVAL ". Examples include GPVAL TERM,GPVAL X MIN, GPVAL X MAX, GPVAL Y MIN. Type show variables all to display the complete list
and current values. Values related to axes parameters (ranges, log base) are values used during the last plot,
not those currently set.
Example: To calculate the fractional screen coordinates of the point [X,Y]
GRAPH_X = (X - GPVAL_X_MIN) / (GPVAL_X_MAX - GPVAL_X_MIN)
GRAPH_Y = (Y - GPVAL_Y_MIN) / (GPVAL_Y_MAX - GPVAL_Y_MIN)
SCREEN_X = GPVAL_TERM_XMIN + GRAPH_X * (GPVAL_TERM_XMAX - GPVAL_TERM_XMIN)SCREEN_Y = GPVAL_TERM_YMIN + GRAPH_Y * (GPVAL_TERM_YMAX - GPVAL_TERM_YMIN)FRAC_X = SCREEN_X * GPVAL_TERM_SCALE / GPVAL_TERM_XSIZEFRAC_Y = SCREEN_Y * GPVAL_TERM_SCALE / GPVAL_TERM_YSIZEThe read-only variable GPVAL ERRNO is set to a non-zero value if any gnuplot command terminates early
due to an error. The most recent error message is stored in the string variable GPVAL ERRMSG. BothGPVAL ERRNO and GPVAL ERRMSG can be cleared using the command reset errors.
Interactive terminals with mouse functionality maintain read-only variables with the prefix "MOUSE ".
See mouse variables (p. 62) for details.
The fit mechanism uses several variables with names that begin "FIT ". It is safest to avoid using such
names. When using set fit errorvariables, the error for each fitted parameter will be stored in a variablenamed like the parameter, but with " err" appended. See the documentation on fit (p. 105) and set fit(p. 167) for details.
See user-defined variables (p. 52), reset errors (p. 148), mouse variables (p. 62), and fit (p. 105).

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User-defined variables and functions
New user-defined variables and functions of one through twelve variables may be declared and used anywhere,
including on the plot command itself.
User-defined function syntax:<func-name>( <dummy1> {,<dummy2>} ... {,<dummy12>} ) = <expression>

where <expression> is defined in terms of <dummy1> through <dummy12>. This form of function definition is limited to a single line. More complicated multi-line functions can be defined using the function
block mechanism (new in this version). See function blocks (p. 114).
User-defined variable syntax:<variable-name> = <constant-expression>

Examples:w = 2
q = floor(tan(pi/2 - 0.1))
f(x) = sin(w*x)
sinc(x) = sin(pi*x)/(pi*x)
delta(t) = (t == 0)ramp(t) = (t > 0) ? t : 0min(a,b) = (a < b) ? a : b
comb(n,k) = n!/(k!*(n-k)!)len3d(x,y,z) = sqrt(x*x+y*y+z*z)
plot f(x) = sin(x*a), a = 0.2, f(x), a = 0.4, f(x)file = "mydata.inp"
file(n) = sprintf("run_%d.dat",n)

The final two examples illustrate a user-defined string variable and a user-defined string function.
Note that the variables pi (3.14159...) and NaN (IEEE "Not a Number") are already defined. You canredefine these to something else if you really need to. The original values can be recovered by setting:
NaN = GPVAL_NaN
pi = GPVAL_pi

Other variables may be defined under various gnuplot operations like mousing in interactive terminals or
fitting; see gnuplot-defined variables (p. 51) for details.
You can check for existence of a given variable V by the exists("V") expression. For example
a = 10if (exists("a")) print "a is defined"
if (!exists("b")) print "b is not defined"

Valid names are the same as in most programming languages: they must begin with a letter, but subsequentcharacters may be letters, digits, or " ".
Each function definition is made available as a special string-valued variable with the prefix ’GPFUN ’.
Example:set label GPFUN_sinc at graph .05,.95

See show functions (p. 244), functions (p. 138), gnuplot-defined variables (p. 51), macros (p. 66),
value (p. 48).

ArraysArrays are implemented as indexed lists of user variables. The elements in an array are not limited to asingle type of variable. Arrays must be created explicitly before being referenced. The size of an arraycannot be changed after creation. Array elements are initially undefined unless they are provided in thearray declaragion. In most places an array element can be used instead of a named user variable.
The cardinality (number of elements) of array A is given by the expression |A|.
Examples:gnuplot 6.0

53array A[6]A[1] = 1
A[2] = 2.0
A[3] = {3.0, 3.0}
A[4] = "four"A[6] = A[2]**3
array B[6] = [ 1, 2.0, A[3], "four", , B[2]**3 ]array C = split("A B C D E F")
do for [i=1:6] { print A[i], B[i] }1 1
2.0 2.0{3.0, 3.0} {3.0, 3.0}
four four<undefined> <undefined>
8.0 8.0

Note: Arrays and variables share the same namespace. For example, assignment of a string to a variablenamed FOO will destroy any previously created array with name FOO.
The name of an array can be used in a plot, splot, fit, or stats command. This is equivalent to providing
a file in which column 1 holds the array index (from 1 to size), column 2 holds the value of real(A[i]) andcolumn 3 holds the value of imag(A[i]).
Example:array A[200]do for [i=1:200] { A[i] = sin(i * pi/100.) }plot A title "sin(x) in centiradians"

When plotting the imaginary component of complex array values, it may be referenced either as imag(A[$1])or as $3. These two commands are equivalentplot A using (real(A[$1])) : (imag(A[$1]))
plot A using 2:3

Array functions
Starting with gnuplot version 6, an array can be passed to a function or returned by a function. For example
a simple dot-product function acting on two equal-sized numerical arrays could be defined:
dot(A,B) = (|A| != |B|) ? NaN : sum [i=1:|A|] A[i] * B[i]Built-in functions that return an array include the slice operation array[min:max] and the index retrieval
function index(Array,value).
T = split("A B C D E F")
U = T[3:4]
print T
[ "A", "B", "C", "D", "E", "F" ]print U
[ "C", "D" ]print index( T, "D" )4

Note that T and U in this example are now arrays, whether or not they had been previously declared.
Array indexing
Array indices run from 1 to N for an array with N elements. Element i of array A is accessed by A[i]. The
built-in function index(Array, <value>) returns an integer i such that A[i] is equal to <value>, where<value> may be any expression that evaluates to a number (integer, real, or complex) or a string. The arrayelement must match in both type and value. A return of 0 indicates that no match was found.
array A = [ 4.0, 4, "4" ]print index( A, 4 )2
print index( A, 2.+2. )1
print index( A, "D4"[2:2] )3

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Fonts
Gnuplot does not provide any fonts of its own. It relies on external font handling, the details of which
unfortunately vary from one terminal type to another. Brief documentation of font mechanisms that apply
to more than one terminal type is given here. For information on font use by other individual terminals, see
the documentation for that terminal.
Although it is possible to include non-alphabetic symbols by temporarily switching to a special font, e.g. the
Adobe Symbol font, the preferred method is now to choose UTF-8 encoding and treat the symbol like anyother character. Alternatively you can specify the unicode entry point for the desired symbol as an escapesequence in enhanced text mode. See encoding (p. 166), unicode (p. 35), locale (p. 184), and escapesequences (p. 35).

Cairo (pdfcairo, pngcairo, epscairo, wxt terminals)
Some terminals, including all the cairo-based terminals, access fonts via the fontconfig system library. Please
see the fontconfig user manual.
It is usually sufficient in gnuplot to request a font by a generic name and size, letting fontconfig substitutea similar font if necessary. The following will probably all work:
set term pdfcairo font "sans,12"
set term pdfcairo font "Times,12"
set term pdfcairo font "Times-New-Roman,12"

Gd (png, gif, jpeg, sixel terminals)
Font handling for the png, gif, jpeg, and sixelgd terminals is done by the libgd library. At a minimum it
provides five basic fonts named tiny, small, medium, large, and giant that cannot be scaled or rotated.
Use one of these keywords instead of the font keyword. E.g.
set term png tiny

On many systems libgd can also use generic font handling provided by the fontconfig tools (see fontconfig(p. 54)). On most systems without fontconfig, libgd provides access to Adobe fonts (*.pfa *.pfb) and to
TrueType fonts (*.ttf). You must give the name of the font file, not the name of the font inside it, in theform "<face> {,<size>}". <face> is either the full pathname to the font file, or the first part of a filename
in one of the directories listed in the GDFONTPATH environmental variable. That is, ’set term png font"Face"’ will look for a font file named either <somedirectory>/Face.ttf or <somedirectory>/Face.pfa. For
example, if GDFONTPATH contains /usr/local/fonts/ttf:/usr/local/fonts/pfa then the following pairsof commands are equivalent
set term png font "arial"
set term png font "/usr/local/fonts/ttf/arial.ttf"
set term png font "Helvetica"
set term png font "/usr/local/fonts/pfa/Helvetica.pfa"

To request a default font size at the same time:
set term png font "arial,11"

If no specific font is requested in the "set term" command, gnuplot checks the environmental variable
GNUPLOT DEFAULT GDFONT.

Postscript (also encapsulated postscript *.eps)
PostScript font handling is done by the printer or viewing program. Gnuplot can create valid PostScript or
encapsulated PostScript (*.eps) even if no fonts at all are installed on your computer. Gnuplot simply refers

gnuplot 6.0

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to the font by name in the output file, and assumes that the printer or viewing program will know how tofind or approximate a font by that name.
All PostScript printers or viewers should know about the standard set of Adobe fonts Times-Roman,
Helvetica, Courier, and Symbol. It is likely that many additional fonts are also available, but the specificset depends on your system or printer configuration. Gnuplot does not know or care about this; the output*.ps or *.eps files that it creates will simply refer to whatever font names you request.
Thus
set term postscript eps font "Times-Roman,12"

will produce output that is suitable for all printers and viewers.
On the other hand
set term postscript eps font "Garamond-Premier-Pro-Italic"

will produce a valid PostScript output file, but since it refers to a specialized font only some printers orviewers will be able to display the exact font that was requested. Most will substitute a different font.
However, it is possible to embed a specific font in the output file so that all printers will be able to use it.
This requires that the a suitable font description file is available on your system. Note that some font files
require specific licensing if they are to be embedded in this way. See postscript fontfile (p. 291) for moredetailed description and examples.

Glossary
As gnuplot has evolved over more than 30 years, the meaning of certain words used in commands and in
the documentation may have diverged from current common usage. This section explains how some of theseterms are used in gnuplot.
The term "terminal" refers to an output mode, not to the thing you are typing on. For example, thecommand set terminal pdf means that subsequent plotting commands will produce pdf ouput. Usually
you would want to accompany this with a set output "filename" command to control where the pdf output
is written.
A "page" or "screen" or "canvas" is the entire area addressable by gnuplot. On a desktop it is a full
window; on a plotter, it is a single sheet of paper.
When discussing data files, the term "record" denotes a single line of text in the file, that is, the characters
between newline or end-of-record characters. A "point" is the datum extracted from a single record. A"block" of data is a set of consecutive records delimited by blank lines. A line, when referred to in thecontext of a data file, is a subset of a block. Note that the term "data block" may also be used to refer to a
named block of inline data (see datablocks (p. 55)).

Inline data and datablocks
There are two mechanisms for embedding data into a stream of gnuplot commands. If the special filename’-’ appears in a plot command, then the lines immediately following the plot command are interpreted as
inline data. See special-filenames (p. 134). Data provided in this way can only be used once, by the plot
command it follows.
The second mechanism defines a named data block as a here-document. The named data is persistent andmay be referred to by more than one plot command. Example:$Mydata << EOD
11 22 33 first line of data
44 55 66 second line of data
# comments work just as in a data file
77 88 99

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EOD
stats $Mydata using 1:3
plot $Mydata using 1:3 with points, $Mydata using 1:2 with impulses

Data block names must begin with a $ character, which distinguishes them from other types of persistentvariables. The end-of-data delimiter (EOD in the example) may be any sequence of alphanumeric characters.
For a parallel mechanism that stores executable commands rather than data in a named block, see function
blocks (p. 114).
The storage associated with named data blocks can be released using undefine command. undefine $*frees all named data and function blocks at once.

Iteration
gnuplot supports command iteration and blockstructured if/else/while/do constructs. See if (p. 116),
while (p. 256), and do (p. 104). Simple iteration ispossible inside plot or set commands. See plot for(p. 141). General iteration spanning multiple commands is possible using a block construct as shown below. For a related new feature, see the summation(p. 51) expression type. Here is an example using several of these new syntax features:
set multiplot layout 2,2
fourier(k, x) = sin(3./2*k)/k * 2./3*cos(k*x)
do for [power = 0:3] {TERMS = 10**power
set title sprintf("%g term Fourier series",TERMS)
plot 0.5 + sum [k=1:TERMS] fourier(k,x) notitle}
unset multiplot

1 term Fourier series

10 term Fourier series

100 term Fourier series

1000 term Fourier series

Iteration is controlled by an iteration specifier with syntax
for [<var> in "string of N elements"]orfor [<var> = <start> : <end> { : <increment> }]In the first case <var> is a string variable that successively evaluates to single-word substrings 1 to N of
the string in the iteration specifier. In the second case <start>, <end>, and <increment> are integers or
integer expressions.
The scope of the iteration variable is private to that iteration. See scope (p. 64). You cannot permanently
change the value of the iteration variable inside the iterated clause. If the iteration variable has a value prior
to iteration, that value will be retained or restored at the end of the iteration. For example, the following
commands will print 1 2 3 4 5 6 7 8 9 10 A.
i = "A"do for [i=1:10] { print i; i=10; }print iLinetypes, colors, and styles
In very old gnuplot versions, each terminal type provided a set of distinct "linetypes" that could differ incolor, in thickness, in dot/dash pattern, or in some combination of color and dot/dash. These colors andpatterns were not guaranteed to be consistent across different terminal types although most used the color

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sequence red/green/blue/magenta/cyan/yellow. You can select this old behaviour via the command set
colorsequence classic, but by default gnuplot now uses a terminal-independent sequence of 8 colors.
You can further customize the sequence of linetype properties interactively or in an initialization file. See
set linetype (p. 182). Several sample initialization files are provided in the distribution package.
The current linetype properties for a particular terminal can be previewed by issuing the test command
after setting the terminal type.
Successive functions or datafiles plotted by a single command will be assigned successive linetypes in thecurrent default sequence. You can override this for any individual function, datafile, or plot element bygiving explicit line properties in the plot command.
Examples:plot "foo", "bar"plot sin(x) linetype 4# plot two files using linetypes 1, 2
# use linetype color 4

In general, colors can be specified using named colors, rgb (red, green, blue) components, hsv (hue, saturation, value) components, or a coordinate along the current pm3d palette. The keyword linecolor may be
abbreviated to lc.
Examples:plot sin(x) lc rgb "violet"
plot sin(x) lc rgb "#FF00FF"
plot sin(x) lc palette cb -45
plot sin(x) lc palette frac 0.3# use one of gnuplot's named colors# explicit RGB triple in hexadecimal# whatever color corresponds to -45# in the current cbrange of the palette# fractional value along the paletteSee colorspec (p. 57), show colornames (p. 244), hsv (p. 42), set palette (p. 198), cbrange(p. 243). See also set monochrome (p. 186).
Linetypes also have an associated dot-dash pattern although not all terminal types are capable of using it.
You can specify the dot-dash pattern independent of the line color. See dashtype (p. 59).

Colorspec
Many commands allow you to specify a linetype with an explicit color.
Syntax:... {linecolor | lc} {"colorname" | <colorspec> | <n>}... {textcolor | tc} {<colorspec> | {linetype | lt} <n>}... {fillcolor | fc} {<colorspec> | linetype <n> | linestyle <n>}where <colorspec> has one of the following forms:
rgbcolor "colorname"rgbcolor "0xRRGGBB"
rgbcolor "0xAARRGGBB"
rgbcolor "#RRGGBB"
rgbcolor "#AARRGGBB"
rgbcolor <integer val>
rgbcolor variable
palette frac <val>palette cb <value>
palette z
palette <colormap>
variable
bgnd
black

# e.g. "blue"# string containing hexadecimal constant# string containing hexadecimal constant# string containing hexadecimal in x11 format# string containing hexadecimal in x11 format# integer value representing AARRGGBB# integer value is read from input file# <val> runs from 0 to 1
# <val> lies within cbrange# use named colormap rather than current palette# color index is read from input file# background color

The "<n>" is the linetype number the color of which is used, see test (p. 253).
"colorname" refers to one of the color names built in to gnuplot. For a list of the available names, see show
colornames (p. 244).

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Hexadecimal constants can be given in quotes as "#RRGGBB" or "0xRRGGBB", where RRGGBB represents the red, green, and blue components of the color and must be between 00 and FF. For example,
magenta = full-scale red + full-scale blue could be represented by "0xFF00FF", which is the hexadecimal
representation of (255 << 16) + (0 << 8) + (255).
"#AARRGGBB" represents an RGB color with an alpha channel (transparency) value in the high bits. An
alpha value of 0 represents a fully opaque color; i.e., "#00RRGGBB" is the same as "#RRGGBB". An
alpha value of 255 (FF) represents full transparency.
For a callable function that converts any of these forms to a 32bit integer representation of the color, see
expressions functions rgbcolor (p. 42).
The color palette is a linear gradient of colors that smoothly maps a single numerical value onto a particularcolor. Two such mappings are always in effect. palette frac maps a fractional value between 0 and 1 onto
the full range of the color palette. palette cb maps the range of the color axis onto the same palette. See
set cbrange (p. 243). See also set colorbox (p. 159). You can use either of these to select a constantcolor from the current palette.
"palette z" maps the z value of each plot segment or plot element into the cbrange mapping of the palette.
This allows smoothly-varying color along a 3d line or surface. It also allows coloring 2D plots by palettevalues read from an extra column of data (not all 2D plot styles allow an extra column). There are two
special color specifiers: bgnd for background color and black.
Background color
Most terminals allow you to set an explicit background color for the plot. The special linetype bgnd willdraw in this color, and bgnd is also recognized as a color. Examples:# This will erase a section of the canvas by writing over it in the# background color
set term wxt background rgb "gray75"
set object 1 rectangle from x0,y0 to x1,y1 fillstyle solid fillcolor bgnd
# Draw an "invisible" line at y=0, erasing whatever was underneathplot 0 lt bgnd

Linecolor variable
lc variable tells the program to use the value read from one column of the input data as a linetype index,
and use the color belonging to that linetype. This requires a corresponding additional column in the using
specifier. Text colors can be set similarly using tc variable.
Examples:# Use the third column of data to assign colors to individual points
plot 'data' using 1:2:3 with points lc variable# A single data file may contain multiple sets of data, separated by two# blank lines. Each data set is assigned as index value (see `index`)# that can be retrieved via the `using` specifier `column(-2)`.
# See `pseudocolumns`. This example uses to value in column -2 to# draw each data set in a different line color.
plot 'data' using 1:2:(column(-2)) with lines lc variable

PaletteSyntax... {lc|fc|tc} palette {z}... {lc|fc|tc} palette frac <fraction>... {lc|fc|tc} palette cb <fixed z-value>... fc palette <colormap>

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The palette defines a range of colors with gray values between 0 and 1. palette frac <fraction> selects
the color with gray value <fraction>.
palette cb <z-value> selects the single color whose fractional gray value is (z - cbmin) / (cbmax - cbmin).
palette and palette z both map the z coordinate of the plot element being colored onto the current palette.
If z is outside cbrange it is by default mapped to palette fraction 0 or palette franction 1. If the option set
pm3d noclipcb is set, then quadrangles in a pm3d plot whose z values are out of range will not be drawn
at all.
fillcolor palette <colormap> maps the z coordinate of a plot element onto a previously saved named
colormap instead of using the current palette. See set colormap (p. 155).
If the colormap has a separate range associated with it, that range is used to map z values analogous to theuse of cbrange to map the standard palette. If there is no separate range for this colormap then cbrange isused.
Rgbcolor variable
You can assign a separate color for each data point, line segment, or label in your plot. lc rgbcolor variable
tells the program to read RGB color information for each line in the data file. This requires a corresponding
additional column in the using specifier. The extra column is interpreted as a 24-bit packed RGB triple.
If the value is provided directly in the data file it is easiest to give it as a hexadecimal value (see rgbcolor(p. 42)). Alternatively, the using specifier can contain an expression that evaluates to a 24-bit RGB color
as in the example below. Text colors are similarly set using tc rgbcolor variable.
Example:# Place colored points in 3D at the x,y,z coordinates corresponding to# their red, green, and blue components
rgb(r,g,b) = 65536 * int(r) + 256 * int(g) + int(b)splot "data" using 1:2:3:(rgb($1,$2,$3)) with points lc rgb variable

Dashtype
The dash pattern (dashtype) is a separate property associated with each line, analogous to linecolor or
linewidth. It is not necessary to place the current terminal in a special mode just to draw dashed lines.
I.e. the old command set term <termname> {solid|dashed} is now ignored.
All lines have the property dashtype solid unless you specify otherwise. You can change the default for aparticular linetype using the command set linetype so that it affects all subsequent commands, or you can
include the desired dashtype as part of the plot or other command.
Syntax:
dashtype N
dashtype "pattern"# predefined dashtype invoked by number# string containing a combination of the characters# dot (.) hyphen (-) underscore(_) and space.
dashtype (s1,e1,s2,e2,s3,e3,s4,e4) # dash pattern specified by 1 to 4
# numerical pairs <solid length>, <emptyspace length>

Example:# Two functions using linetype 1 but distinguished by dashtype
plot f1(x) with lines lt 1 dt solid, f2(x) with lines lt 1 dt 3

Some terminals support user-defined dash patterns in addition to whatever set of predefined dash patterns
they offer.
Examples:plot f(x) dt 3
# use terminal-specific dash pattern 3plot f(x) dt ".. "# construct a dash pattern on the spot
plot f(x) dt (2,5,2,15)# numerical representation of the same pattern
set dashtype 11 (2,4,4,7) # define new dashtype to be called by index
plot f(x) dt 11# plot using our new dashtype

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If you specify a dash pattern using a string the program will convert this to a sequence of <solid>,<empty>
pairs. Dot "." becomes (2,5), dash "-" becomes (10,10), underscore " " becomes (20,10), and each spacecharacter " " adds 10 to the previous <empty> value. The command show dashtype will show both theoriginal string and the converted numerical sequence.

Linestyles vs linetypes
A linestyle is a temporary association of properties linecolor, linewidth, dashtype, and pointtype. It isdefined using the command set style line. Once you have defined a linestyle, you can use it in a plot
command to control the appearance of one or more plot elements. In other words, it is just like a linetype
except for its lifetime. Whereas linetypes are permanent (they last until you explicitly redefine them),linestyles last until the next reset of the graphics state.
Examples:# define a new line style with terminal-independent color cyan,# linewidth 3, and associated point type 6 (a circle with a dot in it).
set style line 5 lt rgb "cyan" lw 3 pt 6
plot sin(x) with linespoints ls 5
# user-defined line style 5

Special linetypes
A few special (non-numerical) linetypes are recognized.
lt black specifies a solid black line.
lt bgnd specifies a solid line with the background color of the current terminal. See background (p. 58).
lt nodraw skips drawing the line altogether. This is useful in conjunction with plot style linespoints. It
allows you to suppress the line component of the plot while retaining point properties that are available onlyin this plot style. For example
plot f(x) with linespoints lt nodraw pointinterval -3

will draw only every third point and will isolate it by placing a small circle of background color underneathit. See linespoints (p. 88). lt nodraw may also be used to suppress a particular set of lines that would
otherwise be drawn automatically. For example you could suppress certain contour levels in a contour plotby setting their linetype to nodraw.

LayersA gnuplot plot is built up by drawing its various components in a fixed order. This order can be modified byassigning some components to a specific layer using the keywords behind, back, or front. For example, toreplace the background color of the plot area you could define a colored rectangle with the attribute behind.
set object 1 rectangle from graph 0,0 to graph 1,1 fc rgb "gray" behind

The order of drawing isbehindback
the plot itself
the plot legend (`key`)front

Within each layer elements are drawn in the order
grid, axis, and border elements
pixmaps in numerical orderobjects (rectangles, circles, ellipses, polygons) in numerical orderlabels in numerical order
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61

In the case of multiple plots on a single page (multiplot mode) this order applies separately to each component
plot, not to the multiplot as a whole.
An exception to this is that several TeX-based terminals (e.g. pslatex, cairolatex) accumulate all text
elements in one output stream and graphics in a separate output stream; the text and graphics are then
combined to yield the final figure. In general this leaves each text element either completely behind orcompletely in front of the graphics.

Mouse input
Many terminals allow interaction with the current plot using the mouse. Some also support the definitionof hotkeys to activate pre-defined functions by hitting a single key while the mouse focus is in the active
plot window. It is even possible to combine mouse input with batch command scripts, by invoking thecommand pause mouse and then using the mouse variables returned by mouse clicking as parameters for
subsequent scripted actions. See bind (p. 61) and mouse variables (p. 62). See also the command set
mouse (p. 187).

Bind
Syntax:bind {allwindows} [<key-sequence>] ["<gnuplot commands>"]
bind <key-sequence> ""reset bind

The bind allows defining or redefining a hotkey, i.e. a sequence of gnuplot commands which will be executed
when a certain key or key sequence is pressed while the driver’s window has the input focus. Note that bindis only available if gnuplot was compiled with mouse support and it is used by all mouse-capable terminals.
A user-specified binding supersedes any builtin bindings, except that <space> and ’q’ cannot normally be
rebound. For an exception, see bind space (p. 62).
Mouse button bindings are only active in 2D plots.
You get the list of all hotkeys by typing show bind or bind or by typing the hotkey ’h’ in the graph window.
Key bindings are restored to their default state by reset bind.
Note that multikey-bindings with modifiers must be given in quotes.
Normally hotkeys are only recognized when the currently active plot window has focus. bind allwindows<key> ... (short form: bind all <key> ...) causes the binding for <key> to apply to all gnuplot plot
windows, active or not. In this case gnuplot variable MOUSE KEY WINDOW is set to the ID of theoriginating window, and may be used by the bound command.
Examples:- set bindings:
bind a "replot"bind "ctrl-a" "plot x*x"bind "ctrl-alt-a" 'print "great"'bind Home "set view 60,30; replot"bind all Home 'print "This is window ",MOUSE_KEY_WINDOW'- show bindings:
bind "ctrl-a"bindshow bind# shows the binding for ctrl-a# shows all bindings# show all bindings- remove bindings:
bind "ctrl-alt-a" ""reset bind# removes binding for ctrl-alt-a(note that builtins cannot be removed)# installs default (builtin) bindings

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gnuplot 6.0- bind a key to toggle something:v=0bind "ctrl-r" "v=v+1;if(v%2)set term x11 noraise; else set term x11 raise"

Modifiers (ctrl / alt) are case insensitive, keys not:ctrl-alt-a == CtRl-alT-a
ctrl-alt-a != ctrl-alt-A

List of modifiers (alt == meta):
ctrl, alt, shift (only valid for Button1 Button2 Button3)

List of supported special keys:"BackSpace", "Tab", "Linefeed", "Clear", "Return", "Pause", "Scroll_Lock","Sys_Req", "Escape", "Delete", "Home", "Left", "Up", "Right", "Down","PageUp", "PageDown", "End", "Begin","KP_Space", "KP_Tab", "KP_Enter", "KP_F1", "KP_F2", "KP_F3", "KP_F4","KP_Home", "KP_Left", "KP_Up", "KP_Right", "KP_Down", "KP_PageUp","KP_PageDown", "KP_End", "KP_Begin", "KP_Insert", "KP_Delete", "KP_Equal","KP_Multiply", "KP_Add", "KP_Separator", "KP_Subtract", "KP_Decimal","KP_Divide","KP_1" - "KP_9", "F1" - "F12"

The following are window events rather than actual keys
"Button1" "Button2" "Button3" "Close"

See also help for mouse (p. 187).
Bind space
If gnuplot was built with configuration option –enable-raise-console, then typing <space> in the plot window
raises gnuplot’s command window. Maybe. In practice this is highly system-dependent. This hotkey can bechanged to ctrl-space by starting gnuplot as ’gnuplot -ctrlq’, or by setting the XResource ’gnuplot*ctrlq’.

Mouse variables
When mousing is active, clicking in the active window will set several user variables that can be accessedfrom the gnuplot command line. The coordinates of the mouse at the time of the click are stored in MOUSE X
MOUSE Y MOUSE X2 and MOUSE Y2. The mouse button clicked, and any meta-keys active at that time,
are stored in MOUSE BUTTON MOUSE SHIFT MOUSE ALT and MOUSE CTRL. These variables are
set to undefined at the start of every plot, and only become defined in the event of a mouse click in theactive plot window. To determine from a script if the mouse has been clicked in the active plot window, it
is sufficient to test for any one of these variables being defined.
plot 'something'pause mouseif (exists("MOUSE_BUTTON")) call 'something_else'; \else print "No mouse click."

It is also possible to track keystrokes in the plot window using the mousing code.
plot 'something'pause mouse keypress
print "Keystroke ", MOUSE_KEY, " at ", MOUSE_X, " ", MOUSE_Y

When pause mouse keypress is terminated by a keypress, then MOUSE KEY will contain the ascii
character value of the key that was pressed. MOUSE CHAR will contain the character itself as a string
variable. If the pause command is terminated abnormally (e.g. by ctrl-C or by externally closing the plot
window) then MOUSE KEY will equal -1.
Note that after a zoom by mouse, you can read the new ranges as GPVAL X MIN, GPVAL X MAX,GPVAL Y MIN, and GPVAL Y MAX, see gnuplot-defined variables (p. 51).

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PersistMany gnuplot terminals (aqua, pm, qt, x11, windows, wxt, ...) open separate display windows on the screen
into which plots are drawn. The persist option tells gnuplot to leave these windows open when the main
program exits. It has no effect on non-interactive terminal output. For example if you issue the command
gnuplot -persist -e 'plot sinh(x)'gnuplot will open a display window, draw the plot into it, and then exit, leaving the display window containing
the plot on the screen. You can also specify persist or nopersist when you set a new terminal.
set term qt persist size 700,500

Depending on the terminal type, some mousing operations may still be possible in the persistent window.
However operations like zoom/unzoom that require redrawing the plot are not possible because the main
program has exited. If you want to leave a plot window open and fully mouseable after creating the plot, forexample when running gnuplot from a script file rather than interactively, see pause mouse close (p. 119).

Plotting
There are four gnuplot commands which actually create a plot: plot, splot, replot, and refresh. Other
commands control the layout, style, and content of the plot that will eventually be created. plot generates
2D plots. splot generates 3D plots (actually 2D projections, of course). replot reexecutes the previous
plot or splot command. refresh is similar to replot but it reuses any previously stored data rather thanrereading data from a file or input stream.
Each time you issue one of these four commands it will redraw the screen or generate a new page of output
containing all of the currently defined axes, labels, titles, and all of the various functions or data sources
listed in the original plot command. If instead you need to place several complete plots next to each otheron the same page, e.g. to make a panel of sub-figures or to inset a small plot inside a larger plot, use thecommand set multiplot to suppress generation of a new page for each plot command.
Much of the general information about plotting can be found in the discussion of plot; information specific
to 3D can be found in the splot section.
plot operates in either rectangular or polar coordinates – see set polar (p. 210). splot operates in
Cartesian coordinates, but will accept azimuthal or cylindrical coordinates on input. See set mapping(p. 185). plot also lets you use each of the four borders – x (bottom), x2 (top), y (left) and y2 (right) –as an independent axis. The axes option lets you choose which pair of axes a given function or data set isplotted against. A full complement of set commands exists to give you complete control over the scales andlabeling of each axis. Some commands have the name of an axis built into their names, such as set xlabel.
Other commands have one or more axis names as options, such as set logscale xy. Commands and options
controlling the z axis have no effect on 2D graphs.
splot can plot surfaces and contours in addition to points and/or lines. See set isosamples (p. 174) for
information about defining the grid for a 3D function. See splot datafile (p. 246) for information about
the requisite file structure for 3D data. For contours see set contour (p. 160), set cntrlabel (p. 156),and set cntrparam (p. 157).
In splot, control over the scales and labels of the axes are the same as with plot except that there is also az axis and labeling the x2 and y2 axes is possible only for pseudo-2D plots created using set view map.

Plugins
The set of functions available for plotting or for evaluating expressions can be extended through a pluginmechanism that imports executable functions from a shared library. For example, gnuplot versions through5.4 did not provide
a built-in implementation of the upper incomplete gamma function Q(a,x).
R ∞ a−11te−t dt .
You could define an approximation directly in gnuplot like this:Q(a, x) = Γ(x)x

64

gnuplot 6.0
Q(a,x) = 1. - igamma(a,x)

However this has inherently limited precision as igamma(a,x) approaches 1. If you need a more accurate
implementation, it would be better to provide one via a plugin (see below). Once imported, the function
can be used just as any other built-in or user-defined function in gnuplot. See import (p. 117).
The gnuplot distribution includes source code and instructions for creating a plugin library in the directorydemo/plugin. You can modify the simple example file demo plugin.c by replacing one or more of the
toy example functions with an implementation of the function you are interested in. This could include
invocation of functions from an external mathematical library.
The demo/plugin directory also contains source for a plugin that implements Q(a,x). As noted above, thisplugin allows earlier versions of gnuplot to provide the same function uigamma as version 6.
import Q(a,x) from "uigamma_plugin"uigamma(a,x) = ((x<1 || x<a) ? 1.0-igamma(a,x) : Q(a,x))

Scope of variables
Gnuplot variables are global except in the special cases listed below. There is a single persistent list of active
variables indexed by name. Assignment to a variable creates or replaces an entry in that list. The only way
to remove a variable from that list is the undefine command.
Exception 1: The scope of the variable used in an iteration specifier is private to that iteration. You cannot
permanently change the value of the iteration variable inside the iterated clause. If the iteration variable has
a value prior to iteration, that value will be retained or restored at the end of the iteration. For example,
the following commands will print 1 2 3 4 5 6 7 8 9 10 A.
i = "A"do for [i=1:10] { print i; i=10; }print i

Exception 2: The parameter names used in defining a function are only placeholders for the actual values
that will be provided when the function is called. For example, any current or future values of x and y are
not relevant to the definition shown here, but A must exist as a global variable when the function is later
evaluated:
func(x,y) = A + (x+y)/2.

Exception 3: Variables declared with the local command. The local qualifier (new in version 6) allows
optional declaration of a variable or array whose scope is limited to the execution of the code block in which
it is found. This includes load and call operations, evaluation of a function block, and the code in curly
brackets that follows an if, else, do for, or while condition. If the name of a local variable duplicates thename of a global variable, the global variable is shadowed until exit from the local scope.
EXPERIMENTAL: As currently implemented the scope of a local variable extends into functions called fromthe code block it was declared in; this includes call, load, and function block invocation. This will probably
change in the future so that the scope is strictly confined to the declaring code block.

Start-up (initialization)
When gnuplot is run, it first looks for a system-wide initialization file gnuplotrc. The location ofthis file is determined when the program is built and is reported by show loadpath. The program then looks in the user’s HOME directory for a file called .gnuplot on Unix-like systems or
GNUPLOT.INI on other systems. (OS/2 will look for it in the directory named in the environment
variable GNUPLOT; Windows will use APPDATA). On Unix-like systems gnuplot additionally checks
for the file $XDG CONFIG HOME/gnuplot/gnuplotrc.

gnuplot 6.0

65String constants, string variables, and string functions
In addition to string constants, most gnuplot commands also accept a string variable, a string expression,or a function that returns a string. For example, the following four methods of creating a plot all result inthe same plot title:
four = "4"graph4 = "Title for plot #4"graph(n) = sprintf("Title for plot #%d",n)plot 'data.4' title "Title for plot #4"
plot 'data.4' title graph4
plot 'data.4' title "Title for plot #".four
plot 'data.4' title graph(4)Since integers are promoted to strings when operated on by the string concatenation operator (’.’ character),the following method also works:
N = 4plot 'data.'.N title "Title for plot #".NIn general, elements on the command line will only be evaluated as possible string variables if they are nototherwise recognizable as part of the normal gnuplot syntax. So the following sequence of commands is legal,
although probably should be avoided so as not to cause confusion:plot = "my_datafile.dat"
title = "My Title"
plot plot title title

Substrings
Substrings can be specified by appending a range specifier to any string, string variable, or string-valued
function. The range specifier has the form [begin:end], where begin is the index of the first character of thesubstring and end is the index of the last character of the substring. The first character has index 1. The
begin or end fields may be empty, or contain ’*’, to indicate the true start or end of the original string. Thus
str[:] and str[*:*] both describe the full string str. Example:
eos = strlen(file)if (file[eos-3:*] eq ".dat") {set output file[1:eos-4] . ".png"
plot file}

There is also an equivalent function substr( string, begin, end ).

String operators
Three binary operators require string operands: the string concatenation operator ".", the string equality
operator "eq" and the string inequality operator "ne". The following example will print TRUE.
if ("A"."B" eq "AB") print "TRUE"

String functions
Gnuplot provides several built-in functions that operate on strings. General formatting functions: see gprintf(p. 169) sprintf (p. 41). Time formatting functions: see strftime (p. 41) strptime (p. 41). String
manipulation: see split (p. 48), substr (p. 41) strstrt (p. 41) trim (p. 48) word (p. 48) words(p. 48).

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String encoding
Gnuplot’s built-in string manipulation functions are sensitive to utf-8 encoding (see set encoding (p. 166)).
For example
set encoding utf8
utf8string = "αβγ"
strlen(utf8string) returns 3 (number of characters, not number of bytes)
utf8string[2:2] evaluates to "β"strstrt(utf8string,"β") evaluates to 2

Substitution and Command line macros
When a command line to gnuplot is first read, i.e. before it is interpreted or executed, two forms of lexical
substitution are performed. These are triggered by the presence of text in backquotes (ascii character 96) or
preceded by @ (ascii character 64).

Substitution of system commands in backquotes
Command-line substitution is specified by a system command enclosed in backquotes. This command isspawned and the output it produces replaces the backquoted text on the command line. Exit status of thesystem command is returned in variables GPVAL SYSTEM ERRNO and GPVAL SYSTEM ERRMSG.
Note: Internal carriage-return (’\r’) and newline (’\n’) characters are not stripped from the substituted
string.
Command-line substitution can be used anywhere on the gnuplot command line except inside strings delimited by single quotes.
For example, these will generate labels with the current time and userid:
set label "generated on `date +%Y-%m-%d` by `whoami`" at 1,1
set timestamp "generated on %Y-%m-%d by `whoami`"

This creates an array containing the names of files in the current directory:
FILES = split( "`ls -1`" )Substitution of string variables as macros
The character @ is used to trigger substitution of the current value of a string variable into the commandline. The text in the string variable may contain any number of lexical elements. This allows string variables
to be used as command line macros. Only string constants may be expanded using this mechanism, notstring-valued expressions. For example:
style1 = "lines lt 4 lw 2"style2 = "points lt 3 pt 5 ps 2"
range1 = "using 1:3"
range2 = "using 1:5"
plot "foo" @range1 with @style1, "bar" @range2 with @style2

The line containing @ symbols is expanded on input, so that by the time it is executed the effect is identicalto having typed in fullplot "foo" using 1:3 with lines lt 4 lw 2, \"bar" using 1:5 with points lt 3 pt 5 ps 2

The function exists() may be useful in connection with macro evaluation. The following example checks that
C can safely be expanded as the name of a user-defined variable:
C = "pi"if (exists(C)) print C," = ", @Cgnuplot 6.0

67

Macro expansion does not occur inside either single or double quotes. However macro expansion does occur
inside backquotes.
Macro expansion is handled as the very first thing the interpreter does when looking at a new line ofcommands and is only done once. Therefore, code like the following will execute correctly:
A = "c=1"@A

but this line will not, since the macro is defined on the same line and will not be expanded in timeA = "c=1"; @A# will not expand to c=1

Macro expansion inside a bracketed iteration occurs before the loop is executed; i.e. @A will always act as
the original value of A even if A itself is reassigned inside the loop.
For execution of complete commands the evaluate command may also be handy.

String variables, macros, and command line substitution
The interaction of string variables, backquotes and macro substitution is somewhat complicated. Backquotes
do not block macro substitution, so
filename = "mydata.inp"
lines = ` wc --lines @filename | sed "s/ .*//" `results in the number of lines in mydata.inp being stored in the integer variable lines. And double quotes do
not block backquote substitution, so
mycomputer = "`uname -n`"results in the string returned by the system command uname -n being stored in the string variable mycomputer.
However, macro substitution is not performed inside double quotes, so you cannot define a system command
as a macro and then use both macro and backquote substitution at the same time.
machine_id = "uname -n"
mycomputer = "`@machine_id`"# doesn't work!!

This fails because the double quotes prevent @machine id from being interpreted as a macro. To store asystem command as a macro and execute it later you must instead include the backquotes as part of themacro itself. This is accomplished by defining the macro as shown below. Notice that the sprintf format
nests all three types of quotes.
machine_id = sprintf('"`uname -n`"')mycomputer = @machine_id

SyntaxOptions and any accompanying parameters are separated by spaces whereas lists and coordinates are separated by commas. Ranges are separated by colons and enclosed in brackets [], text and file names are
enclosed in quotes, and a few miscellaneous things are enclosed in parentheses.
Commas are used to separate coordinates on the set commands arrow, key, and label; the list of variables
being fitted (the list after the via keyword on the fit command); lists of discrete contours or the loop
parameters which specify them on the set cntrparam command; the arguments of the set commands
dgrid3d, dummy, isosamples, offsets, origin, samples, size, time, and view; lists of tics or the loop
parameters which specify them; the offsets for titles and axis labels; parametric functions to be used to
calculate the x, y, and z coordinates on the plot, replot and splot commands; and the complete sets of
keywords specifying individual plots (data sets or functions) on the plot, replot and splot commands.

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Parentheses are used to delimit sets of explicit tics (as opposed to loop parameters) and to indicate computations in using specifiers of the fit, plot, replot and splot commands.
(Parentheses and commas are also used as usual in function notation.)
Square brackets are used to delimit ranges given in set, plot or splot commands.
Colons are used to separate extrema in range specifications (whether they are given on set, plot or splot
commands) and to separate entries in the using specifier of the plot, replot, splot and fit commands.
Semicolons are used to separate commands given on a single command line.
Curly braces are used in the syntax for enhanced text mode and to delimit blocks in if/then/else statements.
They are also used to denote complex numbers: {3,2} = 3 + 2i.

Quote marks
Gnuplot uses three forms of quote marks for delimiting text strings, double-quote (ascii 34), single-quote(ascii 39), and backquote (ascii 96).
Filenames may be entered with either single- or double-quotes. In this manual the command examples
generally single-quote filenames and double-quote other string tokens for clarity.
String constants and text strings used for labels, titles, or other plot elements may be enclosed in either
single quotes or double quotes. Further processing of the quoted text depends on the choice of quote marks.
Backslash processing of special characters like \n (newline) and \345 (octal character code) is performed
only for double-quoted strings. In single-quoted strings, backslashes are just ordinary characters. To get asingle-quote (ascii 39) in a single-quoted string, it must be doubled. Thus the strings "d\" s’ b\\" and ’d"s’ ’ b\’ are completely equivalent.
Text justification is the same for each line of a multi-line string. Thus the center-justified string"This is the first line of text.\nThis is the second line."

will produce
This is the first line of text.
This is the second line.

but'This is the first line of text.\nThis is the second line.'

will produce
This is the first line of text.\nThis is the second line.

Enhanced text processing is performed for both double-quoted text and single-quoted text. See enhanced
text (p. 34).
Back-quotes are used to enclose system commands for substitution into the command line. See substitution(p. 66).

Time/Date data
gnuplot supports the use of time and/or date information as input data. This feature is activated by thecommands set xdata time, set ydata time, etc.
Internally all times and dates are converted to the number of seconds from the year 1970. The command
set timefmt defines the default format for all inputs: data files, ranges, tics, label positions – anything that
accepts a time data value defaults to receiving it in this format. Only one default format can be in effect at
a given time. Thus if both x and y data in a file are time/date, by default they are interpreted in the sameformat. However this default can be replaced when reading any particular file or column of input using thetimecolumn function in the corresponding using specifier.

gnuplot 6.0

69

The conversion to and from seconds assumes Universal Time (which is the same as Greenwich Standard
Time). There is no provision for changing the time zone or for daylight savings. If all your data refer to thesame time zone (and are all either daylight or standard) you don’t need to worry about these things. But if
the absolute time is crucial for your application, you’ll need to convert to UT yourself.
Commands like show xrange will re-interpret the integer according to timefmt. If you change timefmt,
and then show the quantity again, it will be displayed in the new timefmt. For that matter, if you reset
the data type flag for that axis (e.g. set xdata), the quantity will be shown in its numerical form.
The commands set format or set tics format define the format that will be used for tic labels, whether
or not input for the specified axis is time/date.
If time/date information is to be plotted from a file, the using option must be used on the plot or splot
command. These commands simply use white space to separate columns, but white space may be embedded
within the time/date string. If you use tabs as a separator, some trial-and-error may be necessary to discover
how your system treats them.
The time function can be used to get the current system time. This value can be converted to a datestring with the strftime function, or it can be used in conjunction with timecolumn to generate relative
time/date plots. The type of the argument determines what is returned. If the argument is an integer, time
returns the current time as an integer, in seconds from 1 Jan 1970. If the argument is real (or complex), theresult is real as well. The precision of the fractional (sub-second) part depends on your operating system.
If the argument is a string, it is assumed to be a format string, and it is passed to strftime to provide aformatted time/date string.
The following example demonstrates time/date plotting.
Suppose the file "data" contains records like
03/21/95 10:00

6.02e23

This file can be plotted by
set xdata time
set timefmt "%m/%d/%y"
set xrange ["03/21/95":"03/22/95"]
set format x "%m/%d"
set timefmt "%m/%d/%y %H:%M"
plot "data" using 1:3

which will produce xtic labels that look like "03/21".
Gnuplot tracks time to millisecond precision. Time formats have been modified to match this. Example:
print the current time to msec precision
print strftime("%H:%M:%.3S %d-%b-%Y",time(0.0))
18:15:04.253 16-Apr-2011

See time specifiers (p. 170), set xtics time (p. 238), set mxtics time (p. 192).

Watchpoints
Support for watchpoints is present only if your copy of gnuplot was built with configuration option –enablewatchpoints. This feature is EXPERIMENTAL [details may change in a subsequent release version].
Syntax:plot FOO watch {x|y|z|F(x,y)} = <value>plot FOO watch mouse
set style watchpoints nolabels
set style watchpoints label <label-properties>
unset style watchpoints
show watchpoints# return to default style# summarizes all watches from previous plot command

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A watchpoint is a target value for the x, y, or z coordinate or for a function f(x,y). Each watchpoint is
attached to a single plot within a plot command. Watchpoints are tracked only for styles with lines andwith linespoints. Every component line segment of that plot is checked against all watchpoints attached
the plot to see whether one or more of the watchpoint targets is satisfied at a point along that line segment.
A list of points that satisfy the the target condition ("hits") is accumulated as the plot is drawn.
For example, if there is a watchpoint with a target y=100, each line segment is checked to see if the ycoordinates of the two endpoints bracket the target y value. If so then some point [x,y] on the line segment
satisfies the target condition y = 100 exactly. This target point is then found by linear interpolation or by
iterative bisection.
Watchpoints within a single plot command are numbered successively. More than one watchpoint per plot
component may be specified. Example:
plot DATA using 1:2 smooth cnormal watch y=0.25 watch y=0.5 watch y=0.75

Watchpoint hits for each target in the previous plot
command are stored in named arrays WATCH n. You
can also display a summary of all watchpoint hits fromthe previous plot command; see show watchpoints(p. 230).
gnuplot> show watchpoints
Plot title:"DATA using 1:2 smooth cnormal"
Watch 1 target y = 0.25
(1 hits)
hit 1
x 49.7 y 0.25
Watch 2 target y = 0.5(1 hits)
hit 1
x 63.1 y 0.5
Watch 3 target y = 0.75
(1 hits)
hit 1
x 67.8 y 0.75

Find quartile values on a ROC curve
1.00
68.3 : 0.75

0.75

63.6 : 0.5

0.50

50.6 : 0.25

0

20

40

60

80

0.25

100

120

0.00

Smoothing: Line segments are checked as they are drawn. For unsmoothed data plots this means a hit foundby interpolation will lie exactly on a line segment connecting two data points. If a data plot is smoothed,hits will lie on a line segment from the smoothed curve. Depending on the quality of the smoothed fit, thismay or may not be more accurate than the hit from the unsmoothed data.
Accuracy: If the line segment was generated from a function plot, the exact value of x such that f(x) = y isfound by iterative bisection. Otherwise the coordinates [x,y] are approximated by linear interpolation along
the line segment.

Watch mouse
Using the current mouse x coordinate as a watch target generates a label that moves along the line of the plot
tracking the horizontal position of the mouse. This allows simultaneous readout of the y values of multiple
plot lines in the same graph. The appearance of the point indicating the current position and of the label
can be modified by set style watchpoint and set style textbox
Example:set style watchpoint labels point pt 6 ps 2 boxstyle 1
set style textbox 1 lw 0.5 opaqueplot for [i=1:N] "file.dat" using 1:(column(i)) watch mouse

Watch labels
By default, labels are always generated for the target "watch mouse". You can turn labels on for other watch
targets using the command set style watchpoint labels. The label text is "x : y", where x and y are thecoordinates of the point, formatted using the current settings for the corresponding axes.
Example:set y2tics format "%.2f°"
set style watchpoint labels point pt 6
plot FOO axes x1y2 watch mousegnuplot 6.0

71Part II

Plotting styles
Many plotting styles are available in gnuplot. They are listed alphabetically below. The commands set styledata and set style function change the default plotting style for subsequent plot and splot commands.
You can also specify the plot style explicitly as part of the plot or splot command. If you want to mix plot
styles within a single plot, you must specify the plot style for each component.
Example:plot 'data' with boxes, sin(x) with lines

Each plot style has its own expected set of data entries in a data file. For example, by default the lines styleexpects either a single column of y values (with implicit x ordering) or a pair of columns with x in the firstand y in the second. For more information on how to fine-tune how columns in a file are interpreted as plot
data, see using (p. 135).

ArrowsThe 2D arrows style draws an arrow with specified length and orientation angle at each point (x,y). Additional input columns may be used to provide variable (per-datapoint) color information or arrow style. It
is identical to the 2D style with vectors except that each arrow head is positioned using length + angle
rather than delta x + delta y. See with vectors (p. 95).
4 columns:

xylengthangle

The keywords with arrows may be followed by inline arrow style properties, a reference to a predefinedarrow style, or arrowstyle variable to load the index of the desired arrow style for each arrow from aseparate column.
length > 0 is interpreted in x-axis coordinates. -1 < length < 0 is interpreted in horizontal graph coordinates; i.e. |length| is a fraction of the total graph width. The program will adjust for differences in x and yscaling or plot aspect ratio so that the visual length is independent of the orientation angle.
angle is always specified in degrees.

Arrowstyle variable
For plot styles with arrows and with vectors, you can provide an extra column of input data that provides
an integer arrow style corresponding to style previously defined using set style arrow.
Example:set style arrow 1 head nofilled linecolor "blue" linewidth 0.5
set style arrow 2 head filled linecolor "red" linewidth 1.0# column 5 is expected to contain either 1 or 2,# determining which of the two previous defined styles to use
plot DATA using 1:2:3:4:5 with arrows arrowstyle variable72

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Bee swarm plots"Bee swarm" plots result from applying jitter to separate overlapping points. A typical use is to compare the
distribution of y values exhibited by two or more categories of points, where the category determines the xcoordinate. See the set jitter (p. 175) command for
how to control the overlap criteria and the displacement
pattern used for jittering. The plots in the figure werecreated by the same plot command but different jittersettings.
set jitter
plot $data using 1:2:1 with points lc variableswarm (default)
45
40
35
30
25
20
15
10
5
0

square
45
40
35
30
25
20
15
10
5
0

A

B

A

B

Boxerrorbars
The boxerrorbars style is only relevant to 2D data plotting. It is a combination of the boxes and yerrorbars styles. It requires 3, 4, or 5 columns of data. An additional (4th, 5th or 6th) input column may be
used to provide variable (per-datapoint) color information (see linecolor (p. 57) and rgbcolor variable(p. 59)).
3 columns:
4 columns:
5 columns:

x
x
x

y
y
y

ydeltaydelta xdelta
ylow yhigh xdelta(xdelta <= 0 means use boxwidth)(xdelta <= 0 means use boxwidth)

The boxwidth will come from the fourth column if they errors are given as "ydelta" or from the fifth column
if they are in the form of "ylow yhigh". If xdelta is zeroor negative, the width of the box is controlled by thevalue previously given for boxwidth. See set boxwidth(p. 154).

with boxerrorbars

A vertical error bar is drawn to represent the y error in
the same way as for the yerrorbars style, either fromy-ydelta to y+ydelta or from ylow to yhigh, depending
on how many data columns are provided. The line styleused for the error bar may be controlled using set bars (p. 166). Otherwise the error bar will match theborder of the box.
DEPRECATED: Old versions of gnuplot treated boxwidth = -2.0 as a special case for four-column datawith y errors in the form "ylow yhigh". In this case boxwidth was adjusted to leave no gap between adjacentboxes. This treatment is retained for backward-compatibility but may be removed in a future version.

Boxes
In 2D plots the boxes style draws a rectangle centered about the given x coordinate that extends from thex axis, i.e. from y=0 not from the graph border, to the given y coordinate. The width of the box can beprovided in an additional input column or controlled by set boxwidth. Otherwise each box extends totouch the adjacent boxes.
In 3D plots the boxes style draws a box centered at the given [x,y] coordinate that extends from the planeat z=0 to the given z coordinate. The width of the box on x can be provided in a separate input column or
via set boxwidth. The depth of the box on y is controlled by set boxdepth. Boxes do not automatically
expand to touch each other.

gnuplot 6.0

73

2D boxes
plot with boxes uses 2 or 3 columns of basic data. Additional input columns may be used to provide
information such as variable line or fill color. See rgbcolor variable (p. 59).
2 columns:
3 columns:

x
x

y
y

x_widthThe width of the box is obtained in one of three ways.
If the input data has a third column, this will be used
to set the box width. Otherwise if a width has been set
using the set boxwidth command, this will be used. Ifneither of these is available, the width of each box will
be calculated so that it touches the adjacent boxes.

with boxes

The box interiors are drawn using the current fillstyle.
Alternatively a fillstyle may be specified in the plot command. See set style fill (p. 217). If no fillcolor is givenin the plot command, the current line color is used.
Examples:To plot a data file with solid filled boxes with a small vertical space separating them (bargraph):
set boxwidth 0.9 relative
set style fill solid 1.0
plot 'file.dat' with boxes

To plot a sine and a cosine curve in pattern-filled boxes style with explicit fill color:
set style fill patternplot sin(x) with boxes fc 'blue', cos(x) with boxes fc 'gold'

The sin plot will use pattern 0; the cos plot will use pattern 1. Any additional plots would cycle throughthe patterns supported by the terminal driver.

3D boxes
splot with boxes requires at least 3 columns of input data. Additional input columns may be used toprovide information such as box width or fill color.
3 columns:
4 columns:
5 columns:

x
x
x

y
y
y

z
z
z

[x_width or color]
x_width color

The last column is used as a color only if the splot command specifies a variable color mode. Examples
splot 'blue_boxes.dat' using 1:2:3 fc "blue"
splot 'rgb_boxes.dat' using 1:2:3:4 fc rgb variablesplot 'category_boxes.dat' using 1:2:3:4:5 lc variable

In the first example all boxes are blue and have the width previously set by set boxwidth. In the second
example the box width is still taken from set boxwidth because the 4th column is interpreted as a 24-bit
RGB color. The third example command reads box width from column 4 and interprets the value in column
5 as an integer linetype from which the color is derived.

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By default boxes have no thickness; they consist of asingle rectangle parallel to the xz plane at the specified
y coordinate. You can change this to a true box withfour sides and a top by setting a non-zero extent on y.
See set boxdepth (p. 154).

Full treatment: 3D boxes with pm3d depth sorting and lighting

30
25
20
15
10
5
0

3D boxes are processed as pm3d quadrangles rather thanas surfaces. Because of this the front/back order of drawing is not affected by set hidden3d. See set pm3d
543
(p. 205). In gnuplot version 6 the edges of the box are
1 2 3 42
5 6 7 81
colored by the border color of the plot’s fill style; this is
9 10
a change from version 5. For best results use a combination of set pm3d depthorder base and set pm3d
lighting.

Boxplot
Boxplots are a common way to represent a statistical distribution of values. Quartile boundaries are determinedsuch that 1/4 of the points have a value equal or lessthan the first quartile boundary, 1/2 of the points havea value equal or less than the second quartile (median)value, etc. A box is drawn around the region between
the first and third quartiles, with a horizontal line at
the median value. Whiskers extend from the box touser-specified limits. Points that lie outside these limits
are drawn individually.

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Examples# Place a boxplot at x coordinate 1.0 representing the y values in column 5plot 'data' using (1.0):5# Same plot but suppress outliers and force the width of the boxplot to 0.3
set style boxplot nooutliers
plot 'data' using (1.0):5:(0.3)

By default only one boxplot is produced that represents all y values from the second column of the using
specification. However, an additional (fourth) column can be added to the specification. If present, thevalues of that column will be interpreted as the discrete levels of a factor variable. As many boxplots will bedrawn as there are levels in the factor variable. The separation between these boxplots is 1.0 by default, but
it can be changed by set style boxplot separation. By default, the value of the factor variable is shown
as a tic label below (or above) each boxplot.
Example# Suppose that column 2 of 'data' contains either "control" or "treatment"# The following example produces two boxplots, one for each level of the# factorplot 'data' using (1.0):5:(0):2

The default width of the box can be set via set boxwidth <width> or may be specified as an optional
3rd column in the using clause of the plot command. The first and third columns (x coordinate and width)
are normally provided as constants rather than as data columns.
By default the whiskers extend from the ends of the box to the most distant point whose y value lies within
1.5 times the interquartile range. By default outliers are drawn as circles (point type 7). The width of thebars at the end of the whiskers may be controlled using set bars (p. 166) or set errorbars (p. 166).
These default properties may be changed using the set style boxplot command. See set style boxplot(p. 216), bars (p. 166), boxwidth (p. 154), fillstyle (p. 217), candlesticks (p. 75).

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Boxxyerror
The boxxyerror plot style is only relevant to 2D dataplotting. It is similar to the xyerrorbars style exceptthat it draws rectangular areas rather than crosses. It
uses either 4 or 6 basic columns of input data. An
additional (5th or 7th) input column may be used toprovide variable (per-datapoint) color information (seelinecolor (p. 57) and rgbcolor variable (p. 59)).
4 columns:
6 columns:

x
x

y
y

xdelta ydelta
xlow xhigh ylow

with boxxyerroryhigh

The box width and height are determined from the x and y errors in the same way as they are for thexyerrorbars style — either from xlow to xhigh and from ylow to yhigh, or from x-xdelta to x+xdelta andfrom y-ydelta to y+ydelta, depending on how many data columns are provided.
The 6 column form of the command provides a convenient way to plot rectangles with arbitrary x and ybounds.
The interior of the boxes is drawn according to the current fillstyle. See set style fill (p. 217) and boxes(p. 72) for details. Alternatively a new fillstyle may be specified in the plot command.

Candlesticks
The candlesticks style can be used for 2D data plottingof financial data or for generating box-and-whisker plotsof statistical data. The symbol is a rectangular box,
centered horizontally at the x coordinate and limited
vertically by the opening and closing prices. A verticalline segment at the x coordinate extends up from the
top of the rectangle to the high price and another down
to the low. The vertical line will be unchanged if the
low and high prices are interchanged.

with candlesticks

Five columns of basic data are required:financial data:whisker plot:

date open
x box_min

low high close
whisker_min whisker_highbox_high

The width of the rectangle can be controlled by the set boxwidth command. For backwards compatibility
with earlier gnuplot versions, when the boxwidth parameter has not been set then the width of the candlestickrectangle is taken from set errorbars <width>.
Alternatively, an explicit width for each box-and-whiskers grouping may be specified in an optional 6th
column of data. The width must be given in the same units as the x coordinate.
An additional (6th, or 7th if the 6th column is used for width data) input column may be used to provide
variable (per-datapoint) color information (see linecolor (p. 57) and rgbcolor variable (p. 59)).
By default the vertical line segments have no crossbars at the top and bottom. If you want crossbars, which
are typically used for box-and-whisker plots, then add the keyword whiskerbars to the plot command. By
default these whiskerbars extend the full horizontal width of the candlestick, but you can modify this byspecifying a fraction of the full width.
The usual convention for financial data is that the rectangle is empty if (open < close) and solid fill if (close< open). This is the behavior you will get if the current fillstyle is set to "empty". See fillstyle (p. 217).
If you set the fillstyle to solid or pattern, then this will be used for all boxes independent of open and close
values. See also set errorbars (p. 166) and financebars (p. 79). See also the candlestick

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and financedemos.
Note: To place additional symbols or lines on a box-and-whisker plot requires additional plot components.
The first example below uses a second component that squashes the candlestick onto a single line placed at
the median value.
# Data columns:X Min 1stQuartile Median 3rdQuartile Max
set errorbars 4.0
set style fill empty
plot 'stat.dat' using 1:3:2:6:5 with candlesticks title 'Quartiles', \''using 1:4:4:4:4 with candlesticks lt -1 notitle# Plot with crossbars on the whiskers, crossbars are 50% of full width
plot 'stat.dat' using 1:3:2:6:5 with candlesticks whiskerbars 0.5

See set boxwidth (p. 154), set errorbars (p. 166), set style fill (p. 217), and boxplot (p. 74).

Circles
The circles style plots a circle with an explicit radius ateach data point. The radius is always interpreted in theunits of the plot’s horizontal axis (x or x2). The scaleon y and the aspect ratio of the plot are both ignored.
If the radius is not given in a separate column for eachpoint it is taken from set style circle. In this case theradius may use graph or screen coordinates.
Many combinations of per-point and previously set properties are possible. For 2D plots these include
using x:yusing x:y:radiususing x:y:color
using x:y:radius:color
using x:y:radius:arc_begin:arc_end
using x:y:radius:arc_begin:arc_end:color

2.5
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-1.0
-2.5 -2.0 -1.5 -1.0 -0.5

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1.5

By default a full circle will be drawn. The result is similar to using a points plot with variable size points
and pointtype 7, except that the circles scale with the x axis range. It is possible to instead plot arc segmentsby specifying a start and end angle (in degrees) in columns 4 and 5.
A per-circle color may be provided in the last column of the using specifier. In this case the plot commandmust include a corresponding variable color term such as lc variable or fillcolor rgb variable.
See set style circle (p. 220), set object circle (p. 195), and set style fill (p. 217).
For 3D plots the using specifier must containsplot DATA using x:y:z:radius:color

where the variable color column is optional.
Examples:# draws circles whose area is proportional to the value in column 3
set style fill transparent solid 0.2 noborderplot 'data' using 1:2:(sqrt($3)) with circles, \'data' using 1:2 with linespoints# draws Pac-men instead of circles
plot 'data' using 1:2:(10):(40):(320) with circles

gnuplot 6.0

77# draw a pie chart with inline data
set xrange [-15:15]
set style fill transparent solid 0.9 noborderplot '-' using 1:2:3:4:5:6 with circles lc var
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Contourfill
Contourfill is a 3D plotting style used to color a pm3d
surface in slices along the z axis. It can be used in 2D
projection (set view map) to create 2D contour plots
with solid color between contour lines. The slice boundaries and the assigned colors are both controlled using
set contourfill (p. 161). See also pm3d (p. 205),
zclip (p. 205).
This style can be combined with set contours to superimpose contour lines that bound the slices. Care must
be taken that the slice boundaries from set contourfill
match the contour bounaries from set cntrparam.
# slice boundaries determined by ztics# coloring set by palette mapping the slice midpoint z value
set pm3d border retrace
set contourfill ztics
set ztics -20, 5, 20
set contour
set cntrparam cubic levels increment -20, 5, 20
set cntrlabel onecolor
set view map
splot g(x,y) with contourfill, g(x,y) with lines nosurface

Dots
The dots style plots a tiny dot at each point; this isuseful for scatter plots with many points. Either 1 or 2
columns of input data are required in 2D. Three columns
are required in 3D.
For some terminals (post, pdf) the size of the dot canbe controlled by changing the linewidth.
1 column
2 columns:
3 columns:

yxx# x is row numberyyz# 3D only (splot)

contourfill + contour lines

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Ellipses
The ellipses style plots an ellipse at each data point.
This style is only relevant for 2D plotting. Each ellipse
is described in terms of its center, major and minor diameters, and the angle between its major diameter andthe x axis.

with ellipses

2 columns: x y
3 columns: x y diam (used for both major and minor axes)
4 columns: x y major_diam minor_diam
5 columns: x y major_diam minor_diam angle

If only two input columns are present, they are taken as the coordinates of the centers, and the ellipses will
be drawn with the default extent (see set style ellipse (p. 220)). The orientation of the ellipse, which isdefined as the angle between the major diameter and the plot’s x axis, is taken from the default ellipse style(see set style ellipse (p. 220)).
If three input columns are provided, the third column is used for both diameters. The orientation angle
defaults to zero.
If four columns are present, they are interpreted as x, y, major diameter, minor diameter. Note that theseare diameters, not radii. If either diameter is negative, both diameters will be taken from the default set by
set style ellipse.
An optional 5th column may specify the orientation angle in degrees. The ellipses will also be drawn with
their default extent if either of the supplied diameters in the 3-4-5 column form is negative.
In all of the above cases, optional variable color data may be given in an additional last (3th, 4th, 5th or6th) column. See colorspec (p. 57).
units keyword: If units xy is included in the plot specification, the major diameter is interpreted in theunits of the plot’s horizontal axis (x or x2) while the minor diameter in that of the vertical axis (y or y2). If
the x and y axis scales are not equal, the major/minor diameter ratio will no longer be correct after rotation.
units xx interprets both diameters in units of the x axis. units yy interprets both diameters in units of
the y axis. In the latter two cases the ellipses will have the correct aspect ratio even if the plot is resized. Ifunits is omitted from the plot command, the setting from set style ellipse will be used.
Example (draws ellipses, cycling through the available line types):
plot 'data' using 1:2:3:4:(0):0 with ellipses

See also set object ellipse (p. 195), set style ellipse (p. 220) and fillstyle (p. 217).

Filledcurves
The filledcurves style is only used for 2D plotting. It
has three variants. The first two variants require eithera single function or two columns (x,y) of input data, andmay be further modified by the options listed below.

30

with filledcurves
above
below
curve 1curve 225
20

Syntax:plot ... with filledcurves [option]

where the option can be one of the following
closed{above|below} x1 x2
betweeny r=<a> xy=<x>,<y>

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The first variant, closed, treats the curve itself as a closed polygon. This is the default if there are twocolumns of input data.

gnuplot 6.0
filledcurves closed

79... just filled closed curve,

The second variant is to fill the area between the curve and a given axis, a horizontal or vertical line, or apoint. This can be further restricted to filling the area above or below the specified line.
filledcurves x1... x1 axis,
filledcurves x2... x2 axis, etc for y1 and y2 axes,
filledcurves y=42... line at y=42, i.e. parallel to x axis,
filledcurves xy=10,20 ... point 10,20 of x1,y1 axes (arc-like shape).
filledcurves above r=1.5 the area of a polar plot outside radius 1.5

3 columns:xy

Ag 108 decay data
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yerrorShaded error region
Monotonic spline through data

Rate

The third variant fills the area between two curves sampled at the same set of x coordinates. It requires threecolumns of input data (x, y1, y2). This is the default if
there are three or more columns of input data. If you
have a y value in column 2 and an associated error value
in column 3 the area of uncertainty can be represented
by shading. See also the similar 3D plot style zerrorfill(p. 100).

0plot $DAT using 1:($2-$3):($2+$3) with filledcurves, \$DAT using 1:2 smooth mcs with lines

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Time (sec)

The above and below options apply both to commands of the form... filledcurves above {x1|x2|y|r}=<val>

and to commands of the form... using 1:2:3 with filledcurves below

In either case the option limits the filled area to one side of the bounding line or curve.
Zooming a filled curve drawn from a datafile may produce empty or incorrect areas because gnuplot isclipping points and lines, and not areas.
If the values <x>, <y>, or <a> are outside the drawing boundary they are moved to the graph boundary.
Then the actual fill area in the case of option xy=<x>,<y> will depend on xrange and yrange.

Fill properties
Plotting with filledcurves can be further customized by giving a fillstyle (solid/transparent/pattern) or afillcolor. If no fillstyle (fs) is given in the plot command then the current default fill style is used. See set
style fill (p. 217). If no fillcolor (fc) is given in the plot command, the current line color is used.
The {{no}border} property of the fillstyle is honored by filledcurves mode closed, the default. It is ignoredby all other filledcurves modes. Example:
plot 'data' with filledcurves fc "cyan" fs solid 0.5 border lc "blue"

Financebars
The financebars style is only relevant for 2D data plotting of financial data. It requires 1 x coordinate(usually a date) and 4 y values (prices).
5 columns:

date

open

low

high

close

An additional (6th) input column may be used to provide variable (per-record) color information (see linecolor (p. 57) and rgbcolor variable (p. 59)).

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The symbol is a vertical line segment, located horizontally at the x coordinate and limited vertically by thehigh and low prices. A horizontal tic on the left marks
the opening price and one on the right marks the closing price. The length of these tics may be changed by
set errorbars. The symbol will be unchanged if thehigh and low prices are interchanged. See set errorbars (p. 166) and candlesticks (p. 75), and also thefinance demo.

with financebars

Fillsteps
plot <data> with fillsteps {above|below} {y=<baseline>}

The fillsteps style is only relevant to 2D plotting. It is
exactly like the style steps except that the area between
the curve and the baseline (default y=0) is filled in thecurrent fill style. The options above and below fill
only the portion to one side of the baseline. Note thatin moving from one data point to the next, both steps
and fillsteps first trace the change in x coordinate andthen the change in y coordinate. See steps (p. 94).

with fillsteps
with steps
data points

Fsteps
The fsteps style is only relevant to 2D plotting. It connects consecutive points with two line segments: the firstfrom (x1,y1) to (x1,y2) and the second from (x1,y2) to(x2,y2). The input column requires are the same as forplot styles lines and points. The difference between
fsteps and steps is that fsteps traces first the change
in y and then the change in x. steps traces first thechange in x and then the change in y.

with fsteps
data points

See also steps demo.

Histeps
The histeps style is only relevant to 2D plotting. It
is intended for plotting histograms. Y-values are assumed to be centered at the x-values; the point at x1 isrepresented as a horizontal line from ((x0+x1)/2,y1) to((x1+x2)/2,y1). The lines representing the end points
are extended so that the step is centered on at x. Adjacent points are connected by a vertical line at their average x, that is, from ((x1+x2)/2,y1) to ((x1+x2)/2,y2).
The input column requires are the same as for plot styleslines and points.

with histeps
data points

If autoscale is in effect, it selects the xrange from the data rather than the steps, so the end points willappear only half as wide as the others. See also steps demo.

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81

Heatmaps
Several of gnuplot’s plot styles can be used to create heat maps. The choice of which style to use is dictatedby the type of data.

Pixel-based heat maps all have the property that eachpixel in the map corresponds exactly to one original data
value. The pixel-based image styles require a regular
rectangular grid of data values; see with image (p. 85).
However it is possible to handle missing grid values (seesparse (p. 248)) and it is also possible to mask out only
a portion of the grid for display (see masking (p. 89)).
Unless there are a large number of grid elements, it isusually good to render each rectangular element separately (with image pixels) so that smoothing or lossy
compression is not applied to the resulting "image".

A polar equivalent to image pixel-based heat maps canbe generated using 2D plot style sectors. Each input
point corresponds to exactly one annular sector of a polar grid, equivalent to a pixel. Unlike the polar gridsurface option described below, any number of individual grid sectors may be provided. This plot style canbe used in either polar or cartesian coordinate plots toplace polar sectors anywhere on the graph. The figure
here shows two halves of a polar heat map displaced
across the origin by +/- ∆x on a cartesian coordinate
plot. See with sectors (p. 93).

If the data points do not constitute a regular rectangular grid, they can often be used to fit a gridded surface
by interpolation or by splines. Alternatively a pointdensity function can be mapped onto a gridded plane orsmooth surface. See set dgrid3d (p. 164). The gridded surface can then be plotted as a pm3d surface (seemasking (p. 89) example). In this case the points on
the heat map do not retain a one-to-one correspondencewith the input data. I.e. the validity of the heat map
represenation is only as good as the gridded approximation. The demo collection has examples of generating
2D heatmaps from a set of points heatmap points.dem

If your copy of gnuplot was built with the –enable-polargrid option, polar coordinate data points can be used togenerate a 2D polar heat map in which each "pixel"
corresponded to a pre-determined range of theta andr. See set polar grid (p. 211) and with surface(p. 94). This process is exactly analogous to the use of
set dgrid3d and with pm3d except that it operates
in 2D polar coordinate space.

2D Heat map from in-line array of values
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Polar heatmap composed of sectors positioned on a cartesian x/y plane
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Cluster of points
defining the mask region

pm3d surface masked byconvex hull of the cluster

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Histograms
The histograms style is only relevant to 2D plotting.
It produces a bar chart from a sequence of parallel data
columns. Each element of the plot command must specify a single input data source (e.g. one column of
the input file), possibly with associated tic values or key titles. Four styles of histogram layout are currently
supported.
set style histogram clustered {gap <gapsize>}
set style histogram errorbars {gap <gapsize>} {<linewidth>}
set style histogram rowstacked
set style histogram columnstacked
set style histogram {title font "name,size" tc <colorspec>}

The default style corresponds to set style histogram clustered gap 2. In this style, each set of parallel
data values is collected into a group of boxes clustered at the x-axis coordinate corresponding to theirsequential position (row #) in the selected datafile columns. Thus if <n> datacolumns are selected, the firstcluster is centered about x=1, and contains <n> boxes whose heights are taken from the first entry in thecorresponding <n> data columns. This is followed by a gap and then a second cluster of boxes centered about
x=2 corresponding to the second entry in the respective data columns, and so on. The default gap width of
2 indicates that the empty space between clusters is equivalent to the width of 2 boxes. All boxes derived
from any one column are given the same fill color and/or pattern; however see the subsection histograms
colors (p. 85).
Each cluster of boxes is derived from a single row of the input data file. It is common in such input files thatthe first element of each row is a label. Labels from this column may be placed along the x-axis underneaththe appropriate cluster of boxes with the xticlabels option to using.
The errorbars style is very similar to the clustered style, except that it requires additional columns of
input for each entry. The first column holds the height (y value) of that box, exactly as for the clusteredstyle.
2 columns:
3 columns:

y yerry ymin ymax

bar extends from y-yerr to y+err
bar extends from ymin to ymax

The appearance of the error bars is controlled by the current value of set errorbars and by the optional<linewidth> specification.
Two styles of stacked histogram are supported, chosen by the command set style histogram{rowstacked|columnstacked}. In these styles the data values from the selected columns are collected
into stacks of boxes. Positive values stack upwards from y=0; negative values stack downwards. Mixed
positive and negative values will produce both an upward stack and a downward stack. The default stacking
mode is rowstacked.
The rowstacked style places a box resting on the x-axis for each data value in the first selected column;
the first data value results in a box a x=1, the second at x=2, and so on. Boxes corresponding to the secondand subsequent data columns are layered on top of these, resulting in a stack of boxes at x=1 representing
the first data value from each column, a stack of boxes at x=2 representing the second data value from eachcolumn, and so on. All boxes derived from any one column are given the same fill color and/or pattern (seeset style fill (p. 217)).
The columnstacked style is similar, except that each stack of boxes is built up from a single data column.
Each data value from the first specified data column yields a box in the stack at x=1, each data value fromthe second specified data column yields a box in the stack at x=2, and so on. In this style the color of eachbox is taken from the row number, rather than the column number, of the corresponding data field.
Box widths may be modified using the set boxwidth command. Box fill styles may be set using the set
style fill command.
Histograms always use the x1 axis, but may use either y1 or y2. If a plot contains both histograms and otherplot styles, the non-histogram plot elements may use either the x1 or the x2 axis.
One additional style option set style histogram nokeyseparators is relevant only to plots that containmultiple histograms. See newhistogram (p. 84) for additional discussion of this case.

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Examples:Suppose that the input file contains data values incolumns 2, 4, 6, ... and error estimates in columns 3,
5, 7, ... This example plots the values in columns 2 and4 as a histogram of clustered boxes (the default style).
Because we use iteration in the plot command, any number of data columns can be handled in a single command.
See plot for (p. 141).
set boxwidth 0.9 relative
set style data histograms
set style histogram cluster
set style fill solid 1.0 border lt -1
plot for [COL=2:4:2] 'file.dat' using COL

9ClassBClassA

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This will produce a plot with clusters of two boxes (vertical bars) centered at each integral value on thex axis. If the first column of the input file contains labels, they may be placed along the x-axis using thevariant commandplot for [COL=2:4:2] 'file.dat' using COL:xticlabels(1)If the file contains both magnitude and range information for each value, then error bars can be added to theplot. The following commands will add error bars extending from (y-<error>) to (y+<error>), capped byhorizontal bar ends drawn the same width as the box
itself. The error bars and bar ends are drawn withlinewidth 2, using the border linetype from the current
fill style.
set errorbars fullwidth
set style fill solid 1 border lt -1
set style histogram errorbars gap 2 lw 2plot for [COL=2:4:2] 'file.dat' using COL:COL+1

10

Histogram with error bars
B
A

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This shows how to plot the same data as a rowstacked histogram. Just to be different, the plot command in
this example lists the separate columns individually rather than using iteration.
set style histogram rowstacked
plot 'file.dat' using 2, '' using 4:xtic(1)This will produce a plot in which each vertical bar corresponds to one row of data. Each vertical bar contains
a stack of two segments, corresponding in height to thevalues found in columns 2 and 4 of the datafile. Finally,1086

the commands
set style histogram columnstacked
plot 'file.dat' using 2, '' using 4

4
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Rowstacked
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gnuplot 6.0

will produce two vertical stacks, one for each columnof data. The stack at x=1 will contain a box for eachentry in column 2 of the datafile. The stack at x=2 willcontain a box for each parallel entry in column 4 of thedatafile.

Columnstacked

18
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Because this interchanges gnuplot’s usual interpretationof input rows and columns, the specification of key titles
and x-axis tic labels must also be modified accordingly.
See the comments given below.

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ClassAClassBset style histogram columnstacked
plot '' u 5:key(1)# uses first column to generate key titles
plot '' u 5 title columnhead # uses first row to generate xtic labels

Note that the two examples just given present exactly the same data values, but in different formats.

Newhistogram
Syntax:
newhistogram {"<title>" {font "name,size"} {tc <colorspec>}}{lt <linetype>} {fs <fillstyle>} {at <x-coord>}More than one set of histograms can appear in a single plot. In this case you can force a gap between them,and a separate label for each set, by using the newhistogram command. For example
set style histogram cluster
plot newhistogram "Set A", 'a' using 1, '' using 2, '' using 3, \newhistogram "Set B", 'b' using 1, '' using 2, '' using 3

The labels "Set A" and "Set B" will appear beneath the respective sets of histograms, under the overall x
axis label.
The newhistogram command can also be used to force histogram coloring to begin with a specific color(linetype). By default colors will continue to increment successively even across histogram boundaries. Hereis an example using the same coloring for multiple histograms
plot newhistogram "Set A" lt 4, 'a' using 1, '' using 2, '' using 3, \newhistogram "Set B" lt 4, 'b' using 1, '' using 2, '' using 3

Similarly you can force the next histogram to begin with a specified fillstyle. If the fillstyle is set to pattern,then the pattern used for filling will be incremented automatically.
Starting a new histogram will normally add a blank entry to the key, so that titles from this set of histogram
components will be separated from those of the previous histogram. This blank line may be undesirable
if the components have no individual titles. It can be suppressed by modifying the style with set stylehistogram nokeyseparators.
The at <x-coord> option sets the x coordinate positionof the following histogram to <x-coord>. For example
set style histogram cluster
set style data histogram
set style fill solid 1.0 border -1
set xtic 1 offset character 0,0.3
plot newhistogram "Set A", \'file.dat' u 1 t 1, '' u 2 t 2, \newhistogram "Set B" at 8, \'file.dat' u 2 t 2, '' u 2 t 2

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will position the second histogram to start at x=8.

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85

Automated iteration over multiple columns
If you want to create a histogram from many columns of data in a single file, it is very convenient to use
the plot iteration feature. See plot for (p. 141). For example, to create stacked histograms of the data incolumns 3 through 8
set style histogram columnstacked
plot for [i=3:8] "datafile" using i title columnhead

Histogram color assignments
The program assigns a color to each component box in a histogram automatically such that equivalent data
values maintain a consistent color wherever they appear in the rows or columns of the histogram. The
colors are taken from successive linetypes, starting either with the next unused linetype or an initial linetypeprovided in a newhistogram element.
In some cases this mechanism fails due to data sources that are not truly parallel (i.e. some files contain
incomplete data). In other cases there may be additional properties of the data that could be visualized
by, say, varying the intensity or saturation of their base color. As an alternative to the automatic color
assignment, you can provide an explicit color value for each data value in a second using column via thelinecolor variable or rgb variable mechanism. See colorspec (p. 57). Depending on the layout of yourdata, the color category might correspond to a row header or a column header or a data column. Note thatyou will probably have to customize the key sample colors to match (see keyentry (p. 177)).
Example: Suppose file 001.dat through file 008.dat contain one column with a category identifier A, B, C,... and a second column with a data value. Not all of the files contain a line for every category, so they are
not truly parallel. The program would be wrong to assign the same color to the value from line N in eachfile. Instead we assign a color based on the category in column 1.
file(i) = sprintf("file_%03d.dat",i)array Category = ["A", "B", "C", "D", "E", "F"]color(c) = index(Category, strcol(c))
set style data histogram
plot for [i=1:8] file(i) using 2:(color(1)) linecolor variable

A more complete example including generation of a custom key is in the demo collection
histogram colors.dem

Image
The image, rgbimage, and rgbalpha plotting styles all project a uniformly sampled grid of data values
onto a plane in either 2D or 3D. The input data may be an actual bitmapped image, perhaps converted froma standard format such as PNG, or a simple array of numerical values. These plot styles are often used to
produce heatmaps. For 2D heatmaps in polar coordinates, see set polar grid (p. 211).
This figure illustrates generation of a heat map from anarray of scalar values. The current palette is used to map
each value onto the color assigned to the corresponding
pixel. See also sparse (p. 248).
plot '-' matrix with image
5 4 3 1 0
2 2 0 0 1
0 0 0 1 0
0 1 2 4 3ee

2D Heat map from in-line array of values
0
0
1
2
3

1

2

3

4

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gnuplot 6.0

Each pixel (data point) of the input 2D image will become a rectangle or parallelepiped in the plot. The coordinates of each data point will determine the centerof the parallelepiped. That is, an M x N set of data
will form an image with M x N pixels. This is different from the pm3d plotting style, where an M x N setof data will form a surface of (M-1) x (N-1) elements.
The scan directions for a binary image data grid can befurther controlled by additional keywords. See binary
keywords flipx (p. 124), keywords center (p. 124),
and keywords rotate (p. 124).
Image data can be scaled to fill a particular rectangle
within a 2D plot coordinate system by specifying the x
and y extent of each pixel. See binary keywords dx(p. 124) and dy (p. 124). To generate the figure at theright, the same input image was placed multiple times,
each with a specified dx, dy, and origin. The input PNG
image of a building is 50x128 pixels. The tall building
was drawn by mapping this using dx=0.5 dy=1.5. The
short building used a mapping dx=0.5 dy=0.35.

RGB image mapped onto a plane in 3D

1.0
0.5
0.0
-0.5
-1.0

0

20

40

60

80

100 120

0

20

40

60

80

120
100

Rescaled image used as plot element
200
150

Building Heights
by Neighborhood

200
150

100

100

50

50

0

0

Downtown
S
NE
Suburbs
The image style handles input pixels containing agrayscale or color palette value. Thus 2D plots (plot command) require 3 columns of data (x,y,value),
while 3D plots (splot command) require 4 columns of data (x,y,z,value).

The rgbimage style handles input pixels that are described by three separate values for the red, green,
and blue components. Thus 5D data (x,y,r,g,b) is needed for plot and 6D data (x,y,z,r,g,b) for splot.
The individual red, green, and blue components are assumed to lie in the range [0:255]. This matches theconvention used in PNG and JPEG files (see binary filetype (p. 123)). However some data files use analternative convention in which RGB components are floating point values in the range [0:1]. To use thergbimage style with such data, first use the command set rgbmax 1.0.
The rgbalpha style handles input pixels that contain alpha channel (transparency) information in addition to
the red, green, and blue components. Thus 6D data (x,y,r,g,b,a) is needed for plot and 7D data (x,y,z,r,g,b,a)for splot. The r, g, b, and alpha components are assumed to lie in the range [0:255]. To plot data for which
RGBA components are floating point values in the range [0:1], first use the command set rgbmax 1.0.
If only a single data column is provided for the color components of either rgbimage or rgbalpha plots, it
is interpreted as containing 32 bit packed ARGB data using the convention that alpha=0 means opaqueand alpha=255 means fully transparent. Note that this is backwards from the alpha convention if alpha issupplied in a separate column, but matches the ARGB packing convention for individual commands to set
color. See colorspec (p. 57).

Transparency
The rgbalpha plotting style assumes that each pixel of input data contains an alpha value in the range[0:255]. A pixel with alpha = 0 is purely transparent and does not alter the underlying contents of the plot.
A pixel with alpha = 255 is purely opaque. All terminal types can handle these two extreme cases. A pixel
with 0 < alpha < 255 is partially transparent. Terminal types that do not support partial transparency willround this value to 0 or 255.

Image pixels
Some terminals use device- or library-specific optimizations to render image data within a rectangular 2D
area. This sometimes produces undesirable output, e.g. inter-pixel smoothing, bad clipping or missing

gnuplot 6.0

87

edges. An example of this is the smoothing applied by web browsers when rendering svg images. The pixels
keyword tells gnuplot to use generic code to render the image pixel-by-pixel. This rendering mode is slower
and may result in larger output files, but should produce a consistent rendered view on all terminals. It may
in particular be preferable for heatmaps with a small number of pixels. Example:
plot 'data' with image pixels

Impulses
The impulses style displays a vertical line from y=0
to the y value of each point (2D) or from z=0 to the z
value of each point (3D). Note that the y or z values may
be negative. Data from additional columns can be used
to control the color of each impulse. To use this styleeffectively in 3D plots, it is useful to choose thick lines(linewidth > 1). This approximates a 3D bar chart.
1 column:
2 columns:
3 columns:

y
x
x

y
y

z

with impulses# line from [x,0] to [x,y] (2D)
# line from [x,y,0] to [x,y,z] (3D)

LabelsThe labels style reads coordinates and text from a data
file and places the text string at the corresponding 2D
or 3D position. 3 or 4 input columns of basic data are
required. Additional input columns may be used to provide properties that vary point by point such as text
rotation angle (keywords rotate variable) or color (seetextcolor variable (p. 58)).

Lille
Arras

AmiensCharleville-Mézières
Laon
Le Havre
RouenBeauvais
Reims
Saint-LôCaen
Metz

Paris

Évreux Pontoise

Brest

BobignyChâlons-en-Champagne
Nanterre
Boulogne-Billancourt
Versailles
Créteil
Bar-le-Duc
Nancy

Saint-Brieuc

Quimper

AlençonÉvry
Chartres Melun

RennesLavalLe Mans
VannesOrléans

Chaumont

NantesNiort
La Rochelle

x
x

y
y

string# 2D version
z string # 3D version

ColmarMulhouse

Dijon
Besançon

Bourges
Nevers

La Roche-sur-Yon Poitiers

ÉpinalVesoulBelfort

Châteauroux

Lons-le-Saunier

Moulins

Mâcon
Bourg-en-Bresse

GuéretAnnecyLimoges
Clermont-FerrandVilleurbanne
Lyon
ChambérySaint-Étienne
Grenoble
Périgueux Tulle

Angoulême

BordeauxAurillac

Le Puy-en-Velay

Valence

PrivasCahors3 columns:
4 columns:

Strasbourg

TroyesAuxerreAngers ToursBlois

Rodez
Agen
MontaubanAlbi
Mont-de-Marsan

Mende

AvignonNîmes

Gap
Digne-les-Bains

Nice
Toulouse Montpellier
Aix-en-Provence

Auch

Pau
TarbesCarcassonne
Foix

Perpignan

Marseille
ToulonBastiaAjaccio

The font, color, rotation angle and other properties of the printed text may be specified as additionalcommand options (see set label (p. 180)). The example below generates a 2D plot with text labels
constructed from the city whose name is taken from column 1 of the input file, and whose geographic
coordinates are in columns 4 and 5. The font size is calculated from the value in column 3, in this case thepopulation.
CityName(String,Size) = sprintf("{/=%d %s}", Scale(Size), String)plot 'cities.dat' using 5:4:(CityName(stringcolumn(1),$3)) with labels

If we did not want to adjust the font size to a different size for each city name, the command would be much
simpler:plot 'cities.dat' using 5:4:1 with labels font "Times,8"If the labels are marked as hypertext then the text only appears if the mouse is hovering over the corresponding anchor point. See hypertext (p. 182). In this case you must enable the label’s point attribute
so that there is a point to act as the hypertext anchor:
plot 'cities.dat' using 5:4:1 with labels hypertext point pt 7

88gnuplot 6.0

The labels style can also be used in place of the points
style when the set of predefined point symbols is notsuitable or not sufficiently flexible. For example, here
we define a set of chosen single-character symbols andassign one of them to each point in a plot based on thevalue in data column 3:

with labels

♡
+

⊙

♠

♠
♢

set encoding utf8
symbol(z) = "•2+⊙♠♣♡♢"[int(z):int(z)]splot 'file' using 1:2:(symbol($3)) with labels

♣
•

+

⊙

□
This example shows use of labels with variable rotation angle in column 4 and textcolor ("tc") in column 5.
Note that variable color is always taken from the last column in the using specifier.
plot $Data using 1:2:3:4:5 with labels tc variable rotate variable

Lines
The lines style connects adjacent points with straightline segments. It may be used in either 2D or 3D plots.
The basic form requires 1, 2, or 3 columns of input data.
Additional input columns may be used to provide information such as variable line color (see rgbcolor variable (p. 59)).

with lines

2D form (no "using" spec)
1 column:
2 columns:yx y# implicit x from row number

3D form (no "using" spec)
1 column:
3 columns:z# implicit x from row, y from index
x y z

See also linetypes (p. 56), linewidth (p. 218), and linestyle (p. 218).

Linespoints
The linespoints style (short form lp) connects adjacentpoints with straight line segments and then goes backto draw a small symbol at each point. Points are drawn
with the default size determined by set pointsize unlessa specific point size is given in the plot command or avariable point size is provided in an additional columnof input data. Additional input columns may also be
used to provide information such as variable line color.
See lines (p. 88) and points (p. 90).

α
α

α

α

α
α

with linespoints
pointinterval -2
with lp pt "α" pi -1

α

α

α

α

α

α

Two keywords control whether or not every point in theplot is marked with a symbol, pointinterval (short form pi) and pointnumber (short form pn).
pi N or pi -N tells gnuplot to only place a symbol on every Nth point. A negative value for N will erase
the portion of line segment that passes underneath the symbol. The size of the erased portion is controlled
by set pointintervalbox.
pn N or pn -N tells gnuplot to label only N of the data points, evenly spaced over the data set. As withpi, a negative value for N will erase the portion of line segment that passes underneath the symbol.

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Masking
The plotting style with mask is used to define a masking region that can be applied to pm3d surfaces or
to images specified later in the same plot or splot command. Input data is interpreted as a stream of [x,y]or [x,y,z] coordinates defining the vertices of one or more polygons. As in plotting style with polygons,
polygons are separated by a blank line. If the mask is part of a 3D (splot) command then a column of z
values is required on input but is currently not used for anything.
If a mask definition is present in the plot command, then any subsequent image or pm3d surface in thesame command can be masked by adding the keyword mask. If no mask has been defined, this keyword isignored.
This example illustrates using the convex hull circumscribing a set of points to mask the corresponding
region of a pm3d surface.
set table $HULL
plot $POINTS using 1:2 convexhull
unset table

Cluster of points
defining the mask region

pm3d surface masked byconvex hull of the cluster

set view map
set multiplot layout 1,2
splot $POINTS using 1:2:3 with pm3d, \$POINTS using 1:2:(0) nogrid with points
splot $HULL using 1:2:(0) with mask, \$POINTS using 1:2:3 mask with pm3d
unset multiplot

The splot command for the first panel renders the unmasked surface created by dgrid3d from the original
points and then the points themselves, in that order. The splot command for the second panel renders themasked surface. Note that definition of the mask must come first (plot with mask), followed by the pm3d
surface it applies to (plot style with pm3d modified by the mask keyword). A more complete version ofthis example is in the demo collection mask pm3d.dem
Although it is not shown here, a single mask can include multiple polygonal regions.
The masking commands are EXPERIMENTAL. Details may change in a future release.

Parallelaxes
Parallel axis plots can highlight correlation in a multidimensional data set. Individual columns of input data
are each associated with a separately scaled vertical axis.
If all columns are drawn from a single file then each lineon the plot represents values from a single row of data inthat file. It is common to use some discrete categorization to assign line colors, allowing visual exploration of
the correlation between this categorization and the axis
dimensions.
Syntax:

600
250

500

200

400

150

15

300

100

10

200

50

5

100

axis 1

axis 2

axis 3

8
7
6
5
4
3
2
1
axis 4

set style data parallelaxes
plot $DATA using col1{:varcol1} {at <xpos>} {<line properties}, \$DATA using col2, ...

The at keyword allows explicit placement of the parallel vertical axes along the x axis as in the example
below. If no explicit x coordinate is provide axis N will be placed at x=N.
array xpos[5] = [1, 5, 6, 7, 11, 12]
plot for [col=1:5] $DATA using col with parallelaxes at xpos[col]By default gnuplot will automatically determine the range and scale of the individual axes from the input
data, but the usual set axis range commands can be used to customize this. See set paxis (p. 203).

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Polar plots
Polar plots are generated by changing the current coordinate system to polar before issuing a plot command. The
option set polar tells gnuplot to interpret input 2D coordinates as <angle>,<radius> rather than <x>,<y>.
Many, but not all, of the 2D plotting styles work in polar mode. The figure shows a combination of plot styleslines and filledcurves. See set polar (p. 210), set
rrange (p. 213), set size square (p. 213), set theta(p. 224), set ttics (p. 227).

bounding radius 2.5
3.+sin(t)*cos(5*t)π/2πPolar heatmaps can be generated using plot style withsurface together with set polar grid.
set size square
set angle degrees
set rtics
set grid polar
set palette cubehelix negative gamma 0.8
set polar grid gauss kdensity scale 35
set polar grid theta [0:190]
plot DATA with surface, DATA with points pt 7

1

2

3

4

0

3π/2

50 100 150 200

PointsThe points style displays a small symbol at each point.
The command set pointsize may be used to change
the default size of all points. The point type defaults tothat of the linetype. See linetypes (p. 56). If no using
spec is found in the plot command, input data columns
are interpreted implicitly in the order x y pointsize
pointtype color as described below.

with points ps variable

The first 8 point types are shared by all terminals. Individual terminals may provide a much larger numberof distinct point types. Use the test command to showwhat is provided by the current terminal settings.
Alternatively any single printable character may be given instead of a numerical point type, as in the example
below. You may use any unicode character as the pointtype (assumes utf8 support). See escape sequences(p. 35). Longer strings may be plotted using plot style labels rather than points.
plot f(x) with points pt "#"plot d(x) with points pt "\U+2299"

Variable point properties
Plot styles that contain a point symbol optionally accept addtional data columns in the using specifier tocontrol the appearance of that point. This is indicated by modifying the keywords pointtype, pointsize,
or linecolor in the plot command with the additional keyword variable rather than providing a number.
Plot style with labels also accepts a variable text rotation angle. Example:# Input data provides [x,y] in columns 1:2# point size is given in column 5# RGB color is given as hexadecimal value in column 4# all points use pointtype 7
plot DATA using 1:2:5:4 with points lc rgb variable ps variable pt 7

gnuplot 6.0

91

If more than one variable property is specified, columns are interpreted in the order below regardless of theorder of keywords in the plot command.
textrotation : pointsize : pointtype : color

Thus in the example above "lc rgb variable" appears first in the plot command but the color is taken fromthe final column (4) given by using. Variable color is always taken from the last additional column. There
are several methods of specifying variable color. See colorspec (p. 57).
Note: for information on user-defined program variables, see variables (p. 52).

Polygons
2D plots:
plot DATA {using 1:2} with polygons

plot with polygons is treated as plot with filledcurves closed except that each polygon’s border isrendered as a closed curve even if its first and last points are not the same. The border line type is takenfrom the fill style. The input data file may contain multiple polygons separated by single blank lines. Eachpolygon can be assigned a separate fill color by providing a third using specifier and the keywords fc variable(value is interpreted as a linetype) or fc rgb variable (value is interpreted as a 24-bit RGB color). Only
the color value from the first vertex of the polygon is used.
3D plots:
splot DATA {using x:y:z} with polygons{fillstyle <fillstyle spec>}{fillcolor <colorspec>}

splot with polygons uses pm3d to render individual triangles, quadrangles, and larger polygons in 3D.
These may be facets of a 3D surface or isolated shapes. The code assumes that the vertices lie in a plane.
Vertices defining individual polygons are read from successive records of the input file. A blank line separates
one polygon from the next.
The fill style and color may be specified in the splot command, otherwise the global fillstyle from set style
fill is used. Due to limitations in the pm3d code, a single border line style from set pm3d border isapplied to all 3D polygons. This restriction may be removed in a later gnuplot version, which will impose a
distinction between the linecolor and fillcolor properties.
Each polygon may be assigned a separate fill color by providing a fourth using specifier and the keywords
fc variable (value is interpreted as a linetype) or fc rgb variable (value is interpreted as a 24-bit RGB
color). Only the color value from the first vertex of the polygon is used.
pm3d sort order and lighting are applied to the faces. It is probably always desirable to use set pm3d
depthorder.
set xyplane at 0
set view equal xyz
unset borderunset tics
set pm3d depth
set pm3d border lc "black" lw 1.5
splot 'icosahedron.dat' with polygons \fs transparent solid 0.8 fc bgnd

Rgbalpha
See image (p. 85).

92

Rgbimage
See image (p. 85).

gnuplot 6.0

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93

Sectors

e
gl

an

_
or

ct

The plot style itself can be used in either cartesian orpolar mode (set polar). The units and interpretation
for the azimuth and the sector angle are controlled using
set angles (p. 149) and set theta (p. 224).

A single annular sector in plot style "with sectors"se

The 2D plotting style with sectors renders one annular segment ("sector") for each line of input data. The
shape of each sector is described by four required data
values. An additional pair of data values can be included
to specify the origin of the annulus this sector is takenfrom. A per-sector color may be provided in an additional column.

corner(azimuth, radius)
annular_width(center_x, center_y)Columns 1 and 2 specify the azimuth (theta) and radius (r) of one corner of the sector.
Columns 3 and 4 specify the angular and radial extents of the sector ("sector angle" and "annular width").
Columns 5 and 6, if present, specify the coordinates of the center of the annulus (default [0,0]). Theinterpretation is [x,y] in cartesian mode and [theta,r] in polar mode.
Syntax:plot DATA {using specifier} {units xy | units xx | units yy}

using specifier
4 columns: azimuth radius sector_angle annular_width
5 columns: azimuth radius sector_angle annular_width color
6 columnd: azimuth radius sector_angle annular_width center_x center_y
7 columns: azimuth radius sector_angle annular_width center_x center_y color

Note that if the x and y axis scales are not equal, the envelope of the full annulus in x/y coordinates willappear as an ellipse rather than a circle. The annulus envelope and thus the apparent sector annular width
can be adjusted to correct for unequal axis scales using the same mechanism as for ellipses. Adding units
xx to the command line causes the sector to be rendered as if the current x axis scale applied equally toboth x and y. Similarly units yy causes the sector to be rendered as if the current y axis scale applied
equally to both x and y. See set isotropic (p. 174), set style ellipse (p. 220).
Plotting with sectors can provide polar coordinate equivalents for the cartesian plot styles boxes (see wind rose
figure), boxxyerror and image pixels (see example inheatmaps (p. 81)). Because sector plots are compatible with cartesian mode plot layout, multiple plots canbe placed at different places on a single graph, which
would not be possible for other polar mode plot styles.

Wind rose(polar coordinate histogram using sectors)

An example of using sectors to create a wind rose inshown here. Other applications include polar heatmaps,
dial charts, pie/donut charts, and annular error boxes
for data points in polar coordinates. Worked examples for all of these are given in the sectors demo.

Spiderplot
Spider plots are essentially parallel axis plots in which the axes are arranged radially rather than vertically.
Such plots are sometimes called radar charts. In gnuplot this requires working within a coordinate systemestablished by the command set spiderplot, analogous to set polar except that the angular coordinate isdetermined implicitly by the parallel axis number. The appearance, labelling, and tic placement of the axes
is controlled by set paxis. Further style choices are controlled using set style spiderplot (p. 221), set
grid (p. 171), and the individual components of the plot command.

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gnuplot 6.0

Because each spider plot corresponds to a row of data rather than a column, it would make no sense to
generate key entry titles in the normal way. Instead, if a plot component contains a title the text is used tolabel the corresponding axis. This overrides any previous set paxis n label "Foo". To place a title in thekey, you can either use a separate keyentry command or extract text from a column in the input file withthe key(column) using specifier. See keyentry (p. 177), using key (p. 138).
In this figure a spiderplot with 5 axes is used to compare multiple entities that are each characterized by
five scores. Each line (row) in $DATA generates a new polygon on the plot.
$DATA << EOD
A
B
C
D
E
F
George 15
75
20
43
90
50
Harriet 40
40
40
60
30
50
EOD
set spiderplot
set style spiderplot fs transparent solid 0.2 borderset for [p=1:5] paxis p range [0:100]
set for [p=2:5] paxis p tics format ""setpaxis 1 tics font ",9"set for [p=1:5] paxis p label sprintf("Score %d",p)set grid spiderplot
plot for [i=1:5] $DATA using i:key(1)Score 1
GeorgeHarriet1008060

Score 540

Score 220

Score 4

Score 3

Newspiderplot
Normally the sequential elements of a plot command with spiderplot each correspond to one vertex of asingle polygon. In order to describe multiple polygons in the same plot command, they must be separated
by newspiderplot. Example:# One polygon with 10 vertices
plot for [i=1:5] 'A' using i, for [j=1:5] 'B' using j# Two polygons with 5 vertices
plot for [i=1:5] 'A' using i, newspiderplot, for [j=1:5] 'B' using j

Steps
The steps style is only relevant to 2D plotting. It connects consecutive points with two line segments: the firstfrom (x1,y1) to (x2,y1) and the second from (x2,y1) to(x2,y2). The input column requires are the same as forplot styles lines and points. The difference between
fsteps and steps is that fsteps traces first the change
in y and then the change in x. steps traces first thechange in x and then the change in y. To fill the area
between the curve and the baseline at y=0, use fillsteps.
See also steps demo.

with fillsteps
with steps
data points

Surface
The plot style with surface has two uses.
In 3D plots, with surface always produces a surface. If a 3D data set is recognizable as a mesh (grid) thenby default the program implicitly treats the plot style with lines as requesting a gridded surface, making
with lines a synonym for with surface. However the command set surface explicit suppresses thistreatment, in which case with surface and with lines become distinct styles that may be used in the sameplot.

gnuplot 6.0

95

If you have points in 3D that are not recognized as a grid, you may be able to fit a suitable grid first. See
set dgrid3d (p. 164).
In 2D polar mode plots, with surface is used to produce a solid fill gridded represention of the data.
Generation of the surface is controlled using the command set polar grid (p. 211).

Vectors
The 2D vectors style draws a vector from (x,y) to(x+xdelta,y+ydelta). The 3D vectors style is similar,
but requires six columns of basic data. In both cases,
an additional input column (5th in 2D, 7th in 3D) may
be used to provide variable (per-datapoint) color information. (see linecolor (p. 57) and rgbcolor variable(p. 59)). A small arrowhead is drawn at the end of each
vector.
4 columns:
6 columns:

x
x

y
y

xdelta ydeltaz xdelta ydelta

3

Vector field F(x,y) = (ky,-kx)

2
1

-3

-2

-1

-1

1

2

3

-2

zdelta-3

The keywords "with vectors" may be followed by inline arrow style properties, by reference to a predefinedarrow style, or by a request to read the index of the desired arrow style for each vector from a separate input
column. See the first three examples below.
Examples:plot ... using 1:2:3:4 with vectors filled heads
plot ... using 1:2:3:4 with vectors arrowstyle 3
plot ... using 1:2:3:4:5 with vectors arrowstyle variablesplot 'file.dat' using 1:2:3:(1):(1):(1) with vectors filled head lw 2

Notes: You cannot mix the arrowstyle keyword with other line style qualifiers in the plot command. An
additional column of color values is required if the arrow style includes lc variable or lc rgb variable.
splot with vectors is supported only for set mapping cartesian. set clip one and set clip two affectvectors drawn in 2D. See set clip (p. 156) and arrowstyle (p. 215).
See also the 2D plot style with arrows (p. 71) that is identical to with vectors (p. 95) except that eacharrow is specified using x:y:length:angle.

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Xerrorbars
The xerrorbars style is only relevant to 2D data plots.
xerrorbars is like points, except that a horizontal error bar is also drawn. At each point (x,y), a line isdrawn from (xlow,y) to (xhigh,y) or from (x-xdelta,y) to(x+xdelta,y), depending on how many data columns areprovided. The appearance of the tic mark at the endsof the bar is controlled by set errorbars. The clearance between the point and the error bars is controlled
by set pointintervalbox. To have the error bars passdirectly through the point with no interruption, use unset pointintervalbox. The basic style requires either
3 or 4 columns:
3 columns:
4 columns:

x
x

y
y

with xerrorbars

xdeltaxlow xhigh

An additional input column (4th or 5th) may be used to provide variable color. This style does not permit
variable point properties.

Xyerrorbars
The xyerrorbars style is only relevant to 2D data plots.
xyerrorbars is like points, except that horizontal andwith xyerrorbars
vertical error bars are also drawn. At each point (x,y),lines are drawn from (x,y-ydelta) to (x,y+ydelta) andfrom (x-xdelta,y) to (x+xdelta,y) or from (x,ylow) to(x,yhigh) and from (xlow,y) to (xhigh,y), depending
upon the number of data columns provided. The appearance of the tic mark at the ends of the bar is controlled by set errorbars. The clearance between the
point and the error bars is controlled by set pointintervalbox. To have the error bars pass directly throughthe point with no interruption, use unset pointintervalbox. Either 4 or 6 input columns are required.
4 columns:
6 columns:

x
x

y
y

xdelta ydelta
xlow xhigh ylow

yhigh

If data are provided in an unsupported mixed form, the using specifier of the plot command should be used
to set up the appropriate form. For example, if the data are of the form (x,y,xdelta,ylow,yhigh), then you
can useplot 'data' using 1:2:($1-$3):($1+$3):4:5 with xyerrorbars

An additional input column (5th or 7th) may be used to provide variable color. This style does not permit
variable point properties.

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Xerrorlines
The xerrorlines style is only relevant to 2D data plots.
xerrorlines is like linespoints, except that a horizontal
error line is also drawn. At each point (x,y), a line isdrawn from (xlow,y) to (xhigh,y) or from (x-xdelta,y) to(x+xdelta,y), depending on how many data columns areprovided. The appearance of the tic mark at the ends ofthe bar is controlled by set errorbars. The basic stylerequires either 3 or 4 columns:
3 columns:
4 columns:

x
x

y
y

with xerrorlines

xdeltaxlow xhigh

An additional input column (4th or 5th) may be used to provide variable color. This style does not permit
variable point properties.

Xyerrorlines
The xyerrorlines style is only relevant to 2D data plots.
xyerrorlines is like linespoints, except that horizontal and vertical error bars are also drawn. At each point(x,y), lines are drawn from (x,y-ydelta) to (x,y+ydelta)
and from (x-xdelta,y) to (x+xdelta,y) or from (x,ylow)
to (x,yhigh) and from (xlow,y) to (xhigh,y), depending
upon the number of data columns provided. The appearance of the tic mark at the ends of the bar is controlled by set errorbars. Either 4 or 6 input columns
are required.
4 columns:
6 columns:

x
x

y
y

xdelta ydelta
xlow xhigh ylow

with xyerrorlines

yhigh

If data are provided in an unsupported mixed form, the using specifier of the plot command should be used
to set up the appropriate form. For example, if the data are of the form (x,y,xdelta,ylow,yhigh), then you
can useplot 'data' using 1:2:($1-$3):($1+$3):4:5 with xyerrorlines

An additional input column (5th or 7th) may be used to provide variable color. This style does not permit
variable point properties.

Yerrorbars

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The yerrorbars (or errorbars) style is only relevant
to 2D data plots. yerrorbars is like points, exceptthat a vertical error bar is also drawn. At each point(x,y), a line is drawn from (x,y-ydelta) to (x,y+ydelta)
or from (x,ylow) to (x,yhigh), depending on how many
data columns are provided. The appearance of the tic
mark at the ends of the bar is controlled by set errorbars. The clearance between the point and the error
bars is controlled by set pointintervalbox. To havethe error bars pass directly through the point with nointerruption, use unset pointintervalbox.
2 columns:
3 columns:
4 columns:

with yerrorbars[implicit x] y ydeltax y ydeltax y ylow yhigh

Additional input columns may be used to provide information such as variable point size, point type, or
color.
See also errorbar demo.

Yerrorlines
The yerrorlines (or errorlines) style is only relevant to
2D data plots. yerrorlines is like linespoints, exceptthat a vertical error line is also drawn. At each point(x,y), a line is drawn from (x,y-ydelta) to (x,y+ydelta)
or from (x,ylow) to (x,yhigh), depending on how many
data columns are provided. The appearance of the tic
mark at the ends of the bar is controlled by set errorbars. Either 3 or 4 input columns are required.
3 columns:
4 columns:

x
x

y
y

with yerrorlines

ydeltaylow yhigh

Additional input columns may be used to provide information such as variable point size, point type, or
color.
See also errorbar demo.

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3D plots
3D plots are generated using the command splot rather than plot. Many of the 2D plot styles (points,
images, impulse, labels, vectors) can also be used in 3D by providing an extra column of data containing z
coordinate. Some plot types (pm3d coloring, surfaces, contours) must be generated using the splot commandeven if only a 2D projection is wanted.

Surface plots
The styles splot with lines and splot with surface
3D surface with projected contours
both generate a surface made from a grid of lines. Solidsurfaces can be generated using the style splot with
pm3d. Usually the surface is displayed at some convenient viewing angle, such that it clearly represents a 3D
surface. See set view (p. 228). In this case the X,
Y, and Z axes are all visible in the plot. The illusionof 3D is enhanced by choosing hidden line removal. See
hidden3d (p. 172). The splot command can also calculate and draw contour lines corresponding to constantZ values. These contour lines may be drawn onto thesurface itself, or projected onto the XY plane. See set contour (p. 160).

2D projection (set view map)
An important special case of the splot command is to
map the Z coordinate onto a 2D surface by projecting theplot along the Z axis onto the xy plane. See set viewmap (p. 228). This plot mode is useful for contour
plots and heat maps. This figure shows contours plotted
once with plot style lines and once with style labels.

projected contours using 'set view map'

-0.2
0

0

Y axis

-0.6
-0.4

0.6

0.4

0.2

-0.2
-0.6
-0.4

-0.8
-0.4

-0.2

0.6
0.4
0.2
0

-0.6
0

PM3D plots
3D surfaces can also be drawn using solid pm3d quadrangles rather than lines. In this case there is no hidden
surface removal, but if the component facets are drawn
back-to-front then a similar effect is achieved. See set
pm3d depthorder (p. 208). While pm3d surfaces are
by default colored using a smooth color palette (see set
palette (p. 198)), it is also possible to specify a solid
color surface or to specify distinct solid colors for the
top and bottom surfaces as in the figure shown here. See
pm3d fillcolor (p. 209). Unlike the line-trimming in
hidden3d mode, pm3d surfaces can be smoothly clippedto the current zrange. See set pm3d clipping (p. 208).

-0.8

0.8
0.2

0.2

0.8

-0.2

X axissplot with pm3d, solid fillcolor

10
5
0
-5
-10
0

2

4

-2

0

2

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Fence plots
fence plot constructed with zerrorfill

Z value

Fence plots combine several 2D plots by aligning their
Y coordinates and separating them from each other by
a displacement along X. Filling the area between a basevalue and each plot’s series of Z values enhances thevisual impact of the alignment on Y and comparison on
Z. There are several ways such plots can be created ingnuplot. The simplest is to use the 5 column variant of
the zerrorfill style. Suppose there are separate curves z= Fi(y) indexed by i. A fence plot is generated by splotwith zerrorfill using input columns

A

B

C

D

E

-0.4

-0.2

0.0

0.2

0.4
alue

Yv

i y z_base z_base Fi(y)Isosurface
This 3D plot style requires a populated voxel grid (seeisosurface generated from voxel data
set vgrid (p. 228), vfill (p. 255)). Linear interpolation of voxel grid values is used to estimate fractional
grid coordinates corresponding to the requested isolevel.
These points are then used to generate a tessellated surface. The facets making up the surface are rendered as
pm3d polygons, so the surface coloring, transparency,
and border properties are controlled by set pm3d. In
general the surface is easier to interpret visually if facets
are given a thin border that is darker than the fill color.
By default the tessellation uses a mixture of quadrangles
and triangles. To use triangle only, see set isosurface (p. 174). Example:
set style fill solid 0.3
set pm3d depthorder border lc "blue" lw 0.2
splot $helix with isosurface level 10 fc "cyan"

Zerrorfill
Syntax:splot DATA using 1:2:3:4[:5] with zerrorfill {fc|fillcolor <colorspec>}{lt|linetype <n>} {<line properties>}

The zerrorfill plot style is similar to one variant of the 2D plot style filledcurves. It fills the area between
two functions or data lines that are sampled at the same x and y points. It requires 4 or 5 input columns:
4 columns:
5 columns:

x
x

y
y

z
z

zdeltazlow zhighgnuplot 6.0
The area between zlow and zhigh is filled and then a line
is drawn through the z values. By default both the line
and the fill area use the same color, but you can change
this in the splot command. The fill area properties arealso affected by the global fill style; see set style fill(p. 217).

101

1000
100

k=5
k=4
k=3
k=2
k=1

10

5
If there are multiple curves in the splot command each410
3
100 200
new curve may occlude all previous curves. To get
2
300 400
500 600 1
proper depth sorting so that curves can only be occluded by curves closer to the viewer, use set pm3d
depthorder base. Unfortunately this causes all the filled areas to be drawn after all of the correspondinglines of z values. In order to see both the lines and the depth-sorted fill areas you probably will need to makethe fill areas partially transparent or use pattern fill rather than solid fill.

The fill area in the first two examples below is the same.
splot 'data' using 1:2:3:4 with zerrorfill fillcolor "grey" lt black
splot 'data' using 1:2:3:($3-$4):($3+$4) with zerrorfill
splot '+' using 1:(const):(func1($1)):(func2($1)) with zerrorfill
splot for [k=1:5] datafile[k] with zerrorfill lt black fc lt (k+1)

This plot style can also be used to create fence plots. See fenceplots (p. 100).

Animation
Any of gnuplot’s interactive terminals (qt win wxt x11 aqua) can be used to display an animation by plotting
successive frames from the command line or from a script.
Several non-mousing terminals also support some form of animation. See term sixelgd (p. 296), term
kittycairo (p. 280).
Two terminals can save an animation to a file for later playback locally or by embedding it a web page. See
term gif animate (p. 277), term webp (p. 302).
Example:unset border; unset tics; unset key; set view equal xyz
set pm3d border linecolor "black"set term webp animate delay 50
set output 'spinning_d20.webp'
do for [ang=1:360:2] {set view 60, ang
splot 'icosahedron.dat' with polygons fc "gold"}
unset output

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Part III

Commands
This section lists the commands acceptable to gnuplot in alphabetical order. Printed versions of thisdocument contain all commands; the text available interactively may not be complete. Indeed, on somesystems there may be no commands at all listed under this heading.
Note that in most cases unambiguous abbreviations for command names and their options are permissible,
i.e., "p f(x) w li" instead of "plot f(x) with lines".
In the syntax descriptions, braces ({}) denote optional arguments and a vertical bar (|) separates mutually
exclusive choices.

Break
The break command is only meaningful inside the bracketed iteration clause of a do or while statement.
It causes the remaining statements inside the bracketed clause to be skipped and iteration is terminated.
Execution resumes at the statement following the closing bracket. See also continue (p. 104).

Cd
The cd command changes the working directory.
Syntax:cd '<directory-name>'

The directory name must be enclosed in quotes.
Examples:cd 'subdir'
cd ".."

It is recommended that Windows users use single-quotes, because backslash [\] has special significance inside
double-quotes and has to be escaped. For example,
cd "c:\newdata"

fails, but
cd 'c:\newdata'
cd "c:\\newdata"

work as expected.

Call
The call command is identical to the load command with one exception: the name of the file being loaded
may be followed by up to nine parameters.
call "inputfile" <param-1> <param-2> <param-3> ... <param-9>

Gnuplot now provides a set of string variables ARG0, ARG1, ..., ARG9 and an integer variable ARGC.
When a call command is executed ARG0 is set to the name of the input file, ARGC is set to the numberof parameters present, and ARG1 to ARG9 are loaded from the parameters that follow it on the commandline. Any existing contents of the ARG variables are saved and restored across a call command.

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103

Because the parameters ARG1 ... ARG9 are stored in ordinary string variables they may be dereferenced
by macro expansion. However in many cases it is more natural to use them as you would any other variable.
In parallel with the string representation of parameters ARG1 ... ARG9, the parameters themselves are
stored in an array ARGV[9]. See ARGV (p. 103).
DEPRECATED: Versions prior to 5.0 performed macro-like substitution of the special tokens $0, $1, ... $9with the literal contents of <param-1> ... That older mechanism is no longer supported.
EXPERIMENTAL: Function blocks (new in this version) provide a more flexible alternative to call. Seefunction blocks (p. 114).

ARGV[ ]
When a gnuplot script is entered via the call command any parameters passed by the caller are available via
two mechanisms. Each parameter is stored as a string in variables ARG1, ARG2, ... ARG9. Each parameteris also stored as one element of the array ARGV[9]. Numerical values are stored as complex variables. Allother values are stored as strings. ARGC holds the number of parameters. Thus after a call
call 'routine_1.gp'

1 pi "title"

The three arguments are available inside routine 1.gp as follows
ARGC = 3
ARG1 = "1"
ARG2 = "3.14159"
ARG3 = "title"

ARGV[1] = 1.0
ARGV[2] = 3.14159265358979...
ARGV[3] = "title"

In this example ARGV[1] and ARGV[2] have the full precision of a floating point variable. ARG2 lost
precision in being stored as a string using format "%g".
ARGC and a corresponding array ARGV[ARGC] are also available to code inside a function block call.
However invocation of a function block does not create string variables ARG1,... .

ExampleCall site
MYFILE = "script1.gp"
FUNC = "sin(x)"call MYFILE FUNC 1.23 "This is a plot title"
Upon entry to the called script
ARG0 holds "script1.gp"
ARG1 holds the string "sin(x)"ARG2 holds the string "1.23"
ARG3 holds the string "This is a plot title"
ARGC is 3
The script itself can now execute
plot @ARG1 with lines title ARG3
print ARG2 * 4.56, @ARG2 * 4.56
print "This plot produced by script ", ARG0

Notice that because ARG1 is a string it must be dereferenced as a macro, but ARG2 may be dereferenced
either as a macro (yielding a numerical constant) or a variable (yielding that same numerical value after
auto-promotion of the string "1.23" to a real).
The same result could be obtained directly from a shell script by invoking gnuplot with the -c command line
option:gnuplot -persist -c "script1.gp" "sin(x)" 1.23 "This is a plot title"

Clear
The clear command erases the current screen or output device as specified by set terminal and set output.
This usually generates a formfeed on hardcopy devices.

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For some terminals clear erases only the portion of the plotting surface defined by set size, so for these it
can be used in conjunction with set multiplot to create an inset.
Example:set multiplot
plot sin(x)set origin 0.5,0.5
set size 0.4,0.4
clear
plot cos(x)unset multiplot

Please see set multiplot (p. 189), set size (p. 213), and set origin (p. 196) for details.

Continue
The continue command is only meaningful inside the bracketed iteration clause of a do or while statement.
It causes the remaining statements inside the bracketed clause to be skipped. Execution resumes at the startof the next iteration (if any remain in the loop condition). See also break (p. 102).

Do
Syntax:do for <iteration-spec> {<commands><commands>}

Execute a sequence of commands multiple times. The commands must be enclosed in curly brackets, andthe opening "{" must be on the same line as the do keyword. This command cannot be used with oldstyle (un-bracketed) if/else statements. See if (p. 116). For examples of iteration specifiers, see iteration(p. 56). Example:
set multiplot layout 2,2
do for [name in "A B C D"] {filename = name . ".dat"
set title sprintf("Condition %s",name)plot filename title name}unset multiplot

See also while (p. 256), continue (p. 104), break (p. 102).

Evaluate
The evaluate command executes gnuplot commands contained in a string or in a function block. Newline
characters are not allowed within the string.
evaluate "commands in a string constant"evaluate string_valued_function( ... arguments ... )evaluate $functionblock( ... arguments ... )This is especially useful for a repetition of similar commands.
Example:set_label(x, y, text) \= sprintf("set label '%s' at %f, %f point pt 5", text, x, y)eval set_label(1., 1., 'one/one')eval set_label(2., 1., 'two/one')eval set_label(1., 2., 'one/two')Please see function blocks (p. 114) and substitution macros (p. 66) for other mechanisms that construct or execute strings containing gnuplot commands.

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105

Exit
exit
exit message "error message text"
exit status <integer error code>

The commands exit and quit, as well as the END-OF-FILE character (usually Ctrl-D) terminate input fromthe current input stream: terminal session, pipe, or file input (pipe). If input streams are nested (inherited
load scripts), then reading will continue in the parent stream. When the top level stream is closed, theprogram itself will exit.
The command exit gnuplot will immediately and unconditionally cause gnuplot to exit even if the input
stream is multiply nested. In this case any open output files may not be completed cleanly. Example of use:bind "ctrl-x" "unset output; exit gnuplot"

The command exit error "error message" simulates a program error. In interactive mode it prints theerror message and returns to the command line, breaking out of all nested loops or calls. In non-interactivemode the program will exit.
When gnuplot exits to the controlling shell, the return value is not usually informative. This variant of thecommand allows you to return a specific value.
exit status <value>

See help for batch/interactive (p. 31) for more details.

Fit
The fit command fits a user-supplied real-valued expression to a set of data points, using the nonlinear
least-squares Marquardt-Levenberg algorithm. There can be up to 12 independent variables, there is always
1 dependent variable, and any number of parameters can be fitted. Optionally, error estimates can be input
for weighting the data points.
The basic use of fit is best explained by a simple example where a set of measured x and y values read froma file are used to be modeled by a function y = f(x).
f(x) = a + b*x + c*x**2
fit f(x) 'measured.dat' using 1:2 via a,b,c
plot 'measured.dat' u 1:2, f(x)Syntax:fit {<ranges>} <expression>'<datafile>' {datafile-modifiers}{{unitweights} | {y|xy|z}error | errors <var1>{,<var2>,...}}
via '<parameter file>' | <var1>{,<var2>,...}

Ranges may be specified to filter the data used in fitting. Out-of-range data points are ignored. The syntax
is[{dummy_variable=}{<min>}{:<max>}],analogous to plot; see plot ranges (p. 139).
<expression> can be any valid gnuplot expression, although the most common is a previously user-defined
function of the form f(x) or f(x,y). It must be real-valued. The names of the independent variables are set
by the set dummy command, or in the <ranges> part of the command (see below); by default, the firsttwo are called x and y. Furthermore, the expression should depend on one or more variables whose value isto be determined by the fitting procedure.
<datafile> is treated as in the plot command. All the plot datafile modifiers (using, every,...) except
smooth are applicable to fit. See plot datafile (p. 124).
The datafile contents can be interpreted flexibly by providing a using qualifier as with plot commands. For
example to generate the independent variable x as the sum of columns 2 and 3, while taking z from column
6 and requesting equal weights:

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gnuplot 6.0
fit ... using ($2+$3):6

In the absence of a using specification, the fit implicitly assumes there is only a single independent variable.
If the file itself, or the using specification, contains only a single column of data, the line number is taken as
the independent variable. If a using specification is given, there can be up to 12 independent variables (andmore if specially configured at compile time).
The unitweights option, which is the default, causes all data points to be weighted equally. This can bechanged by using the errors keyword to read error estimates of one or more of the variables from the data
file. These error estimates are interpreted as the standard deviation s of the corresponding variable value
and used to compute a weight for the datum as 1/s**2.
In case of error estimates of the independent variables, these weights are further multiplied by fitting function
derivatives according to the "effective variance method" (Jay Orear, Am. J. Phys., Vol. 50, 1982).
The errors keyword is to be followed by a comma-separated list of one or more variable names for which
errors are to be input; the dependent variable z must always be among them, while independent variables
are optional. For each variable in this list, an additional column will be read from the file, containing thatvariable’s error estimate. Again, flexible interpretation is possible by providing the using qualifier. Notethat the number of independent variables is thus implicitly given by the total number of columns in theusing qualifier, minus 1 (for the dependent variable), minus the number of variables in the errors qualifier.
As an example, if one has 2 independent variables, and errors for the first independent variable and thedependent variable, one uses the errors x,z qualifier, and a using qualifier with 5 columns, which areinterpreted as x:y:z:sx:sz (where x and y are the independent variables, z the dependent variable, and sx andsz the standard deviations of x and z).
A few shorthands for the errors qualifier are available: yerrors (for fits with 1 column of independent
variable), and zerrors (for the general case) are all equivalent to errors z, indicating that there is a single
extra column with errors of the dependent variable.
xyerrors, for the case of 1 independent variable, indicates that there are two extra columns, with errors ofboth the independent and the dependent variable. In this case the errors on x and y are treated by Orear’s
effective variance method.
Note that yerror and xyerror are similar in both form and interpretation to the yerrorlines and xyerrorlines 2D plot styles.
With the command set fit v4 the fit command syntax is compatible with gnuplot version 4. In this casethere must be two more using qualifiers (z and s) than there are independent variables, unless there is only
one variable. gnuplot then uses the following formats, depending on the number of columns given in theusing specification:
z
x:z
x:z:s
x:y:z:sx1:x2:x3:z:s
x1:x2:x3:...:xN:z:s# 1 independent variable (line number)# 1 independent variable (1st column)# 1 independent variable (3 columns total)# 2 independent variables (4 columns total)# 3 independent variables (5 columns total)# N independent variables (N+2 columns total)

Please beware that this means that you have to supply z-errors s in a fit with two or more independent
variables. If you want unit weights you need to supply them explicitly by using e.g. then format x:y:z:(1).
The dummy variable names may be changed when specifying a range as noted above. The first range
corresponds to the first using spec, and so on. A range may also be given for z (the dependent variable),in which case data points for which f(x,...) is out of the z range will not contribute to the residual being
minimized.
Multiple datasets may be simultaneously fit with functions of one independent variable by making y a’pseudo-variable’, e.g., the dataline number, and fitting as two independent variables. See fit multi-branch(p. 111).
The via qualifier specifies which parameters are to be optimized, either directly, or by referencing a parameter
file.

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107

Examples:f(x) = a*x**2 + b*x + cg(x,y) = a*x**2 + b*y**2 + c*x*y
set fit limit 1e-6
fit f(x) 'measured.dat' via 'start.par'fit f(x) 'measured.dat' using 3:($7-5) via 'start.par'fit f(x) './data/trash.dat' using 1:2:3 yerror via a, b, c
fit g(x,y) 'surface.dat' using 1:2:3 via a, b, c
fit a0 + a1*x/(1 + a2*x/(1 + a3*x)) 'measured.dat' via a0,a1,a2,a3
fit a*x + b*y 'surface.dat' using 1:2:3 via a,b
fit [*:*][yaks=*:*] a*x+b*yaks 'surface.dat' u 1:2:3 via a,b
fit [][][t=*:*] a*x + b*y + c*t 'foo.dat' using 1:2:3:4 via a,b,c
set dummy x1, x2, x3, x4, x5
h(x1,x2,x3,x4,s5) = a*x1 + b*x2 + c*x3 + d*x4 + e*x5
fit h(x1,x2,x3,x4,x5) 'foo.dat' using 1:2:3:4:5:6 via a,b,c,d,e

After each iteration step, detailed information about the current state of the fit is written to the display.
The same information about the initial and final states is written to a log file, "fit.log". This file is always
appended to, so as to not lose any previous fit history; it should be deleted or renamed as desired. By using
the command set fit logfile, the name of the log file can be changed.
If activated by using set fit errorvariables, the error for each fitted parameter will be stored in a variablenamed like the parameter, but with " err" appended. Thus the errors can be used as input for further
computations.
If set fit prescale is activated, fit parameters are prescaled by their initial values. This helps the MarquardtLevenberg routine converge more quickly and reliably in cases where parameters differ in size by several ordersof magnitude.
The fit may be interrupted by pressing Ctrl-C (Ctrl-Break in wgnuplot). After the current iteration completes, you have the option to (1) stop the fit and accept the current parameter values, (2) continue the fit,(3) execute a gnuplot command as specified by set fit script or the environment variable FIT SCRIPT.
The default is replot, so if you had previously plotted both the data and the fitting function in one graph,
you can display the current state of the fit.
Once fit has finished, the save fit command may be used to store final values in a file for subsequent use asa parameter file. See save fit (p. 148) for details.

Adjustable parameters
There are two ways that via can specify the parameters to be adjusted, either directly on the command line
or indirectly, by referencing a parameter file. The two use different means to set initial values.
Adjustable parameters can be specified by a comma-separated list of variable names after the via keyword.
Any variable that is not already defined is created with an initial value of 1.0. However, the fit is more likely
to converge rapidly if the variables have been previously declared with more appropriate starting values.
In a parameter file, each parameter to be varied and a corresponding initial value are specified, one per line,in the form
varname = value

Comments, marked by ’#’, and blank lines are permissible. The special form
varname = value# FIXEDmeans that the variable is treated as a ’fixed parameter’, initialized by the parameter file, but not adjusted byfit. For clarity, it may be useful to designate variables as fixed parameters so that their values are reported
by fit. The keyword # FIXED has to appear in exactly this form.

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Short introduction
fit is used to find a set of parameters that ’best’ fits your data to your user-defined function. The fit is judged
on the basis of the sum of the squared differences or ’residuals’ (SSR) between the input data points andthe function values, evaluated at the same places. This quantity is often called ’chisquare’ (i.e., the Greek
letter chi, to the power of 2). The algorithm attempts to minimize SSR, or more precisely the weighted sumof squared residuals (WSSR), for which the residuals are weighted by the input data errors before beingsquared; see fit error estimates (p. 108) for details.
That’s why it is called ’least-squares fitting’. Let’s look at an example to see what is meant by ’non-linear’,but first we had better go over some terms. Here it is convenient to use z as the dependent variable foruser-defined functions of either one independent variable, z=f(x), or two independent variables, z=f(x,y). A
parameter is a user-defined variable that fit will adjust, i.e., an unknown quantity in the function declaration.
Linearity/non-linearity refers to the relationship of the dependent variable, z, to the parameters which fit
is adjusting, not of z to the independent variables, x and/or y. (To be technical, the second {and higher}
derivatives of the fitting function with respect to the parameters are zero for a linear least-squares problem).
For linear least-squares the user-defined function will be a sum of simple functions, not involving any parameters, each multiplied by one parameter. Nonlinear least-squares handles more complicated functions inwhich parameters can be used in a large number of ways. An example that illustrates the difference between
linear and nonlinear least-squares is the Fourier series. One member may be written as
z=a*sin(c*x) + b*cos(c*x).

If a and b are the unknown parameters and c is constant, then estimating values of the parameters is a linear
least-squares problem. However, if c is an unknown parameter, the problem is nonlinear.
In the linear case, parameter values can be determined by comparatively simple linear algebra, in one
direct step. However the linear special case is also solved along with more general nonlinear problems by
the iterative procedure that gnuplot uses. fit attempts to find the minimum by doing a search. Eachstep (iteration) calculates WSSR with a new set of parameter values. The Marquardt-Levenberg algorithm
selects the parameter values for the next iteration. The process continues until a preset criterion is met,
either (1) the fit has "converged" (the relative change in WSSR is less than a certain limit, see set fit
limit (p. 167)), or (2) it reaches a preset iteration count limit (see set fit maxiter (p. 167)). The fit
may also be interrupted and subsequently halted from the keyboard (see fit (p. 105)). The user variable
FIT CONVERGED contains 1 if the previous fit command terminated due to convergence; it contains 0 if
the previous fit terminated for any other reason. FIT NITER contains the number of iterations that weredone during the last fit.
Often the function to be fitted will be based on a model (or theory) that attempts to describe or predict
the behaviour of the data. Then fit can be used to find values for the free parameters of the model, todetermine how well the data fits the model, and to estimate an error range for each parameter. See fit
error estimates (p. 108).
Alternatively, in curve-fitting, functions are selected independent of a model (on the basis of experience as
to which are likely to describe the trend of the data with the desired resolution and a minimum number ofparameters*functions.) The fit solution then provides an analytic representation of the curve.
However, if all you really want is a smooth curve through your data points, the smooth option to plot may
be what you’ve been looking for rather than fit.

Error estimates
In fit, the term "error" is used in two different contexts, data error estimates and parameter error estimates.
Data error estimates are used to calculate the relative weight of each data point when determining theweighted sum of squared residuals, WSSR or chisquare. They can affect the parameter estimates, since they
determine how much influence the deviation of each data point from the fitted function has on the final
values. Some of the fit output information, including the parameter error estimates, is more meaningful if
accurate data error estimates have been provided.

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The statistical overview describes some of the fit output and gives some background for the ’practicalguidelines’.
Statistical overview
The theory of non-linear least-squares is generally described in terms of a normal distribution of errors, thatis, the input data is assumed to be a sample from a population having a given mean and a Gaussian (normal)
distribution about the mean with a given standard deviation. For a sample of sufficiently large size, andknowing the population standard deviation, one can use the statistics of the chisquare distribution to describea "goodness of fit" by looking at the variable often called "chisquare". Here, it is sufficient to say that a
reduced chisquare (chisquare/degrees of freedom, where degrees of freedom is the number of datapoints lessthe number of parameters being fitted) of 1.0 is an indication that the weighted sum of squared deviations
between the fitted function and the data points is the same as that expected for a random sample from a
population characterized by the function with the current value of the parameters and the given standard
deviations.
If the standard deviation for the population is not constant, as in counting statistics where variance = counts,
then each point should be individually weighted when comparing the observed sum of deviations and the
expected sum of deviations.
At the conclusion fit reports ’stdfit’, the standard deviation of the fit, which is the rms of the residuals, andthe variance of the residuals, also called ’reduced chisquare’ when the data points are weighted. The numberof degrees of freedom (the number of data points minus the number of fitted parameters) is used in theseestimates because the parameters used in calculating the residuals of the datapoints were obtained from thesame data. If the data points have weights, gnuplot calculates the so-called p-value, i.e. one minus the
cumulative distribution function of the chisquare-distribution for the number of degrees of freedom and theresulting chisquare, see fit practical guidelines (p. 109). These values are exported to the variables
FIT_NDF = Number of degrees of freedom
FIT_WSSR = Weighted sum-of-squares residual
FIT_STDFIT = sqrt(WSSR/NDF)
FIT_P = p-value

To estimate confidence levels for the parameters, one can use the minimum chisquare obtained from the fit
and chisquare statistics to determine the value of chisquare corresponding to the desired confidence level,
but considerably more calculation is required to determine the combinations of parameters which produce
such values.
Rather than determine confidence intervals, fit reports parameter error estimates which are readily obtained
from the variance-covariance matrix after the final iteration. By convention, these estimates are called"standard errors" or "asymptotic standard errors", since they are calculated in the same way as the standard
errors (standard deviation of each parameter) of a linear least-squares problem, even though the statisticalconditions for designating the quantity calculated to be a standard deviation are not generally valid for anonlinear least-squares problem. The asymptotic standard errors are generally over-optimistic and should
not be used for determining confidence levels, but are useful for qualitative purposes.
The final solution also produces a correlation matrix indicating correlation of parameters in the region of thesolution; The main diagonal elements, autocorrelation, are always 1; if all parameters were independent, theoff-diagonal elements would be nearly 0. Two variables which completely compensate each other would havean off-diagonal element of unit magnitude, with a sign depending on whether the relation is proportional or
inversely proportional. The smaller the magnitudes of the off-diagonal elements, the closer the estimates ofthe standard deviation of each parameter would be to the asymptotic standard error.
Practical guidelines
If you have a basis for assigning weights to each data point, doing so lets you make use of additional knowledge
about your measurements, e.g., take into account that some points may be more reliable than others. Thatmay affect the final values of the parameters.

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Weighting the data provides a basis for interpreting the additional fit output after the last iteration. Even
if you weight each point equally, estimating an average standard deviation rather than using a weight of 1
makes WSSR a dimensionless variable, as chisquare is by definition.
Each fit iteration will display information which can be used to evaluate the progress of the fit. (An ’*’
indicates that it did not find a smaller WSSR and is trying again.) The ’sum of squares of residuals’, also
called ’chisquare’, is the WSSR between the data and your fitted function; fit has minimized that. At thisstage, with weighted data, chisquare is expected to approach the number of degrees of freedom (data points
minus parameters). The WSSR can be used to calculate the reduced chisquare (WSSR/ndf) or stdfit, thestandard deviation of the fit, sqrt(WSSR/ndf). Both of these are reported for the final WSSR.
If the data are unweighted, stdfit is the rms value of the deviation of the data from the fitted function, inuser units.
If you supplied valid data errors, the number of data points is large enough, and the model is correct, thereduced chisquare should be about unity. (For details, look up the ’chi-squared distribution’ in your favorite
statistics reference.) If so, there are additional tests, beyond the scope of this overview, for determining how
well the model fits the data.
A reduced chisquare much larger than 1.0 may be due to incorrect data error estimates, data errors notnormally distributed, systematic measurement errors, ’outliers’, or an incorrect model function. A plot of
the residuals, e.g., plot ’datafile’ using 1:($2-f($1)), may help to show any systematic trends. Plotting
both the data points and the function may help to suggest another model.
Similarly, a reduced chisquare less than 1.0 indicates WSSR is less than that expected for a random sample
from the function with normally distributed errors. The data error estimates may be too large, the statisticalassumptions may not be justified, or the model function may be too general, fitting fluctuations in a particularsample in addition to the underlying trends. In the latter case, a simpler function may be more appropriate.
The p-value of the fit is one minus the cumulative distribution function of the chisquare-distribution for thenumber of degrees of freedom and the resulting chisquare. This can serve as a measure of the goodness-of-fit.
The range of the p-value is between zero and one. A very small or large p-value indicates that the model does
not describe the data and its errors well. As described above, this might indicate a problem with the data,
its errors or the model, or a combination thereof. A small p-value might indicate that the errors have been
underestimated and the errors of the final parameters should thus be scaled. See also set fit errorscaling(p. 167).
You’ll have to get used to both fit and the kind of problems you apply it to before you can relate thestandard errors to some more practical estimates of parameter uncertainties or evaluate the significance ofthe correlation matrix.
Note that fit, in common with most nonlinear least-squares implementations, minimizes the weighted sumof squared distances (y-f(x))**2. It does not provide any means to account for "errors" in the values ofx, only in y. Also, any "outliers" (data points outside the normal distribution of the model) will have an
exaggerated effect on the solution.

Control
There are two environment variables that can be defined to affect fit. The environment variables must be
defined before gnuplot is executed; how to do so depends on your operating system.
FIT_LOGchanges the name (and/or path) of the file to which the fit log will be written. The default is to write"fit.log" in the current working directory. This can be overwritten at run time using the command set fit
logfile.
FIT_SCRIPT

specifies a command that may be executed after an user interrupt. The default is replot, but a plot orload command may be useful to display a plot customized to highlight the progress of the fit. This can bechanged at run time using set fit script.

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For many other run time adjustments to way fit works, see set fit (p. 167).

Error recovery
Starting with gnuplot version 6, the fit command always returns to the next command input line regardlessof the success or failure of fitting. This allows scripted recovery from fit errors. The variable FIT ERROR is
set to 0 on success, non-zero on error. This example plots however many of five data sets can be successfully
fit. Failure for data set 2 would not prevent fitting data sets 3 through 5.
do for [i=1:5] {DATA = sprintf("Data_%05d.dat", i)fit f(x) DATA via a,b,c
if (FIT_ERROR || !FIT_CONVERGED) {print "Fit failed for ", DATA
continue}
set output sprintf("dataset_%05.png", i)plot DATA, f(x)unset output}

Multi-branch
In multi-branch fitting, multiple data sets can be simultaneously fit with functions of one independent
variable having common parameters by minimizing the total WSSR. The function and parameters (branch)for each data set are selected by using a ’pseudo-variable’, e.g., either the dataline number (a ’column’ index
of -1) or the datafile index (-2), as the second independent variable.
Example: Given two exponential decays of the form, z=f(x), each describing a different data set but having
a common decay time, estimate the values of the parameters. If the datafile has the format x:z:s, thenf(x,y) = (y==0) ? a*exp(-x/tau) : b*exp(-x/tau)
fit f(x,y) 'datafile' using 1:-2:2:3 via a, b, tau

For a more complicated example, see the file "hexa.fnc" used by the "fit.dem" demo.
Appropriate weighting may be required since unit weights may cause one branch to predominate if there isa difference in the scale of the dependent variable. Fitting each branch separately, using the multi-branchsolution as initial values, may give an indication as to the relative effect of each branch on the joint solution.

Starting values
Nonlinear fitting is not guaranteed to converge to the global optimum (the solution with the smallest sum ofsquared residuals, SSR), and can get stuck at a local minimum. The routine has no way to determine that;
it is up to you to judge whether this has happened.
fit may, and often will get "lost" if started far from a solution, where SSR is large and changing slowly as
the parameters are varied, or it may reach a numerically unstable region (e.g., too large a number causing
a floating point overflow) which results in an "undefined value" message or gnuplot halting.
To improve the chances of finding the global optimum, you should set the starting values at least roughly inthe vicinity of the solution, e.g., within an order of magnitude, if possible. The closer your starting values
are to the solution, the less chance of stopping at a false minimum. One way to find starting values is to plot
data and the fitting function on the same graph and change parameter values and replot until reasonablesimilarity is reached. The same plot is also useful to check whether the fit found a false minimum.
Of course finding a nice-looking fit does not prove there is no "better" fit (in either a statistical sense,characterized by an improved goodness-of-fit criterion, or a physical sense, with a solution more consistent
with the model.) Depending on the problem, it may be desirable to fit with various sets of starting values,
covering a reasonable range for each parameter.

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Time data
In fitting time data it is important to remember that gnuplot represents time as seconds since 1 January
1970. For example if you wanted to fit a quadratic model for the time dependence of something measured
over the course of one day in 2023, you might expect that it could be done using
T(x) = a + b*x + c*x*x
set xdata time
fit T(x) 'hits.dat' using 1:3 via a,b,cThis will probably fail, because internally the x values corresponding to that one day will have a range
something like [1.67746e+09 : 1.67754e+09]. The fractional change in x across the measured data will be
only about 1.e-05 and to guarantee convergence you would probably need many decimal places of accuracy
in the initial parameter estimates.
One solution is to recast the problem as change in time since the start of measurement.
set xdata time
# data format "27-02-2023 12:00:00 measurement"
timefmt = "%d-%m-%Y %H:%M:%S"
set timefmt timefmt
t0 = strptime( timefmt, "27-02-2023 00:00:00" )fit T(x) 'temperature.dat' using ($1-t0):3 via a,b,cThis shifts the range of the data to [0 : 86400], which is more tractable. Another possibility in this case isto ignore the date in column 1 and use relative time formats (tH/tM/tS) applied to column 2.
set timefmt "%tH:%tM:%tS"
fit T(x) 'temperature.dat' using 2:3 via a,b,c

Tips
Here are some tips to keep in mind to get the most out of fit. They’re not very organized, so you’ll have toread them several times until their essence has sunk in.
The two forms of the via argument to fit serve two largely distinct purposes. The via "file" form is bestused for (possibly unattended) batch operation, where you supply the starting parameter values in a file.
The via var1, var2, ... form is best used interactively, where the command history mechanism may be
used to edit the list of parameters to be fitted or to supply new startup values for the next try. This isparticularly useful for hard problems, where a direct fit to all parameters at once won’t work without goodstarting values. To find such, you can iterate several times, fitting only some of the parameters, until thevalues are close enough to the goal that the final fit to all parameters at once will work.
Make sure that there is no mutual dependency among parameters of the function you are fitting. For
example, don’t try to fit a*exp(x+b), because a*exp(x+b)=a*exp(b)*exp(x). Instead, fit either a*exp(x) orexp(x+b).
A technical issue: The larger the ratio of the largest and the smallest absolute parameter values, the slower
the fit will converge. If the ratio is close to or above the inverse of the machine floating point precision, it
may take next to forever to converge, or refuse to converge at all. You will either have to adapt your function
to avoid this, e.g., replace ’parameter’ by ’1e9*parameter’ in the function definition, and divide the starting
value by 1e9 or use set fit prescale which does this internally according to the parameter starting values.
If you can write your function as a linear combination of simple functions weighted by the parameters to be
fitted, by all means do so. That helps a lot, because the problem is no longer nonlinear and should converge
with only a small number of iterations, perhaps just one.
Some prescriptions for analysing data, given in practical experimentation courses, may have you first fit somefunctions to your data, perhaps in a multi-step process of accounting for several aspects of the underlying
theory one by one, and then extract the information you really wanted from the fitting parameters of thosefunctions. With fit, this may often be done in one step by writing the model function directly in terms ofthe desired parameters. Transforming data can also quite often be avoided, though sometimes at the cost ofgnuplot 6.0

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a more difficult fit problem. If you think this contradicts the previous paragraph about simplifying the fit
function, you are correct.
A "singular matrix" message indicates that this implementation of the Marquardt-Levenberg algorithm
can’t calculate parameter values for the next iteration. Try different starting values, writing the function inanother form, or a simpler function.
Finally, a nice quote from the manual of another fitting package (fudgit), that kind of summarizes all theseissues: "Nonlinear fitting is an art!"

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Function blocks
The function command signals the definition of a here-document containing a named block of gnuplot codethat can be called as a function. As with data blocks, the name of a function block must begin with a ’$’.
Up to nine named parameters may be specified as part of the definition. These names may be used inside
the function block as local variables. See local (p. 118) and scope (p. 64).
Once the function block is defined, you can invoke it by name anywhere that a normal function could be
used. If the return value is not relevant, the function block may be invoked by an "evaluate" command
rather than as part of an assignment expression.
Example:function $sinc(arg) << EOF
if (arg == 0) { return 1.0 }return sin(arg) / arg
EOF
gnuplot> plot $sinc(x) with lines title "sinc(x) as a function block"

It is not necessary to specify a list of named arguments to a function block at the time it is declared. The
number and values of arguments to the function passed from the command line can be be accessed frominside the function block as an integer variable ARGC and a corresponding array ARGV[ARGC]. See ARGV
(p. 103). This allows defining a function block that can operate on a variable number of arguments. Unlike
loading a file via a call statement, arguments are not repackaged as string variables (e.g. ARG1).
Example:function $max << EOF
local max = real("-Inf")
if (ARGC == 0) { return NaN }do for [i=1:ARGC] {if (max < ARGV[i]) {max = ARGV[i]}}return max
EOF
gnuplot> foo = $max( f(A), 2.0, C, Array[3] )gnuplot> baz = $max( foo, 100. )The primary motivation for function block support is to allow definition of complicated functions directlyin gnuplot. Execution is of course slower than if the same function were coded in C or Fortran, but this is
acceptable for many purposes. If execution speed matters then the function can be implemented later as aplugin instead (see plugins (p. 63)).
A second use for function blocks is to allow execution of gnuplot commands in a context they otherwise
could not appear. Suppose for example you want to plot data from two csv files, but one file uses commaseparated fields while the other uses semicolon-separated fields. Normally this property would have been set
by a previous set datafile command and would have to match all files used by the plot command. However
we can define a function block to invoke as a definition immediately before each file is referenced in the plot.
function $set_csv(char) << EOF
set datafile separator char
EOF
plot tmp=$set_csv(",") FILE1, tmp=$set_csv(";") FILE2

Limitations:• Data blocks and function blocks cannot be defined inside a function block.
• Pseudofile ’-’ cannot be used to read data inside a function block.
• These commands cannot be executed inside a function block: reset, shell, !<shell command>.
• A plot, replot, splot, refresh, stats, vfill, or fit command is accepted in a function block only ifnone of those commands is already in progress. E.g. you cannot use stats in a function block called
by a plot command, you cannot invoke plot from inside a fit command, etc.

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A non-trivial example of using function blocks to implement and plot a 15-term Lanczos approximation forthe complex lngamma function is provided in the demo collection as function block.dem
The function block implementation is slower by a factor of roughly 25 compared to the built-in lnGamma
function using the same algorithm coded directly in C. Nevertheless it is still fast enough for 3D interactive
rotation. The function definitions used in that demo are show below.
Function block implementation of logΓ(z) using a 15-term Lanczos approximationarray coef[15] = [ ... ]function $Lanczos(z) << EOD
local Sum = coef[1] + sum [k=2:15] coef[k] / (z + k - 1)
local temp = z + 671./128.
temp = (z + 0.5) * log(temp) - temp
temp = temp + log( sqrt(2*pi) * Sum/z )return temp
EOD
function $Reflect(z) << EOD
local w = $Lanczos(1.0 - z)
local temp = log( sin(pi * z) )return log(pi) - (w + temp)
EOD
my_lngamma(z) = (z == 0) ? NaN : (real(z) < 0.5) ? $Reflect(z) : $Lanczos(z)Use of function blocks is EXPERIMENTAL. Details may change before inclusion in a release version.

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Help
The help command displays built-in help. To specify information on a particular topic use the syntax:
help {<topic>}

If <topic> is not specified, a short message is printed about gnuplot. After help for the requested topic isgiven, a menu of subtopics is given; help for a subtopic may be requested by typing its name, extending thehelp request. After that subtopic has been printed, the request may be extended again or you may go backone level to the previous topic. Eventually, the gnuplot command line will return.
If a question mark (?) is given as the topic, the list of topics currently available is printed on the screen.

History
The history command prints or saves previous commands in the history list, or reexecutes a previous entry
in the list. To modify the behavior of this command or the location of the saved history file, see set history(p. 173).
Input lines with history as their first command are not stored in the command history.
Examples:history# show the complete history
history 5# show last 5 entries in the history
history quiet 5# show last 5 entries without entry numbers
history "hist.gp"# write the complete history to file hist.gp
history "hist.gp" append # append the complete history to file hist.gp
history 10 "hist.gp" # write last 10 commands to file hist.gp
history 10 "|head -5 >>diary.gp" # write 5 history commands using pipe
history ?load# show all history entries starting with "load"
history ?"set c"# like above, several words enclosed in quotes
hist !"set xr"# like above, several words enclosed in quotes
hist !55# reexecute the command at history entry 55

If
Syntax:if (<condition>) { <commands>;<commands><commands>} else if (<condition>) {<commands>} else {<commands>}

This version of gnuplot supports block-structured if/else statements. If the keyword if or else is immediately
followed by an opening "{", then conditional execution applies to all statements, possibly on multiple input
lines, until a matching "}" terminates the block. If commands may be nested.
Prior to gnuplot version 5 the scope of if/else commands was limited to a single input line. Now a multiline clause may be enclosed in curly brackets. The old syntax is still honored but cannot be used inside abracketed clause.
Old syntax:
if (<condition>) <command-line> [; else if (<condition>) ...; else ...]

If no opening "{" follows the if keyword, the command(s) in <command-line> will be executed if<condition> is true (non-zero) or skipped if <condition> is false (zero). Either case will consume commands on the input line until the end of the line or an occurrence of else. Note that use of ; to allow
multiple commands on the same line will not end the conditionalized commands.

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For
The plot, splot, set and unset commands may optionally contain an iteration clause. This has the effectof executing the basic command multiple times, each time re-evaluating any expressions that make use of
the iteration control variable. Iteration of arbitrary command sequences can be requested using the docommand. Two forms of iteration clause are currently supported:for [intvar = start:end{:increment}]
for [stringvar in "A B C D"]

Examples:plot for [filename in "A.dat B.dat C.dat"] filename using 1:2 with lines
plot for [basename in "A B C"] basename.".dat" using 1:2 with lines
set for [i = 1:10] style line i lc rgb "blue"
unset for [tag = 100:200] label tag

Nested iteration is supported:
set for [i=1:9] for [j=1:9] label i*10+j sprintf("%d",i*10+j) at i,j

See additional documentation for iteration (p. 56), do (p. 104).

Import
The import command associates a user-defined function name with a function exported by an external
shared object. This constitutes a plugin mechanism that extends the set of functions available in gnuplot.
Syntax:import func(x[,y,z,...]) from "sharedobj[:symbol]"

Examples:# make the function myfun, exported by "mylib.so" or "mylib.dll"# available for plotting or numerical calculation in gnuplot
import myfun(x) from "mylib"
import myfun(x) from "mylib:myfun"# same as above# make the function theirfun, defined in "theirlib.so" or "theirlib.dll"# available under a different nameimport myfun(x,y,z) from "theirlib:theirfun"

The program extends the name given for the shared object by either ".so" or ".dll" depending on theoperating system, and searches for it first as a full path name and then as a path relative to the current directory. The operating system itself may also search any directories in LD LIBRARY PATH or
DYLD LIBRARY PATH. See plugins (p. 63).

Load
The load command executes each line of the specified input file as if it had been typed in interactively. Files
created by the save command can later be loaded. Any text file containing valid gnuplot commands can be
executed by a load command. Files being loaded may themselves contain load or call commands. To passarguments to a loaded file, see call (p. 102).
Syntax:load "<input-file>"load $datablock

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The name of the input file must be enclosed in quotes.
The special filename "-" may be used to load commands from standard input. This allows a gnuplot
command file to accept some commands from standard input. Please see help for batch/interactive(p. 31) for more details.
On systems that support a popen function, the load file can be read from a pipe by starting the file namewith a ’<’.
Examples:load 'work.gnu'
load "func.dat"load "< loadfile_generator.sh"

The load command is performed implicitly on any file names given as arguments to gnuplot. These are
loaded in the order specified, and then gnuplot exits.
EXPERIMENTAL: It is also possible to execute commands from lines of text stored internally. See function
blocks (p. 114). A function block may be defined in-line or in an external file. Once the function block has
been defined the commands may be executed repeatedly using evaluate on the internal copy rather thanreloading the file.

Local
Syntax:local foo = <expression>
local array foo[size]

The local keyword introduces declaration of a variable whose scope is limited to the execution of the code
block in which it is declared. Declaration is optional, but without it all variables are global. If the name ofa local variable duplicates the name of a global variable, the global variable is shadowed until exit from thelocal scope. See scope (p. 64).
Local declarations may be used to prevent a global variable from being unintentionally overwritten by a callor load statement. They are particularly useful inside a function block. The local command is also valid
inside the code block in curly brackets following an if, else, do for, or while statement.
Example: Suppose you want to write a script "plot all data.gp" containing commands that plot a bunch ofdata sets. You want to call this convenience script from the command line or from other scripts withoutworrying that it trashes any variables with names "file" or "files" or "dataset" or "outfile". The variable"file" is inherently local because it is an iteration variable (see scope (p. 64)) but the other three names
need keyword local to protect them.
plot all data.gp:
local files = system("ls -1 *.dat")
do for [file in files] {local dataset = file[1:strstrt(file,".dat")-1]
local outfile = dataset . ".png"
set output outfile
plot file with lines title dataset}
unset output

Lower
See raise (p. 146).

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Pause
The pause command displays any text associated with the command and then waits a specified amount oftime or until the carriage return is pressed. pause is especially useful in conjunction with load files.
Syntax:pause <time> {"<string>"}
pause mouse {<endcondition>}{, <endcondition>} {"<string>"}
pause mouse close<time> may be any constant or floating-point expression. pause -1 will wait until a carriage return is hit,zero (0) won’t pause at all, and a positive number will wait the specified number of seconds.
If the current terminal supports mousing, then pause mouse will terminate on either a mouse click or on
ctrl-C. For all other terminals, or if mousing is not active, pause mouse is equivalent to pause -1.
If one or more end conditions are given after pause mouse, then any one of the conditions will terminate
the pause. The possible end conditions are keypress, button1, button2, button3, close, and any. If
the pause terminates on a keypress, then the ascii value of the key pressed is returned in MOUSE KEY.
The character itself is returned as a one character string in MOUSE CHAR. Hotkeys (bind command) aredisabled if keypress is one of the end conditions. Zooming is disabled if button3 is one of the end conditions.
In all cases the coordinates of the mouse are returned in variables MOUSE X, MOUSE Y, MOUSE X2,
MOUSE Y2. See mouse variables (p. 62).
Note: Since pause communicates with the operating system rather than the graphics, it may behave differently with different device drivers (depending upon how text and graphics are mixed).
Examples:pause -1
# Wait until a carriage return is hit
pause 3
# Wait three seconds
pause -1 "Hit return to continue"pause 10 "Isn't this pretty? It's a cubic spline."
pause mouse "Click any mouse button on selected data point"pause mouse keypress "Type a letter from A-F in the active window"
pause mouse button1,keypress
pause mouse any "Any key or button will terminate"

The variant "pause mouse key" will resume after any keypress in the active plot window. If you want towait for a particular key to be pressed, you can use a loop such as:
print "I will resume after you hit the Tab key in the plot window"
plot <something>pause mouse key
while (MOUSE_KEY != 9) {pause mouse key}

Pause mouse close
The command pause mouse close is a specific example of pausing to wait for an external event. In this casethe program waits for a "close" event from the plot window. Exactly how to generate such an event varies
with your desktop environment and configuration, but usually you can close the plot window by clicking
on some widget on the window border or by typing a hot-key sequence such as <alt><F4> or <ctrl>q. If
you are unsure whether a suitable widget or hot-key is available to the user, you may also want to define a
hot-key sequence using gnuplot’s own mechanism. See bind (p. 61).
The command sequence below may be useful when running gnuplot from a script rather than from thecommand line.
plot <...whatever...>bind all "alt-End" "exit gnuplot"
pause mouse close

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Pseudo-mousing during pause
Some terminals use the same window for text entry and graphical display, including terminal types dumb,sixel, kitty, and domterm. These terminals do not currently support mousing per se, but during apause mouse command they interpret keystrokes in the same way that a mousing terminal would. E.g.
left/right/up/down arrow keys change the view angle of 3D plots and perform incremental pan/zoom for2D plots, l toggles log-scale axes, a autoscales the current plot, h displays a list of key bindings. A carriage
return terminates the pause and restores normal command line processing.

Plot
plot and splot are the primary commands for drawing plots with gnuplot. They offer many different
graphical representations for functions and data. plot is used to draw 2D functions and data. splot draws
2D projections of 3D surfaces and data.
Syntax:plot {<ranges>} <plot-element> {, <plot-element>, <plot-element>}

Each plot element consists of a definition, a function, or a data source together with optional properties ormodifiers:
plot-element:{<iteration>}<definition> | {sampling-range} <function> | <data source>| keyentry{axes <axes>} {<title-spec>}{with <style>}

The graphical representation of each plot element is determined by the keyword with, e.g. with lines orwith boxplot. See plotting styles (p. 71).
The data to be plotted is either generated by a function (two functions if in parametric mode), read from adata file, read from a named data block that was defined previously, or extracted from an array. Multiple
datafiles, data blocks, arrays, and/or functions may be plotted in a single plot command separated bycommas. See data (p. 124), inline data (p. 55), functions (p. 138).
A plot-element that contains the definition of a function or variable does not create any visible output, see
third example below.
Examples:plot sin(x)plot sin(x), cos(x)plot f(x) = sin(x*a), a = .2, f(x), a = .4, f(x)plot "datafile.1" with lines, "datafile.2" with points
plot [t=1:10] [-pi:pi*2] tan(t), \"data.1" using (tan($2)):($3/$4) smooth csplines \axes x1y2 notitle with lines 5
plot for [datafile in "spinach.dat broccoli.dat"] datafile

See also show plot (p. 245).

Axes
There are four possible sets of axes available; the keyword <axes> is used to select the axes for which aparticular line should be scaled. x1y1 refers to the axes on the bottom and left; x2y2 to those on the top
and right; x1y2 to those on the bottom and right; and x2y1 to those on the top and left. Ranges specified
on the plot command apply only to the first set of axes (bottom left).

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BinaryBINARY DATA FILES:
It is necessary to provide the keyword binary after the filename. Adequate details of the file format mustbe given on the command line or extracted from the file itself for a supported binary filetype. In particular,
there are two structures for binary files, binary matrix format and binary general format.
The binary matrix format contains a two dimensional array of 32 bit IEEE float values plus an additional
column and row of coordinate values. In the using specifier of a plot command, column 1 refers to thematrix row coordinate, column 2 refers to the matrix column coordinate, and column 3 refers to the value
stored in the array at those coordinates.
The binary general format contains an arbitrary number of columns for which information must be specified
at the command line. For example, array, record, format and using can indicate the size, format anddimension of data. There are a variety of useful commands for skipping file headers and changing endianess.
There are a set of commands for positioning and translating data since often coordinates are not part of thefile when uniform sampling is inherent in the data. Unlike reading from a text or matrix binary file, generalbinary does not treat the generated columns as 1, 2 or 3 in the using list. Instead column 1 refers to column
1 of the file, or as specified in the format list.
There are global default settings for the various binary options which may be set using the same syntax as theoptions when used as part of the (s)plot <filename> binary ... command. This syntax is set datafile
binary .... The general rule is that common command-line specified parameters override file-extracted
parameters which override default parameters.
Binary matrix is the default binary format when no keywords specific to binary general are given, i.e.,array, record, format, filetype.
General binary data can be entered at the command line via the special file name ’-’. However, this isintended for use through a pipe where programs can exchange binary data, not for keyboards. There isno "end of record" character for binary data. Gnuplot continues reading from a pipe until it has read thenumber of points declared in the array qualifier. See binary matrix (p. 246) or binary general (p. 121)
for more details.
The index keyword is not supported, since the file format allows only one surface per file. The every andusing specifiers are supported. using operates as if the data were read in the above triplet form. Binary
File Splot Demo.
GeneralThe binary keyword appearing alone indicates a binary data file that contains both coordinate information
describing a non-uniform grid and the value of each grid point (see binary matrix (p. 246)). Binary data
in any other format requires additional keywords to describe the layout of the data. Unfortunately the syntaxof these required additional keywords is convoluted. Nevertheless the general binary mode is particularly
useful for application programs sending large amounts of data to gnuplot.
Syntax:plot '<file_name>' {binary <binary list>} ...
splot '<file_name>' {binary <binary list>} ...

General binary format is activated by keywords in <binary list> pertaining to information about file structure, i.e., array, record, format or filetype. Otherwise, non-uniform matrix binary format is assumed.
(See binary matrix (p. 246) for more details.)
Gnuplot knows how to read a few standard binary file types that are fully self-describing, e.g. PNG images.
Type show datafile binary at the command line for a list. Apart from these, you can think of binary data
files as conceptually the same as text data. Each point has columns of information which are selected via theusing specification. If no format string is specified, gnuplot will read in a number of binary values equal
to the largest column given in the <using list>. For example, using 1:3 will result in three columns being

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read, of which the second will be ignored. Certain plot types have an associated default using specification.
For example, with image has a default of using 1, while with rgbimage has a default of using 1:2:3.
Array
Describes the sampling array dimensions associated with the binary file. The coordinates will be generated
by gnuplot. A number must be specified for each dimension of the array. For example, array=(10,20)
means the underlying sampling structure is two-dimensional with 10 points along the first (x) dimension and
20 points along the second (y) dimension. A negative number indicates that data should be read until theend of file. If there is only one dimension, the parentheses may be omitted. A colon can be used to separate
the dimensions for multiple records. For example, array=25:35 indicates there are two one-dimensional
records in the file.
RecordThis keyword serves the same function as array and has the same syntax. However, record causes gnuplot
to not generate coordinate information. This is for the case where such information may be included in oneof the columns of the binary data file.
Skip
This keyword allows you to skip sections of a binary file. For instance, if the file contains a 1024 byte header
before the start of the data region you would probably want to use
plot '<file_name>' binary skip=1024 ...

If there are multiple records in the file, you may specify a leading offset for each. For example, to skip 512
bytes before the 1st record and 256 bytes before the second and third records
plot '<file_name> binary record=356:356:356 skip=512:256:256 ...

Format
The default binary format is a float. For more flexibility, the format can include details about variable sizes.
For example, format="%uchar%int%float" associates an unsigned character with the first using column,
an int with the second column and a float with the third column. If the number of size specifications is lessthan the greatest column number, the size is implicitly taken to be similar to the last given variable size.
Furthermore, similar to the using specification, the format can include discarded columns via the * characterand have implicit repetition via a numerical repeat-field. For example, format="%*2int%3float" causes
gnuplot to discard two ints before reading three floats. To list variable sizes, type show datafile binary
datasizes. There are a group of names that are machine dependent along with their sizes in bytes for theparticular compilation. There is also a group of names which attempt to be machine independent.
EndianOften the endianess of binary data in the file does not agree with the endianess used by the platform on which
gnuplot is running. Several words can direct gnuplot how to arrange bytes. For example endian=little
means treat the binary file as having byte significance from least to greatest. The options arelittle:big:
default:
swap (swab):

least significant to greatest significancegreatest significance to least significanceassume file endianess is the same as compiler
Interchange the significance. (If things
don't look right, try this.)

Gnuplot can support "middle" ("pdp") endian if it is compiled with that option.

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Filetype
For some standard binary file formats gnuplot can extract all the necessary information from the file inquestion. As an example, "format=edf" will read ESRF Header File format files. For a list of the currently
supported file formats, type show datafile binary filetypes.
There is a special file type called auto for which gnuplot will check if the binary file’s extension is a quasistandard extension for a supported format.
Command line keywords may be used to override settings extracted from the file. The settings from the file
override any defaults. See set datafile binary (p. 163).
Avs avs is one of the automatically recognized binary file types for images. AVS is an extremely simple
format, suitable mostly for streaming between applications. It consists of 2 longs (xwidth, ywidth) followed
by a stream of pixels, each with four bytes of information alpha/red/green/blue.
Edf edf is one of the automatically recognized binary file types for images. EDF stands for ESRF Data
Format, and it supports both edf and ehf formats (the latter means ESRF Header Format). More information
on specifications can be found at
http://www.edfplus.info/specs

Png If gnuplot was configured to use the libgd library for png/gif/jpeg output, then it can also be used toread these same image types as binary files. You can use an explicit commandplot 'file.png' binary filetype=png

Or the file type will be recognized automatically from the extension if you have previously requested
set datafile binary filetype=auto

Keywords
The following keywords apply only when generating coordinates from binary data files. That is, the control
mapping the individual elements of a binary array, matrix, or image to specific x/y/z positions.
Scan A great deal of confusion can arise concerning the relationship between how gnuplot scans a binary fileand the dimensions seen on the plot. To lessen the confusion, conceptually think of gnuplot always scanningthe binary file point/line/plane or fast/medium/slow. Then this keyword is used to tell gnuplot how to map
this scanning convention to the Cartesian convention shown in plots, i.e., x/y/z. The qualifier for scan is a
two or three letter code representing where point is assigned (first letter), line is assigned (second letter), andplane is assigned (third letter). For example, scan=yx means the fastest, point-by-point, increment should
be mapped along the Cartesian y dimension and the middle, line-by-line, increment should be mapped along
the x dimension.
When the plotting mode is plot, the qualifier code can include the two letters x and y. For splot, it can
include the three letters x, y and z.
There is nothing restricting the inherent mapping from point/line/plane to apply only to Cartesian coordinates. For this reason there are cylindrical coordinate synonyms for the qualifier codes where t (theta), r
and z are analogous to the x, y and z of Cartesian coordinates.
Transpose Shorthand notation for scan=yx or scan=yxz. I.e. it affects the assignment of pixels to scanlines during input. To instead transpose an image when it is displayed try
plot 'imagefile' binary filetype=auto flipx rotate=90deg with rgbimage

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Dx, dy, dz When gnuplot generates coordinates, it uses the spacing described by these keywords. For
example dx=10 dy=20 would mean space samples along the x dimension by 10 and space samples along
the y dimension by 20. dy cannot appear if dx does not appear. Similarly, dz cannot appear if dy does
not appear. If the underlying dimensions are greater than the keywords specified, the spacing of the highest
dimension given is extended to the other dimensions. For example, if an image is being read from a file andonly dx=3.5 is given gnuplot uses a delta x and delta y of 3.5.
The following keywords also apply only when generating coordinates. However they may also be used withmatrix binary files.
Flipx, flipy, flipz Sometimes the scanning directions in a binary datafile are not consistent with thatassumed by gnuplot. These keywords can flip the scanning direction along dimensions x, y, z.
Origin When gnuplot generates coordinates based upon transposition and flip, it attempts to always
position the lower left point in the array at the origin, i.e., the data lies in the first quadrant of a Cartesiansystem after transpose and flip.
To position the array somewhere else on the graph, the origin keyword directs gnuplot to position the lower
left point of the array at a point specified by a tuple. The tuple should be a double for plot and a triple for
splot. For example, origin=(100,100):(100,200) is for two records in the file and intended for plotting
in two dimensions. A second example, origin=(0,0,3.5), is for plotting in three dimensions.
Center Similar to origin, this keyword will position the array such that its center lies at the point givenby the tuple. For example, center=(0,0). Center does not apply when the size of the array is Inf.
Rotate The transpose and flip commands provide some flexibility in generating and orienting coordinates.
However, for full degrees of freedom, it is possible to apply a rotational vector described by a rotational
angle in two dimensions.
The rotate keyword applies to the two-dimensional plane, whether it be plot or splot. The rotation is donewith respect to the positive angle of the Cartesian plane.
The angle can be expressed in radians, radians as a multiple of pi, or degrees. For example, rotate=1.5708,
rotate=0.5pi and rotate=90deg are equivalent.
If origin is specified, the rotation is done about the lower left sample point before translation. Otherwise,
the rotation is done about the array center.
Perpendicular For splot, the concept of a rotational vector is implemented by a triple representing thevector to be oriented normal to the two-dimensional x-y plane. Naturally, the default is (0,0,1). Thus
specifying both rotate and perpendicular together can orient data myriad ways in three-space.
The two-dimensional rotation is done first, followed by the three-dimensional rotation. That is, if R’ is therotational 2 x 2 matrix described by an angle, and P is the 3 x 3 matrix projecting (0,0,1) to (xp,yp,zp),
let R be constructed from R’ at the upper left sub-matrix, 1 at element 3,3 and zeros elsewhere. Then thematrix formula for translating data is v’ = P R v, where v is the 3 x 1 vector of data extracted from thedata file. In cases where the data of the file is inherently not three-dimensional, logical rules are used toplace the data in three-space. (E.g., usually setting the z-dimension value to zero and placing 2D data inthe x-y plane.)

Data
Data provided in a file can be plotted by giving the name of the file (enclosed in single or double quotes) on
the plot command line. Data may also come from an input stream that is not a file. See special-filenames(p. 134), piped-data (p. 135), datablocks (p. 55).

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Syntax:plot '<file_name>' {binary <binary list>}{{nonuniform|sparse} matrix}{index <index list> | index "<name>"}{every <every list>}{skip <number-of-lines>}{using <using list>}{convexhull} {concavehull}{smooth <option>}{bins <options>}{mask}{volatile} {zsort} {noautoscale}

The modifiers binary, index, every, skip, using, smooth, bins, mask, convexhull, concavehull, andzsort are discussed separately. In brief• skip N tells the program to ignore N lines at the start of the input file• binary indicates that the file contains binary data rather than text
• index selects which data sets in a multi-data-set file are to be plotted• every specifies which points within a single data set are to be plotted• using specifies which columns in the file are to be used in which order• smooth performs simple filtering, interpolation, or curve-fitting of the data prior to plotting• convexhull either alone or in combination with smooth replaces the points in the input data set witha new set of points that constitute the vertices of a bounding polygon.
• bins sorts individual input points into equal-sized intervals along x and plots a single accumulated
value per interval• mask filters the data through a previously defined mask to plot only a selected subset of pixels in animage or a selected region of a pm3d surface.
• volatile indicates that the content of the file may not be available to reread later and therefore it
should be retained internally for re-use.
splot has a similar syntax but does not support bins and supports only a few smooth options.
The noautoscale keyword means that the points making up this plot will be ignored when automaticallydetermining axis range limits.
TEXT DATA FILES:
Each non-empty line in a data file describes one data point, except that records beginning with # will betreated as comments and ignored.
Depending on the plot style and options selected, from one to eight values are read from each line andassociated with a single data point. See using (p. 135).
The individual records on a single line of data must be separated by white space (one or more blanks ortabs) or a special field separator character which is specified by the set datafile command. A single field
may itself contain white space characters if the entire field is enclosed in a pair of double quotes, or if a field
separator other than white space is in effect. Whitespace inside a pair of double quotes is ignored whencounting columns, so the following datafile line has three columns:
1.0 "second column" 3.0

Data may be written in exponential format with the exponent preceded by the letter e or E. The fortranexponential specifiers d, D, q, and Q may also be used if the command set datafile fortran is in effect.
Blank records in a data file are significant. Single blank records designate discontinuities in a plot; no line
will join points separated by a blank records (if they are plotted with a line style). Two blank records in arow indicate a break between separate data sets. See index (p. 130).

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If autoscaling has been enabled (set autoscale), the axes are automatically extended to include all datapoints, with a whole number of tic marks if tics are being drawn. This has two consequences: i) For splot,
the corner of the surface may not coincide with the corner of the base. In this case, no vertical line is drawn.
ii) When plotting data with the same x range on a dual-axis graph, the x coordinates may not coincide if
the x2tics are not being drawn. This is because the x axis has been autoextended to a whole number of tics,
but the x2 axis has not. The following example illustrates the problem:
reset; plot '-', '-' axes x2y1
1 1
19 19
e
1 1
19 19
e

To avoid this, you can use the noextend modifier of the set autoscale or set [axis]range commands.
This turns off extension of the axis range to include the next tic mark.
Label coordinates and text can also be read from a data file (see labels (p. 87)).
Columnheaders
Extra lines at the start of a data file may be explicitly ignored using the skip keyword in the plot command.
A single additional line containing text column headers may be present. It is skipped automatically if the plot
command refers explicitly to column headers, e.g. by using them for titles. Otherwise you may need to skip
it explicitly either by adding one to the skip count or by setting the attribute set datafile columnheaders.
See skip (p. 131), columnhead (p. 47), autotitle columnheader (p. 177), set datafile (p. 161).
Csv files
Syntax:set datafile separator {whitespace | tab | comma | "chars"}"csv" is short for "comma-separated values". The term "csv file" is loosely applied to files in which data
fields are delimited by a specific character, not necessarily a comma. To read data from a csv file you musttell gnuplot what the field-delimiting character is. For instance to read from a file using semicolon as a field
delimiter:
set datafile separator ";"See set datafile separator (p. 162). This applies only to files used for input. To create a csv file on
output, use the corresponding separator option to set table.
Every
The every keyword allows a periodic sampling of a data set to be plotted.
For ordinary files a "point" single record (line); a "block" of data is a set of consecutive records with blanklines before and after the block.
For matrix data a "block" and "point" correspond to "row" and "column". See matrix every (p. 248).
Syntax:plot 'file' every {<point_incr>}{:{<block_incr>}{:{<start_point>}{:{<start_block>}{:{<end_point>}{:<end_block>}}}}}

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127

The data points to be plotted are selected according to a loop from <start point> to <end point> withincrement <point incr> and the blocks according to a loop from <start block> to <end block> withincrement <block incr>.
The first datum in each block is numbered ’0’, as is the first block in the file.
Note that records containing unplottable information are counted.
Any of the numbers can be omitted; the increments default to unity, the start values to the first point or
block, and the end values to the last point or block. ’:’ at the end of the every option is not permitted. If
every is not specified, all points in all lines are plotted.
Examples:every :::3::3
every :::::9
every 2:2
every ::5::15# selects just the fourth block ('0' is first)# selects the first 10 blocks# selects every other point in every other block# selects points 5 through 15 in each block

See simple plot demos (simple.dem), Non-parametric splot demos, and Parametric splot demos.
Example datafile
This example plots the data in the file "population.dat" and a theoretical curve:
pop(x) = 103*exp((1965-x)/10)
set xrange [1960:1990]
plot 'population.dat', pop(x)The file "population.dat" might contain:# Gnu population in Antarctica since 1965
1965
103
1970
55
1975
34
1980
24
1985
10

Binary examples:# Selects two float values (second one implicit) with a float value# discarded between them for an indefinite length of 1D data.
plot '<file_name>' binary format="%float%*float" using 1:2 with lines# The data file header contains all details necessary for creating# coordinates from an EDF file.
plot '<file_name>' binary filetype=edf with image
plot '<file_name>.edf' binary filetype=auto with image# Selects three unsigned characters for components of a raw RGB image# and flips the y-dimension so that typical image orientation (start# at top left corner) translates to the Cartesian plane. Pixel# spacing is given and there are two images in the file. One of them# is translated via origin.
plot '<file_name>' binary array=(512,1024):(1024,512) format='%uchar' \dx=2:1 dy=1:2 origin=(0,0):(1024,1024) flipy u 1:2:3 w rgbimage# Four separate records in which the coordinates are part of the# data file. The file was created with a endianess different from# the system on which gnuplot is running.
splot '<file_name>' binary record=30:30:29:26 endian=swap u 1:2:3# Same input file, but this time we skip the 1st and 3rd records
splot '<file_name>' binary record=30:26 skip=360:348 endian=swap u 1:2:3

See also binary matrix (p. 246).

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Filters
Filter operations are applied immediately after reading input data, before applying any smoothing or stylespecific processing options. In general the purpose of a filter is to replace the original full set of input points
with a selected subset of points, possibly modified, regrouped, or reordered, The filters currently supported
are bins, convexhull, concavehull, mask, sharpen, and zsort.
Bins Syntax:
plot 'DATA' using <XCOL> {:<YCOL>} bins{=<NBINS>}{binrange [<LOW>:<HIGH>]} {binwidth=<width>}{binvalue={sum|avg}}

The bins option to a plot command first assigns the original data to equal width bins on x and then plots
a single value per bin. The default number of bins is controlled by set samples, but this can be changed
by giving an explicit number of bins in the command.
If no binrange is given, the range is taken from the extremes of the x values found in ’DATA’.
Given the range and the number of bins, bin width is calculated automatically and points are assigned tobins 0 to NBINS-1
BINWIDTH = (HIGH - LOW) / (NBINS-1)
xmin = LOW - BINWIDTH/2
xmax = HIGH + BINWIDTH/2
first bin holds points with (xmin <= x < xmin + BINWIDTH)
last bin holds points with (xmax-BINWIDTH <= x < xman)
each point is assigned to bin i = floor(NBINS * (x-xmin)/(xmax-xmin))

Alternatively you can provide a fixed bin width, in which case nbins is calculated as the smallest number ofbins that will span the range.
On output bins are plotted or tabulated by midpoint. E.g. if the program calculates bin width as shown
above, the x coordinate output for the first bin is x=LOW (not x=xmin).
If only a single column is given in the using clause then each data point contributes a count of 1 to theaccumulation of total counts in the bin for that x coordinate value. If a second column is given then thevalue in that column is added to the accumulation for the bin. Thus the following two plot commands areequivalent:plot 'DATA" using N bins=20
set samples 20
plot 'DATA' using (column(N)):(1)

By default the y value plotted for each bin is the sum of the y values over all points in that bin. This
corresponds to option binvalue=sum. The alternative binvalue=avg plots the mean y value for points
in that bin.
For related processing options see smooth frequency (p. 133) and smooth kdensity (p. 134).
Convexhull Convexhull is not a plot style. It can appear either alone as a filter keyword or in combination
with smooth path and/or expand <increment>.
plot FOO using x:y convexhull
plot FOO using x:y convexhull smooth pathplot FOO using x:y convexhull expand <increment> {smooth path}gnuplot 6.0
The points in FOO are replaced by a subset of the original points that constitute the unique bounding convex
polygon, the convex hull. The vertices of this polygon
are output in clockwise order to form a closed curve. The
first and last points of the generated curve are equal,
making it suitable for plotting with styles lines, polygons, or filledcurves. The convex hull may also be
useful as a mask to selectively render the region of animage or a pm3d surface that contains all the original
data points. See masking (p. 89).

129

Convex hull bounding scattered points
20
10
0
-10
-20
-20

-10

0

10

20

If the keyword smooth is present, the vertices are then used as guide points to generate a smooth closed
curve (see smooth path (p. 132)). By default this smoothed curve runs through the bounding points.
The optional expand keyword and increment shift the edge segments of the hull away from the interior
by an incremental distance. The displaced segments are then connected using miter joins; this means thateach vertex of the original hull is replaced by two vertices, since there is now a gap between the to adjoiningedges.

Concavehull

Present only if your copy of gnuplot was configured –enable-chi-shapes.

Concavehull is not a plot style. It is a filter that finds a bounding polygon, a "hull", of the input data
points and replaces the original points with an ordered subset of points that lie along the perimeter of thispolygon. Unlike the convex hull, which is uniquely defined for any set of points, more than one concave hullis possible. Various schemes for selecting a concave hull exist; gnuplot generates hulls that are χ-shapes as
defined by Duckham et al. (2008) Patttern Recognition 41:3224-3236.
For a given set of points, a χ-shape is generated by iterconcave hull
chi_length = +Inf (convex hull)
chi_length = 25.0
ative removal of triangles from the Delaunay triangulation. Each iteration removes a single triangle subject tothe criteria: (1) A triangle is only eligible for removal if
this would not reduce the connectivity of the boundedshape to contact at a single point; (2) one edge of the
chi_length = 20.0
chi_length = 16.0
triangle is the longest segment of the current perimeter; (3) this edge is longer than a pre-selected characteristic length parameter that fully determines the χshape. In gnuplot this characteristic length parameteris taken from user variable chi length. Iteration stops
when there are no remaining eligible triangles. If chi length is large, no triangles are removed and theχ-shape is the original perimeter, i.e. the convex hull. As chi length is reduced, more and more triangles
are removed and the resulting shape becomes increasingly less convex. Too-small values of chi length are
undesirable.
Appropriate choice of chi length depends strongly on
the density and distribution of the input data points.
If no value for chi length has been set by the user,
gnuplot will choose one automatically but there is no
guarantee that this value is suitable for your data. For
the data used in the figures shown here gnuplot would
choose chi length=22.6 by default, which is 0.6 of thelength of the longest edge in the convex hull. You canchange the fraction of the longest edge used as a default
with the command set chi shape fraction <value>

concave hull smooth path expand 3.0
chi_length = +Inf (convex hull)
chi_length = 25.0

chi_length = 20.0

chi_length = 16.0

The value of chi length used in the current plot, whether provided by the user or chosen by the program,is saved to variable GPVAL CHI LENGTH.

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The optional expand keyword and increment shift each edge segment of the hull away from the interior by
a fixed distance. This creates a new set of points describing a closed curve that lies outside all of the original
points. It can be combined with smooth path.
Mask
plot FOO using 1:2:3 mask with {pm3d|image}Once a mask has been defined, you can use it as a filter to select a subset of points from an image or pm3d
plot. See masking (p. 89).
Sharpen The sharpen filter applies only to function plots. It looks for extrema in the function being
plotted, which may not lie exactly at any of the x values sampled to generate the component line segments
making up the graph. The true local extrema are found by bisection and added to the set of sampled points.
This reduces but does not entirely eliminate truncation of sharp peaks due to coarse sampling.
Example:set samples 150
set xrange [-8:8]
plot abs(sqrt(sin(x))) sharpen

Without the "sharpen" keyword, the resulting graph shows a continuous curve with minima at intervals ofpi that should reach zero but are artefactually truncated to apparent minimal y values between 0.02 and0.20. Adding the "sharpen" keyword produces instead a correct representation of the function with periodic
sharp minima that reach y=0.
Zsort
plot FOO using x:y:z:color zsort with points lc palette

Input data is sorted immediately after input, prior to applying any smoothing options. Note that somesmoothing options will re-sort the data, in which case zsort has no effect on the plot. If z is not auto-scaled,
points with z value out of range are flagged but not deleted.
The intended use is to filter presentation of 2D scatter plots with a huge number of points so that the
distribution of high-scoring points remains evident. Sorting the points on z guarantees that points with ahigh z-value will not be obscured by points with lower z-values.
Index
The index keyword allows you to select specific data sets in a multi-data-set file for plotting. For arrayindexing please see arrays (p. 52).
Syntax:plot 'file' index { <m>{:<n>{:<p>}} | "<name>" }Data sets are separated by pairs of blank records. index <m> selects only set <m>; index <m>:<n>selects sets in the range <m> to <n>; and index <m>:<n>:<p> selects indices <m>, <m>+<p>,<m>+2<p>, etc., but stopping at <n>. Following C indexing, the index 0 is assigned to the first data set
in the file. Specifying too large an index results in an error message. If <p> is specified but <n> is left
blank then every <p>-th dataset is read until the end of the file. If index is not specified, the entire file isplotted as a single data set.
Example:plot 'file' index 4:5

For each point in the file, the index value of the data set it appears in is available via the pseudo-column
column(-2). This leads to an alternative way of distinguishing individual data sets within a file as shown
below. This is more awkward than the index command if all you are doing is selecting one data set for
plotting, but is very useful if you want to assign different properties to each data set. See pseudocolumns(p. 137), lc variable (p. 58).
Example:gnuplot 6.0

131plot 'file' using 1:(column(-2)==4 ? $2 : NaN)
# very awkward
plot 'file' using 1:2:(column(-2)) linecolor variable # very useful!

index ’<name>’ selects the data set with name ’<name>’. Names are assigned to data sets in comment
lines. The comment character and leading white space are removed from the comment line. If the resulting
line starts with <name>, the following data set is now named <name> and can be selected.
Example:plot 'file' index 'Population'

Please note that every comment that starts with <name> will name the following data set. To avoid
problems it may be useful to choose a naming scheme like ’== Population ==’ or ’[Population]’.

Skip
The skip keyword tells the program to skip lines at the start of a text (i.e. not binary) data file. The linesthat are skipped do not count toward the line count used in processing the every keyword. Note that skip
N skips lines only at the start of the file, whereas every ::N skips lines at the start of every block of datain the file. See also binary skip (p. 122) for a similar option that applies to binary data files.
Smoothgnuplot includes a few routines for interpolation and other operations applied to data as it is input; these aregrouped under the smooth option. More sophisticated data processing may be performed by preprocessing
the data externally or by using fit with an appropriate model. See also the discussion of plot filters(p. 128).
Syntax:smooth {unique | frequency | fnormal | cumulative | cnormal| csplines | acsplines | mcsplines bezier | sbezier| path| kdensity {bandwidth} {period}| unwrap}

The unique, frequency, fnormal, cumulative and cnormal options sort the data on x and then plot
some aspect of the distribution of x values.
The spline and Bezier options determine coefficients describing a continuous curve between the endpointsof the data. This curve is then plotted in the same manner as a function, that is, by finding its value at
uniform intervals along the abscissa (see set samples (p. 213)) and connecting these points with straightline segments. If the data set is interrupted by blank lines or undefined values a separate continuous curveis fit for each uninterrupted subset of the data. Adjacent separately fit segments may be separated by a gap
or discontinuity.
unwrap manipulates the data to avoid jumps of more than pi by adding or subtracting multiples of 2*pi.
If autoscale is in effect, axis ranges will be computed for the final curve rather than for the original data.
If autoscale is not in effect, and a spline curve is being generated, sampling of the spline fit is done acrossthe intersection of the x range covered by the input data and the fixed abscissa range defined by set xrange.
If too few points are available to apply the requested smoothing operation an error message is produced.
The smooth options have no effect on function plots. Only smooth path is possible in polar coordinate
mode.
Smoothing in 3D plots (splot) is currently limited to generating a natural cubic spline to pass through a
set of 3D points. In the general case the splines are generated along a trajectory (smooth path). For a
2D projection of 3D data smooth csplines acts as it does in 2D. Either keyword is accepted in an splot
command.
splot $DATA using 1:2:3 smooth path with lines

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Acsplines The smooth acsplines option approximates the data with a natural smoothing spline. Afterthe data are made monotonic in x (see smooth unique (p. 133)), a curve is piecewise constructed fromsegments of cubic polynomials whose coefficients are found by fitting to the individual data points weighted
by the value, if any, given in the third column of the using spec. The default is equivalent toplot 'data-file' using 1:2:(1.0) smooth acsplines

Qualitatively, the absolute magnitude of the weights determines the number of segments used to construct
the curve. If the weights are large, the effect of each datum is large and the curve approaches that producedby connecting consecutive points with natural cubic splines. If the weights are small, the curve is composedof fewer segments and thus is smoother; the limiting case is the single segment produced by a weighted linear
least squares fit to all the data. The smoothing weight can be expressed in terms of errors as a statisticalweight for a point divided by a "smoothing factor" for the curve so that (standard) errors in the file can beused as smoothing weights.
Example:sw(x,S)=1/(x*x*S)
plot 'data_file' using 1:2:(sw($3,100)) smooth acsplines
splot 'data_file' using 1:2:3:(sw($4,100)) smooth acsplines

splot ... smooth acsplines with lines fits splines to the x, y, and z coordinates of successive data points.
Unlike the 2D case, the points are not sorted first so it is possible to fit splines to a trajectory containing
loops. Caution: In the general 3D case there are many more spline terms fitted, so the weight value mustbe larger to achieve a comparable effect. Also note that fractional path length is used as the implicit control
variable and therefore the intervals being weighted do not match the projections onto a single axis.
Bezier The smooth bezier option approximates the data with a Bezier curve of degree n (the number ofdata points) that connects the endpoints.
Bins

smooth bins is the same as bins. See bins (p. 128).

Csplines The smooth csplines option connects consecutive points by natural cubic splines after rendering
the data monotonic on x (see smooth unique (p. 133)). The smoothed curve always passes through thedata points, so closely-spaced points may generate local bumps and excursions in the smoothed curve.
splot ... smooth csplines with lines fits splines to the x, y, and z coordinates of successive data points.
Unlike 2D csplines, the points are not sorted first so it is possible to fit splines to a trajectory containing
loops. In the general case three separate sets of spline coefficients are generated, each treating one coordinate
x, y, or z as a function of a shared implicit trajectory path parameter. This is equivalent to the 2D plot ...
smooth path option.
In the special case that the curve lies in the xz, yz, or xy plane then only a single set of spline coefficientsis generated. This allows you to generate a stack of smoothed curves in 3D where each one replicates the
spline fit you would have obtained from a 2D plot of the coordinates in projection.
Mcsplines The smooth mcsplines option connects consecutive points by cubic splines constrained suchthat the smoothed function preserves the monotonicity and convexity of the original data points. This
reduces the effect of outliers. FN Fritsch & RE Carlson (1980) "Monotone Piecewise Cubic Interpolation",
SIAM Journal on Numerical Analysis 17: 238–246.
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The smooth path option generates cubic splines to fit
points in the order they are presented in the input data;
i.e. they are not first sorted on x. This generates asmooth path with filledcurves closed
smooth path with lines
smooth spline through a closed curve or along a traoriginal points
jectory that contains loops. This smoothing mode issupported for both 2D and 3D plot commands. A separate curve is created for each set of points in the input file, where a blank line separates the sets. Plottingsmooth path with filledcurves closed will guaranteethat each set of points creates a closed curve. Plottingsmooth path with lines will generate a closed curve
if the first and last points in the set overlap, otherwise it will create an open-ended smooth path. Seesmooth path.dem
Sbezier The smooth sbezier option first renders the data monotonic (unique) and then applies thebezier algorithm.
Unique The smooth unique option makes the data monotonic in x; points with the same x-value are
replaced by a single point having the average y-value. The resulting points are then connected by straightline segments.
Unwrap The smooth unwrap option modifies the input data so that any two successive points will notdiffer by more than pi; a point whose y value is outside this range will be incremented or decremented bymultiples of 2pi until it falls within pi of the previous point. This operation is useful for making wrapped
phase measurements continuous over time.
Frequency The smooth frequency option makes the data monotonic in x; points with the same x-value
are replaced by a single point having the summed y-values. To plot a histogram of the number of data values
in equal size bins, set the y-value to 1.0 so that the sum is a count of occurrences in that bin. This is done
implicitly if only a single column is provided. Example:
binwidth = <something> # set width of x values in each binbin(val) = binwidth * floor(val/binwidth)
plot "datafile" using (bin(column(1))):(1.0) smooth frequency
plot "datafile" using (bin(column(1))) smooth frequency # same result

See also smooth.dem
Fnormal The smooth fnormal option work just like the frequency option, but produces a normalized
histogram. It makes the data monotonic in x and normalises the y-values so they all sum to 1. Points withthe same x-value are replaced by a single point containing the sumed y-values. To plot a histogram of thenumber of data values in equal size bins, set the y-value to 1.0 so that the sum is a count of occurrences inthat bin. This is done implicitly if only a single column is provided. See also smooth.dem
Cumulative The smooth cumulative option makes the data monotonic in x; points with the same xvalue are replaced by a single point containing the cumulative sum of y-values of all data points with lower
x-values (i.e. to the left of the current data point). This can be used to obtain a cumulative distributionfunction from data. See also smooth.dem
Cnormal The smooth cnormal option makes the data monotonic in x and normalises the y-values onto
the range [0:1]. Points with the same x-value are replaced by a single point containing the cumulative sumof y-values of all data points with lower x-values (i.e. to the left of the current data point) divided by the

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total sum of all y-values. This can be used to obtain a normalised cumulative distribution function fromdata (useful when comparing sets of samples with differing numbers of members). See also smooth.dem
Kdensity The smooth kdensity option generates and plots a kernel density estimate using Gaussian
kernels for the distribution from which a set of values was drawn. Values are taken from the first data
column, optional weights are taken from the second column. A Gaussian is placed at the location of eachpoint and the sum of all these Gaussians is plotted as a function. To obtain a normalized histogram, eachweight should be 1/number-of-points.
Bandwidth: By default gnuplot calculates and uses the bandwidth which would be optimal for normally
distributed data values.
default_bandwidth = sigma * (4/3N) ** (0.2)

This will usually be a very conservative, i.e. broad bandwidth. Alternatively, you can provide an explicit
bandwidth.
plot $DATA smooth kdensity bandwidth <value> with boxes

The bandwidth used in the previous plot is stored in GPVAL KDENSITY BANDWIDTH.
Period: For periodic data individual Gaussian components should be treated as repeating at intervals of one
period. One example is data measured as a function of angle, where the period is 2pi. Another example isdata indexed by day-of-year and measured over multiple years, where the period is 365. In such cases theperiod should be provided in the plot command:plot $ANGULAR_DAT smooth kdensity period 2*pi with lines

Special-filenames
There are a few filenames that have a special meaning: ’ ’, ’-’, ’+’ and ’++’.
The empty filename ’ ’ tells gnuplot to re-use the previous input file in the same plot command. So to plot
two columns from the same input file:plot 'filename' using 1:2, '' using 1:3

The filename can also be reused over subsequent plot commands, however save then only records the namein a comment.
The special filenames ’+’ and ’++’ are a mechanism to allow the full range of using specifiers and plot styles
with inline functions. Normally a function plot can only have a single y (or z) value associated with eachsampled point. The pseudo-file ’+’ treats the sampled points as column 1, and allows additional column
values to be specified via a using specification, just as for a true input file. The number of samples iscontrolled via set samples or by giving an explicit sampling interval in the range specifier. Samples are
generated over the range given by set trange if it has been set, otherwise over the full range of set xrange.
Note: The use of trange is a change from some earlier gnuplot versions. It allows the sampling range todiffer from the x axis range.
plot '+' using ($1):(sin($1)):(sin($1)**2) with filledcurves

An independent sampling range can be provided immediately before the ’+’. As in normal function plots,
a name can be assigned to the independent variable. If given for the first plot element, the sampling range
specifier has to be preceded by the sample keyword (see also plot sampling (p. 140)).
plot sample [beta=0:2*pi] '+' using (sin(beta)):(cos(beta)) with lines

Here is an example where the sampling interval (1.5) is given as part of the sampling range. Samples will
be generated at -3, -1.5, 0, 1.5, ..., 24.
plot $MYDATA, [t=-3:25:1.5] '+' using (t):(f(t))

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The pseudo-file ’++’ returns 2 columns of data forming a regular grid of [u,v] coordinates with the numberof points along u controlled by set samples and the number of points along v controlled by set isosamples.
You must set urange and vrange before plotting ’++’. However the x and y ranges can be autoscaled or canbe explicitly set to different values than urange and vrange. Examples:
splot '++' using 1:2:(sin($1)*sin($2)) with pm3d
plot '++' using 1:2:(sin($1)*sin($2)) with image

The special filename ’-’ specifies that the data are inline; i.e., they follow the command. Only the data
follow the command; plot options like filters, titles, and line styles remain on the plot command line. Thisis similar to << in unix shell script. The data are entered as though they were being read from a file, onedata point per record. The letter "e" at the start of the first column terminates data entry.
’-’ is intended for situations where it is useful to have data and commands together, e.g. when both are
piped to gnuplot from another application. Some of the demos, for example, might use this feature. Whileplot options such as index and every are recognized, their use forces you to enter data that won’t be used.
For all but the simplest cases it is probably easier to first define a datablock and then read from it rather
than from ’-’. See datablocks (p. 55).
If you use ’-’ with replot, you may need to enter the data more than once. See replot (p. 147), refresh(p. 146). Here again it may be better to use a datablock.
A blank filename (’ ’) specifies that the previous filename should be reused. This can be useful with things
likeplot 'a/very/long/filename' using 1:2, '' using 1:3, '' using 1:4

If you use both ’-’ and ’ ’ on the same plot command, you’ll need to provide two sets of inline data. It will
not reuse the first one.
Piped-data
On systems with a popen function, the datafile can be piped through a shell command by starting the filename with a ’<’. For example,
pop(x) = 103*exp(-x/10)
plot "< awk '{print $1-1965, $2}' population.dat", pop(x)would plot the same information as the first population example but with years since 1965 as the x axis. If
you want to execute this example, you have to delete all comments from the data file above or substitutethe following command for the first part of the command above (the part up to the comma):
plot "< awk '$0 !~ /^#/ {print $1-1965, $2}' population.dat"

While this approach is most flexible, it is possible to achieve simple filtering with the using keyword.
On systems with an fdopen() function, data can be read from an arbitrary file descriptor attached to either
a file or pipe. To read from file descriptor n use ’<&n’. This allows you to easily pipe in several data files
in a single call from a POSIX shell:$ gnuplot -p -e "plot '<&3', '<&4'" 3<data-3 4<data-4$ ./gnuplot 5< <(myprogram -with -options)gnuplot> plot '<&5'Using
The most common datafile modifier is using. It tells the program which columns of data in the input file
are to be plotted.
Syntax:plot 'file' using <entry> {:<entry> {:<entry> ...}} {'format'}

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Each <entry> may be a simple column number that selects the value from one field of the input file, a stringthat matches a column label in the first line of a data set, an expression enclosed in parentheses, or a special
function not enclosed in parentheses such as xticlabels(2).
If the entry is an expression in parentheses, then the function column(N) may be used to indicate the value
in column N. That is, column(1) refers to the first item read, column(2) to the second, and so on. The
special symbols $1, $2, ... are shorthand for column(1), column(2) ...
The special symbol $# evaluates to the total number of columns in the current line of input, so column($#)
or stringcolumn($#) always returns the content of the final column even if the number of columns is unknown
or different lines in the file contain different numbers of columns.
The function valid(N) tests whether column N contains a valid number. It returns 0 if the column value
is missing, uninterpretable, or NaN. If each column of data in the input file contains a label in the first row
rather than a data value, this label can be used to identify the column on input and/or in the plot legend.
The column() function can be used to select an input column by label rather than by column number. For
example, if the data file contains
Heightval1...

Weight
val1
...

Age
val1
...

then the following plot commands are all equivalentplot 'datafile' using 3:1, '' using 3:2
plot 'datafile' using (column("Age")):(column(1)), \'' using (column("Age")):(column(2))
plot 'datafile' using "Age":"Height", '' using "Age":"Weight"

The full string must match. Comparison is case-sensitive. To use column labels in the plot legend, use set
key autotitle columnhead or use function columnhead(N) when specifying an individual title.
In addition to the actual columns 1...N in the input data file, gnuplot presents data from several "pseudocolumns" that hold bookkeeping information. E.g. $0 or column(0) returns the sequence number of thisdata record within a dataset. Please see pseudocolumns (p. 137).
An empty <entry> will default to its order in the list of entries. For example, using ::4 is interpreted asusing 1:2:4.
If the using list has only a single entry, that <entry> will be used for y and the data point number (pseudocolumn $0) is used for x; for example, "plot ’file’ using 1" is identical to "plot ’file’ using 0:1". If theusing list has two entries, these will be used for x and y. See set style (p. 214) and fit (p. 105) for details
about plotting styles that make use of data from additional columns of input.
Format If a format is specified, it is used to read in each datafile record using the C library ’scanf’ function.
Otherwise the record is interpreted as consisting of columns (fields) of data separated by whitespace (spaces
and/or tabs), but see datafile separator (p. 162).
’scanf’ itself accepts several numerical specifications but gnuplot requires all inputs to be double-precision
floating-point variables, so "%lf" is essentially the only permissible specifier. The format string must containat least one such input specifier and no more than seven of them. ’scanf’ expects to see white space – ablank, tab ("\t"), newline ("\n"), or formfeed ("\f") – between numbers; anything else in the input stream
must be explicitly skipped.
Note that the use of "\t", "\n", or "\f" requires use of double-quotes rather than single-quotes.
Using examples This creates a plot of the sum of the 2nd and 3rd data against the first: The format string
specifies comma- rather than space-separated columns. The same result could be achieved by specifying set
datafile separator comma.
plot 'file' using 1:($2+$3) '%lf,%lf,%lf'

In this example the data are read from the file "MyData" using a more complicated format:

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plot 'MyData' using "%*lf%lf%*20[^\n]%lf"

The meaning of this format is:%*lf%lf%*20[^\n]%lf

ignore a number
read a double-precision number (x by default)
ignore 20 non-newline characters
read a double-precision number (y by default)

One trick is to use the ternary ?: operator to filter data:plot 'file' using 1:($3>10 ? $2 : 1/0)

which plots the datum in column two against that in column one provided the datum in column three exceeds
ten. 1/0 is undefined; gnuplot quietly ignores undefined points, so unsuitable points are suppressed. Or
you can use the pre-defined variable NaN to achieve the same result.
In fact, you can use a constant expression for the column number, provided it doesn’t start with an opening
parenthesis; constructs like using 0+(complicated expression) can be used. The crucial point is thatthe expression is evaluated once if it doesn’t start with a left parenthesis, or once for each data point read
if it does.
If timeseries data are being used, the time can span multiple columns. The starting column should bespecified. Note that the spaces within the time must be included when calculating starting columns forother data. E.g., if the first element on a line is a time with an embedded space, the y value should bespecified as column three.
It should be noted that (a) plot ’file’, (b) plot ’file’ using 1:2, and (c) plot ’file’ using ($1):($2) canbe subtly different. See missing (p. 162).
It is often possible to plot a file with lots of lines of garbage at the top simply by specifying
plot 'file' using 1:2

However, if you want to leave text in your data files, it is safer to put the comment character (#) in the firstcolumn of the text lines.
Pseudocolumns Expressions in the using clause of a plot statement can refer to additional bookkeeping
values in addition to the actual data values contained in the input file. These are contained in "pseudocolumns".
column(0)column(-1)

column(-2)

column($#)

The sequential order of each point within a data set.
The counter starts at 0, increments on each non-blank,
non-comment line, and is reset by two sequential blankrecords. For data in non-uniform matrix format, column(0)is the linear order of each matrix element.
The shorthand form $0 is available.
This counter starts at 0, increments on a single blank line,
and is reset by two sequential blank lines.
This corresponds to the data line in array or grid data.
It can also be used to distinguish separate line segmentsor polygons within a data set.
Starts at 0 and increments on two sequential blank lines.
This is the index number of the current data set within afile that contains multiple data sets. See `index`.
The special symbol $# evaluates to the total number ofcolumns available, so column($#) refers to the last(rightmost) field in the current input line.
column($# - 1) would refer to the last-but-one column, etc.

Arrays When the data source being plotted is an array or array-valued function, the "columns" in a using
specification are interpreted as below. See arrays (p. 52) for more detail.
column 1
column 2
column 3

the array index
the real component of a numerical array entry
or the string value of a string array entry
the imaginary part of a numerical array entry

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Key The layout of certain plot styles (column-stacked histograms, spider plots) is such that it would makeno sense to generate plot titles from a data column header. Also it would make no sense to generate axis tic
labels from the content of a data column (e.g. using 2:3:xticlabels(1)). These plots styles instead use theform using 2:3:key(1) to generate plot titles for the key from the text content of a data column, usually afirst column of row headers. See the example given for spiderplot (p. 93).
Xticlabels Axis tick labels can be generated via a string function, usually taking a data column as anargument. The simplest form uses the data column itself as a string. That is, xticlabels(N) is shorthand for
xticlabels(stringcolumn(N)). This example uses the contents of column 3 as x-axis tick labels.
plot 'datafile' using <xcol>:<ycol>:xticlabels(3) with <plotstyle>

Axis tick labels may be generated for any of the plot axes: x x2 y y2 z. The ticlabels(<labelcol>) specifiersmust come after all of the data coordinate specifiers in the using portion of the command. For each data
point which has a valid set of X,Y[,Z] coordinates, the string value given to xticlabels() is added to the listof xtic labels at the same X coordinate as the point it belongs to. xticlabels() may be shortened to xtic()
and so on.
Example:splot "data" using 2:4:6:xtic(1):ytic(3):ztic(6)In this example the x and y axis tic labels are taken from different columns than the x and y coordinate
values. The z axis tics, however, are generated from the z coordinate of the corresponding point.
Example:plot "data" using 1:2:xtic( $3 > 10. ? "A" : "B" )This example shows the use of a string-valued function to generate x-axis tick labels. Each point in the data
file generates a tick mark on x labeled either "A" or "B" depending on the value in column 3.
X2ticlabels

See plot using xticlabels (p. 138).

Yticlabels

See plot using xticlabels (p. 138).

Y2ticlabels

See plot using xticlabels (p. 138).

Zticlabels

See plot using xticlabels (p. 138).

Volatile
The volatile keyword in a plot command indicates that the data previously read from the input stream orfile may not be available for re-reading. This tells the program to use refresh rather than replot commands
whenever possible. See refresh (p. 146).

Functions
Built-in or user-defined functions can be displayed by the plot and splot commands in addition to, or insteadof, data read from a file. The requested function is evaluated by sampling at regular intervals spanning theindependent axis range[s]. See set samples (p. 213) and set isosamples (p. 174). Example:
approx(ang) = ang - ang**3 / (3*2)
plot sin(x) title "sin(x)", approx(x) title "approximation"

To set a default plot style for functions, see set style function (p. 218). For information on built-infunctions, see expressions functions (p. 39). For information on defining your own functions, see userdefined (p. 52).

gnuplot 6.0

139

Parametric
When in parametric mode (set parametric) mathematical expressions must be given in pairs for plot andin triplets for splot.
Examples:plot sin(t),t**2
splot cos(u)*cos(v),cos(u)*sin(v),sin(u)Data files are plotted as before, except any preceding parametric function must be fully specified before adata file is given as a plot. In other words, the x parametric function (sin(t) above) and the y parametricfunction (t**2 above) must not be interrupted with any modifiers or data functions; doing so will generate
a syntax error stating that the parametric function is not fully specified.
Other modifiers, such as with and title, may be specified only after the parametric function has been
completed:plot sin(t),t**2 title 'Parametric example' with linespoints

See also Parametric Mode Demos.

RangesThis section describes only the optional axis ranges that may appear as the very first items in a plot or splot
command. If present, these ranges override any range limits established by a previous set range statement.
For optional ranges elsewhere in a plot command that limit sampling of an individual plot component, seesampling (p. 140).
Syntax:[{<dummy-var>=}{{<min>}:{<max>}}][{{<min>}:{<max>}}]

The first form applies to the independent variable (xrange or trange, if in parametric mode). The second
form applies to dependent variables. <dummy-var> optionally establishes a new name for the independent
variable. (The default name may be changed with set dummy.)
In non-parametric mode, ranges must be given in the orderplot [<xrange>][<yrange>][<x2range>][<y2range>] ...

In parametric mode, ranges must be given in the orderplot [<trange>][<xrange>][<yrange>][<x2range>][<y2range>] ...

The following plot command shows setting trange to [-pi:pi], xrange to [-1.3:1.3] and yrange to [-1:1] forthe duration of the graph:plot [-pi:pi] [-1.3:1.3] [-1:1] sin(t),t**2* can be used to allow autoscaling of either of min and max. Use an empty range [] as a placeholder ifnecessary.
Ranges specified on the plot or splot command line affect only that one graph; use the set xrange, set
yrange, etc., commands to change the default ranges for future graphs.
The use of on-the-fly range specifiers in a plot command may not yield the expected result for linked axes
(see set link (p. 183)).
For time data you must provide the range in quotes, using the same format used to read time from thedatafile. See set timefmt (p. 225).
Examples:This uses the current ranges:
plot cos(x)140

gnuplot 6.0

This sets the x range only:
plot [-10:30] sin(pi*x)/(pi*x)

This is the same, but uses t as the dummy-variable:
plot [t = -10 :30]

sin(pi*t)/(pi*t)

This sets both the x and y ranges:
plot [-pi:pi] [-3:3]

tan(x), 1/xThis sets only the y range:plot [ ] [-2:sin(5)*-8] sin(x)**besj0(x)This sets xmax and ymin only:
plot [:200] [-pi:]$mydata using 1:2

This sets the x range for a timeseries:
set timefmt "%d/%m/%y %H:%M"
plot ["1/6/93 12:00":"5/6/93 12:00"] 'timedata.dat'

Sampling
1D sampling (x or t axis)
By default, computed functions are sampled over the entire range of the plot as set by a prior set xrange
command, by an x-axis range specifier at the very start of the plot command, or by autoscaling the xrange
to span data seen in all the elements of this plot. Points generated by the pseudo-file "+" are sampled overthe current range of the t axis, which may or may not be the same as the range of the x axis.
Individual plot components can be assigned a more restricted sampling range.
Examples:This establishes a total range on x running from 0 to 1000 and then plots data from a file and two functions
each spanning a portion of the total range:
set xrange [0:1000]
plot 'datafile', [0:200] func1(x), [200:500] func2(x)This is similar except that the total range is established by the contents of the data file. In this case thesampled functions may or may not be entirely contained in the plot:
set autoscale x
plot 'datafile', [0:200] func1(x), [200:500] func2(x)The plot command below is ambiguous. The initial range [0:10] will be interpreted as applying to theentire plot, overriding the previous xrange command, rather than applying solely to the sampling of the firstfunction as was probably the intent:
set xrange [0:50]
plot [0:10] f(x), [10:20] g(x), [20:30] h(x)To remove the ambiguity in the previous example, insert the keyword sample to indicate that [0:10] is asampling range applied to a single plot component rather than a global x-axis range that would apply to theentire plot.
plot sample [0:10] f(x), [10:20] g(x), [20:30] h(x)This example shows one way of tracing out a helix in a 3D plot
set xrange [-2:2]; set yrange [-2:2]
splot sample [h=1:10] '+' using (cos(h)):(sin(h)):(h)gnuplot 6.0

141

2D sampling (u and v axes)
Computed functions or data generated for the pseudo-file ’++’ use samples generated along the u and v
axes. See special-filenames ++ (p. 134). 2D sampling can be used in either plot or splot commands.
Example of 2D sampling in a 2D plot command. These commands generated the plot shown for plotstylewith vectors. See vectors (p. 95).
set urange [ -2.0 : 2.0 ]set vrange [ -2.0 : 2.0 ]plot '++' using ($1):($2):($2*0.4):(-$1*0.4) with vectors

Example of 2D sampling in a 3D splot command. These commands are similar to the ones used in sampling.dem. Note that the two surfaces are sampled over u and v ranges smaller than the full x and y rangesof the resulting plot.
set title "3D sampling range distinct from plot x/y range"
set xrange [1:100]
set yrange [1:100]
splot sample [u=30:70][v=0:50] '++' using 1:2:(u*v) lt 3, \[u=40:80][v=30:60] '++' using (u):(v):(u*sqrt(v)) lt 4

The range specifiers for sampling on u and v can include an explicit sampling interval to control the number
and spacing of samples:
splot sample [u=30:70:1][v=0:50:5] '++' using 1:2:(func($1,$2))

For loops in plot commandIf many similar files or functions are to be plotted together, it may be convenient to do so by iterating overa shared plot command.
Syntax:plot for [<variable> = <start> : <end> {:<increment>}]
plot for [<variable> in "string of words"]

The scope of an iteration ends at the next comma or the end of the command, whichever comes first. An
exception to this is that definitions are grouped with the following plot item even if there is an intervening
comma. Note that iteration does not work for plots in parametric mode.
Example:plot for [j=1:3] sin(j*x)

Example:plot for [dataset in "apples bananas"] dataset."dat" title dataset

In this example iteration is used both to generate a file name and a corresponding title.
Example:file(n) = sprintf("dataset_%d.dat",n)splot for [i=1:10] file(i) title sprintf("dataset %d",i)This example defines a string-valued function that generates file names, and plots ten such files together.
The iteration variable (’i’ in this example) is treated as an integer, and may be used more than once.
Example:set key left
plot for [n=1:4] x**n sprintf("%d",n)This example plots a family of functions.
Example:142

gnuplot 6.0
list = "apple banana cabbage daikon eggplant"item(n) = word(list,n)plot for [i=1:words(list)] item[i].".dat" title item(i)list = "new stuff"
replotThis example steps through a list and plots once per item. Because the items are retrieved dynamically, you
can change the list and then replot.
Example:list = "apple banana cabbage daikon eggplant"
plot for [i in list] i.".dat" title ilist = "new stuff"
replotThis example does exactly the same thing as the previous example, but uses the string iterator form of thecommand rather than an integer iterator.
If an iteration is to continue until all available data is consumed, use the symbol * instead of an integer<end>. This can be used to process all columns in a line, all datasets (separated by 2 blank lines) in a file,or all files matching a template.
Examples:plot for [file in "A.dat B.dat"] for [column=2:*] file using 1:column
splot for [i=0:*] 'datafile' index i using 1:2:3 with lines
plot for [i=1:*] file=sprintf("File_%03d.dat",i) file using 2 title file

Caveat: You can nest iterations where one is open-ended, as in the first example above. However nesting an
open-ended iteration inside another open-ended iteration is probably not useful, since both will terminate
at the same time when no data is found. The program will issue a warning if this happens.

Title
By default each plot is listed in the key by the corresponding function or file name. You can give an explicit
plot title instead using the title option.
Syntax:title <text> | notitle [<ignored text>]
title columnheader | title columnheader(N){at {beginning|end}} {{no}enhanced}

where <text> is a quoted string or an expression that evaluates to a string. The quotes will not be shownin the key.
There is also an option that will interpret the first entry in a column of input data (i.e. the column header)
as a text field, and use it as the key title. See datastrings (p. 34). This can be made the default by
specifying set key autotitle columnhead.
The line title and sample can be omitted from the key by using the keyword notitle. A null title (title’ ’) is equivalent to notitle. If only the sample is wanted, use one or more blanks (title ’ ’). If notitle isfollowed by a string this string is ignored.
If key autotitles is set (which is the default) and neither title nor notitle are specified the line title is thefunction name or the file name as it appears on the plot command. If it is a file name, any datafile modifiers
specified will be included in the default title.
The layout of the key itself (position, title justification, etc.) can be controlled using set key (p. 175).
The at keyword allows you to place the plot title somewhere outside the auto-generated key box. The title
can be placed immediately before or after the line in the graph itself by using at {beginning|end}. This
option may be useful when plotting with lines but makes little sense for most other styles.
To place the plot title at an arbitrary location on the page, use the form at <x-position>,<y-position>.
By default the position is interpreted in screen coordinates; e.g. at 0.5, 0.5 is always the middle of thegnuplot 6.0

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screen regardless of plot axis scales or borders. The format of titles placed in this way is still affected by key
options. See set key (p. 175).
Examples:This plots y=x with the title ’x’:
plot xThis plots x squared with title "x^2" and file "data.1" with title "measured data":
plot x**2 title "x^2", 'data.1' t "measured data"

Plot multiple columns of data, each of which contains its own title on the first line of the file. Place thetitles after the corresponding lines rather than in a separate key:unset key
set offset 0, graph 0.1
plot for [i=1:4] 'data' using i with lines title columnhead at end

Create a single key area for two separate plots:
set key Left reverse
set multiplot layout 2,2
plot sin(x) with points pt 6 title "Left plot is sin(x)" at 0.5, 0.30
plot cos(x) with points pt 7 title "Right plot is cos(x)" at 0.5, 0.27
unset multiplot

With
Functions and data may be displayed in one of a large number of styles. The with keyword provides themeans of selection.
Syntax:with <style> { {linestyle | ls <line_style>}| {{linetype | lt <line_type>}{linewidth | lw <line_width>}{linecolor | lc <colorspec>}{pointtype | pt <point_type>}{pointsize | ps <point_size>}{arrowstyle | as <arrowstyle_index>}{fill | fs <fillstyle>} {fillcolor | fc <colorspec>}{nohidden3d} {nocontours} {nosurface}{palette}}}

where <style> is one oflines
pointslinespoints
financebars

dots
impulseslabelssurfacesteps
fstepshistepsarrowsboxes
boxerrorbars
boxxyerror
isosurface

boxplot
candlesticks
circleszerrorfill

table

mask

vectors
xerrorbar
xerrorlines
yerrorbar

yerrorlines
xyerrorbars
xyerrorlines
parallelaxesorellipsesfilledcurves
fillsteps

histograms
image
pm3d

rgbalpha
rgbimagepolygonsor

The first group of styles have associated line, point, and text properties. The second group of styles also havefill properties. See fillstyle (p. 217). Some styles have further sub-styles. See plotting styles (p. 71)
for details of each. Two special styles produce no immediate plot. See set table (p. 222) and with mask

144

gnuplot 6.0(p. 89). The table style produces tabular output to a text file or data block. A plot component whose styleis with mask defines a set of polygonal regions that can be used to mask subsequent plot elements.
A default style may be chosen by set style function and set style data.
By default, each function and data file will use a different line type and point type, up to the maximum
number of available types. All terminal drivers support at least six different point types, and re-use them, inorder, if more are required. To see the complete set of line and point types available for the current terminal,
type test (p. 253).
If you wish to choose the line or point type for a single plot, <line type> and <point type> may be specified.
These are positive integer constants (or expressions) that specify the line type and point type to be used forthe plot. Use test to display the types available for your terminal.
You may also scale the line width and point size for a plot by using <line width> and <point size>, which
are specified relative to the default values for each terminal. The pointsize may also be altered globally —see set pointsize (p. 210) for details. But note that both <point size> as set here and as set by set
pointsize multiply the default point size; their effects are not cumulative. That is, set pointsize 2; plot
x with points ps 3 will use points three times the default size, not six.
It is also possible to specify pointsize variable either as part of a line style or for an individual plot. In
this case one extra column of input is required, i.e. 3 columns for a 2D plot and 4 columns for a 3D splot.
The size of each individual point is determined by multiplying the global pointsize by the value read fromthe data file.
If you have defined specific line type/width and point type/size combinations with set style line, one ofthese may be selected by setting <line style> to the index of the desired style.
Both 2D and 3D plots (plot and splot commands) can use colors from a smooth palette set previously withthe command set palette. The color value corresponds to the z-value of the point itself or to a separate
color coordinate provided in an optional additional using column. Color values may be treated either asa fraction of the palette range (palette frac) or as a coordinate value mapped onto the colorbox range(palette or palette z). See colorspec (p. 57), set palette (p. 198), linetypes (p. 56).
The keyword nohidden3d applies only to plots made with the splot command. Normally the global option
set hidden3d applies to all plots in the graph. You can attach the nohidden3d option to any individual
plots that you want to exclude from the hidden3d processing. The individual elements other than surfaces(i.e. lines, dots, labels, ...) of a plot marked nohidden3d will all be drawn, even if they would normally be
obscured by other plot elements.
Similarly, the keyword nocontours will turn off contouring for an individual plot even if the global property
set contour is active.
Similarly, the keyword nosurface will turn off the 3D surface for an individual plot even if the global
property set surface is active.
The keywords may be abbreviated as indicated.
Note that the linewidth, pointsize and palette options are not supported by all terminals.
Examples:This plots sin(x) with impulses:
plot sin(x) with impulses

This plots x with points, x**2 with the default:
plot x w points, x**2

This plots tan(x) with the default function style, file "data.1" with lines:
plot tan(x), 'data.1' with lThis plots "leastsq.dat" with impulses:
plot 'leastsq.dat' w iThis plots the data file "population" with boxes:gnuplot 6.0

145

plot 'population' with boxes

This plots "exper.dat" with errorbars and lines connecting the points (errorbars require three or fourcolumns):
plot 'exper.dat' w lines, 'exper.dat' notitle w errorbars

Another way to plot "exper.dat" with errorlines (errorbars require three or four columns):
plot 'exper.dat' w errorlines

This plots sin(x) and cos(x) with linespoints, using the same line type but different point types:
plot sin(x) with linesp lt 1 pt 3, cos(x) with linesp lt 1 pt 4This plots file "data" with points of type 3 and twice usual size:
plot 'data' with points pointtype 3 pointsize 2This plots file "data" with variable pointsize read from column 4plot 'data' using 1:2:4 with points pt 5 pointsize variableThis plots two data sets with lines differing only by weight:
plot 'd1' t "good" w l lt 2 lw 3, 'd2' t "bad" w l lt 2 lw 1

This plots filled curve of x*x and a color stripe:
plot x*x with filledcurve closed, 40 with filledcurve y=10

This plots x*x and a color box:
plot x*x, (x>=-5 && x<=5 ? 40 : 1/0) with filledcurve y=10 lt 8This plots a surface with color lines:
splot x*x-y*y with line paletteThis plots two color surfaces at different altitudes:
splot x*x-y*y with pm3d, x*x+y*y with pm3d at t

Print
Syntax:print <expression> {, <expression>, ...}The print command prints the value of one or more expressions. Output is to the screen unless it has beenredirected using the set print command. See expressions (p. 36). See also printerr (p. 146).
An <expression> may be any valid gnuplot expression, including numeric or string constants, a function
returning a number or string, an array, or the name of a variable. It is also possible to print a datablock. The
sprintf and gprintf functions can be used in conjunction with print for additional flexibility in formatting
the output.
You can use iteration within a print command to include multiple values on a single line of output.
Examples:print 123 + 456
print sinh(pi/2)
print "rms of residuals (FIT_STDFIT) is ", FIT_STDFIT
print sprintf("rms of residuals is %.3f after fit", FIT_STDFIT)
print "Array A: ", Aprint "Individual elements of array A: ", for [i=1:|A|] A[i]print $DATA

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Printerr
printerr is the same as print except that output is always sent to stderr even while redirection from a prior
set print command remains in effect. Use the warn command instead if you want the output to include
the current filename (or function block name) and line number.

Pwd
The pwd command prints the name of the working directory to the screen.
Note that if you wish to store the current directory into a string variable or use it in string expressions, then
you can use variable GPVAL PWD, see show variables all (p. 245).

Quit
quit is a synonym for the exit command. See exit (p. 105).

Raise
Syntax:raise {plot_window_id}
lower {plot_window_id}

The raise and lower commands function for only a few terminal types and may depend also on your window
manager and display preference settings.
set term wxt 123
plot $FOO
lower
set term wxt 456
plot $BAZ
raise 123

# create first plot window# lower the only plot window that exists so far# create 2nd plot window may occlude the first one# raise first plot window

These commands are known to be unreliable.

RefreshThe refresh command is similar to replot, with two major differences. refresh reformats and redraws
the current plot using the data already read in. This means that you can use refresh for plots with inline
data (pseudo-device ’-’) and for plots from datafiles whose contents are volatile. You cannot use the refreshcommand to add new data to an existing plot.
Mousing operations, in particular zoom and unzoom, will use refresh rather than replot if appropriate.
Example:plot 'datafile' volatile with lines, '-' with labels
100 200 "Special point"e# Various mousing operations go here
set title "Zoomed in view"
set term post
set output 'zoom.ps'
refreshgnuplot 6.0

147

Remultiplot
remultiplot replays a sequence of commands that were previously stored into the datablock named $GPVAL LAST MULTIPLOT during generation of the previous multiplot. See new multiplots (p. 27).
EXPERIMENTAL: remultiplot is invoked implicitly from replot if the immediately preceeding plot command was part of a completed multiplot. remultiplot is also invoked by hot keys and mouse operations
pan/zoom etc. while a multiplot is displayed.

Replot
The replot command without arguments repeats the last plot or splot command. This can be useful forviewing a plot with different set options, or when generating the same plot for several devices.
Arguments specified after a replot command will be added onto the last plot or splot command (withan implied ’,’ separator) before it is repeated. replot accepts the same arguments as the plot and splot
commands except that ranges cannot be specified. Thus you can use replot to plot a function against thesecond axes if the previous command was plot but not if it was splot.
Note:
plot '-' ; ... ; replot

is not recommended, because it will require that you type in the data all over again. In most cases you can
use the refresh command instead, which will redraw the plot using the data previously read in.
See also command-line-editing (p. 32) for ways to edit the last plot (p. 120) (splot (p. 245)) command.
See also show plot (p. 245) to show the whole current plotting command, and the possibility to copy it
into the history (p. 116).
In previous gnuplot versions, a complete multiplot could not be redrawn. The replot command reproduced
only the final component plot of the full set. In gnuplot version 6 the commands used to generate a multiplot
are stored into a datablock $GPVAL LAST MULTIPLOT. They can be replayed to regenerate the entire
multiplot using the new command remultiplot.
EXPERIMENTAL (details may change in a subsequent gnuplot version): If the previously drawn plot waspart of a multiplot, the replot command is now automatically treated as remultiplot. Several caveats
apply. See new multiplots (p. 27), remultiplot (p. 147), set mouse multiplot (p. ??).

Reread[DEPRECATED in version 5.4]
This command is deprecated in favor of explicit iteration. See iterate (p. 56). The reread command causes
execution from the current gnuplot input file, as specified by a load command, to immediately restart fromthe beginning of the file. This essentially implements an endless loop of commands from the beginning of
the file to the reread command. reread has no effect when reading commands from stdin.

Reset
reset {bind | errors | session}

The reset command causes all graph-related options that can be set with the set command to return totheir default values. This command can be used to restore the default settings after executing a loaded
command file, or to return to a defined state after lots of settings have been changed.
The following are not affected by reset:

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gnuplot 6.0`set term` `set output` `set loadpath` `set linetype` `set fit`
`set encoding` `set decimalsign` `set locale` `set psdir``set overflow` `set multiplot`

Note that reset does not necessarily return settings to the state they were in at program entry, because thedefault values may have been altered by commands in the initialization files gnuplotrc, $HOME/.gnuplot,
or $XDG CONFIG HOME/gnuplot/gnuplotrc. However, these commands can be re-executed by using thevariant command reset session.
reset session deletes any user-defined variables and functions, restores default settings, andthen re-executes the system-wide gnuplotrc initialization file and any private $HOME/.gnuplot or$XDG CONFIG HOME/gnuplot/gnuplotrc preferences file. See initialization (p. 64).
reset errors clears only the error state variables GPVAL ERRNO and GPVAL ERRMSG.
reset bind restores all hotkey bindings to their default state.

ReturnSyntax:return <expression>

The return command acts the same way as the exit and quit commands in that it terminates executionof the current code block or input stream. The return value is meaningful only in the context of executing
code in a function block. See function blocks (p. 114).
Example:function $myfun << EOF
local result = 0
if (error-condition) { return -1 }... body of function ...
return result
EOF

Save
Syntax:save{functions | variables | terminal | set | fit | datablocks}'<filename>' {append}

If no option is specified, gnuplot saves functions, user variables, set options and the most recent plot or
splot command. The current status of set term and set output is written as a comment.
Saved files are written in text format and may be read by the load command.
save terminal will write out just the terminal status, without the comment marker in front of it. This ismainly useful for switching the terminal setting for a short while, and getting back to the previously set
terminal, afterwards, by loading the saved terminal status. Note that for a single gnuplot session you may
rather use the other method of saving and restoring current terminal by the commands set term push andset term pop, see set term (p. 223).
save variables writes all user variables but not datablocks and not internal variables GPVAL * GPFUN *MOUSE * ARG*.
save fit saves only the variables used in the most recent fit command. The saved file may be used as aparameter file to initialize future fit commands using the via keyword.
The filename must be enclosed in quotes.
The special filename "-" may be used to save commands to standard output. On systems which support
a popen function (Unix), the output of save can be piped through an external program by starting thegnuplot 6.0

149

file name with a ’|’. This provides a consistent interface to gnuplot’s internal settings to programs which
communicate with gnuplot through a pipe. Please see help for batch/interactive (p. 31) for more details.
Examples:save 'work.gnu'
save functions 'func.dat'
save var 'state.dat'; save datablocks 'state.dat' append
save set 'options.dat'
save term 'myterm.gnu'
save '-'
save '|grep title >t.gp'

Set-show
The set command can be used to set lots of options. No new graph is drawn, however, until a plot, splot,
or replot command is given.
For most options the corresponding show command reports the current setting. A few show commands
like show palette and show colornames are documented separately.
Options changed using set can be returned to the default state by giving the corresponding unset command.
See also the reset (p. 147) command, which returns all settable parameters to default values.
The set and unset commands may optionally contain an iteration clause. See plot for (p. 141).

AnglesBy default, gnuplot assumes the independent variable in polar graphs is in units of radians. If set angles
degrees is specified before set polar, then the default range is [0:360] and the independent variable hasunits of degrees. This is particularly useful for plots of data files. The angle setting also applies to 3D
mapping as set via the set mapping command.
Syntax:set angles {degrees | radians}show angles

The angle specified in set grid polar is also read and displayed in the units specified by set angles.
set angles also affects the arguments of the machine-defined functions sin(x), cos(x) and tan(x), and theoutputs of asin(x), acos(x), atan(x), atan2(x), and arg(x). It has no effect on the arguments of hyperbolic
functions or Bessel functions. However, the output arguments of inverse hyperbolic functions of complex
arguments are affected; if these functions are used, set angles radians must be in effect to maintainconsistency between input and output arguments.
x={1.0,0.1}
set angles radians
y=sinh(x)print y#prints {1.16933, 0.154051}
print asinh(y) #prints {1.0, 0.1}

but
set angles degrees
y=sinh(x)print y#prints {1.16933, 0.154051}
print asinh(y) #prints {57.29578, 5.729578}

See also poldat.dem:

polar plot using set angles demo.

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gnuplot 6.0

Arrow
Arbitrary arrows can be placed on a plot using the set arrow command.
Syntax:set arrow {<tag>} from <position> to <position>
set arrow {<tag>} from <position> rto <position>
set arrow {<tag>} from <position> length <coord> angle <ang>
set arrow <tag> arrowstyle | as <arrow_style>
set arrow <tag> {nohead | head | backhead | heads}{size <headlength>,<headangle>{,<backangle>}} {fixed}{filled | empty | nofilled | noborder}{front | back}{linestyle | ls <line_style>}{linetype | lt <line_type>}{linewidth | lw <line_width>}{linecolor | lc <colorspec>}{dashtype | dt <dashtype>}
unset arrow {<tag>}show arrow {<tag>}<tag> is an integer that identifies the arrow. If no tag is given, the lowest unused tag value is assigned
automatically. The tag can be used to delete or change a specific arrow. To change any attribute of an
existing arrow, use set arrow with the appropriate tag and specify the attributes to be changed.
The position of the first end point of the arrow is always specified by "from". The other end point canbe specified using any of three different mechanisms. The <position>s are specified by either x,y or x,y,z,
and may be preceded by first, second, graph, screen, or character to select the coordinate system.
Unspecified coordinates default to 0. See coordinates (p. 33) for details. A coordinate system specifier
does not carry over from the first endpoint description the second.
1) "to <position>" specifies the absolute coordinates of the other end.
2) "rto <position>" specifies an offset to the "from" position. For linear axes, graph and screen coordinates,
the distance between the start and the end point corresponds to the given relative coordinate. For logarithmic
axes, the relative given coordinate corresponds to the factor of the coordinate between start and end point.
Thus, a negative relative value or zero are not allowed for logarithmic axes.
3) "length <coordinate> angle <angle>" specifies the orientation of the arrow in the plane of the graph.
Again any of the coordinate systems can be used to specify the length. The angle is always in degrees.
Other characteristics of the arrow can either be specified as a pre-defined arrow style or by providing themin set arrow command. For a detailed explanation of arrow characteristics, see arrowstyle (p. 215).
Examples:To set an arrow pointing from the origin to (1,2) with user-defined linestyle 5, use:
set arrow to 1,2 ls 5

To set an arrow from bottom left of plotting area to (-5,5,3), and tag the arrow number 3, use:
set arrow 3 from graph 0,0 to -5,5,3

To change the preceding arrow to end at 1,1,1, without an arrow head and double its width, use:
set arrow 3 to 1,1,1 nohead lw 2

To draw a vertical line from the bottom to the top of the graph at x=3, use:
set arrow from 3, graph 0 to 3, graph 1 nohead

To draw a vertical arrow with T-shape ends, use:
set arrow 3 from 0,-5 to 0,5 heads size screen 0.1,90

To draw an arrow relatively to the start point, where the relative distances are given in graph coordinates,use:gnuplot 6.0

151

set arrow from 0,-5 rto graph 0.1,0.1

To draw an arrow with relative end point in logarithmic x axis, use:
set logscale x
set arrow from 100,-5 rto 10,10This draws an arrow from 100,-5 to 1000,5. For the logarithmic x axis, the relative coordinate 10 means"factor 10" while for the linear y axis, the relative coordinate 10 means "difference 10".
To delete arrow number 2, use:
unset arrow 2

To delete all arrows, use:
unset arrow

To show all arrows (in tag order), use:show arrow

arrows demos.

Autoscale
Autoscaling may be set individually on the x, y or z axis or globally on all axes. The default is to autoscale
all axes. If you want to autoscale based on a subset of the plots in the figure, you can mark the ones to beomitted with the flag noautoscale in the plot command. See datafile (p. 124).
Syntax:set autoscale {<axis>{|min|max|fixmin|fixmax|fix} | fix | keepfix}
set autoscale noextend
unset autoscale {<axis>}
show autoscale

where <axis> is x, y, z, cb, x2, y2, xy, or paxis <p>. Appending min or max to the axis name tells
gnuplot to autoscale only the minimum or maximum of that axis.
If no axis name is given, all axes are autoscaled.
Autoscaling the independent axes (x for plot and x,y for splot) adjusts the axis range to match the data
being plotted. If the plot contains only functions (no input data), autoscaling these axes has no effect.
Autoscaling the dependent axis (y for a plot and z for splot) adjusts the axis range to match the data orfunction being plotted.
Adjustment of the axis range includes extending it to the next tic mark; i.e. unless the extreme data
coordinate exactly matches a tic mark, there will be some blank space between the data and the plot border.
Addition of this extra space can be suppressed by noextend. It can be further increased by the commandset offset. Please see set xrange (p. 233) and set offsets (p. 196) for additional information.
The behavior of autoscaling remains consistent in parametric mode, (see set parametric (p. 203)). However, there are more dependent variables and hence more control over x, y, and z axis scales. In parametricmode, the independent or dummy variable is t for plots and u,v for splots. autoscale in parametric mode,
then, controls all ranges (t, u, v, x, y, and z) and allows x, y, and z to be fully autoscaled.
When tics are displayed on second axes but no plot has been specified for those axes, x2range and y2range
are inherited from xrange and yrange. This is done before applying offsets or autoextending the ranges toa whole number of tics, which can cause unexpected results. To prevent this you can explicitly link thesecondary axis range to the primary axis range. See set link (p. 183).

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Noextend
set autoscale noextend

By default autoscaling sets the axis range limits to the nearest tic label position that includes all the plot
data. Keywords fixmin, fixmax, fix or noextend tell gnuplot to disable extension of the axis range to thenext tic mark position. In this case the axis range limit exactly matches the coordinate of the most extreme
data point. set autoscale noextend is a synonym for set autoscale fix. Range extension for a single axis
can be disabled by appending the noextend keyword to the corresponding range command, e.g.
set yrange [0:*] noextend

set autoscale keepfix autoscales all axes while leaving the fix settings unchanged.
ExamplesExamples:This sets autoscaling of the y axis (other axes are not affected):
set autoscale yThis sets autoscaling only for the minimum of the y axis (the maximum of the y axis and the other axes are
not affected):
set autoscale yminThis disables extension of the x2 axis tics to the next tic mark, thus keeping the exact range as found in theplotted data and functions:set autoscale x2fixmin
set autoscale x2fixmax

This sets autoscaling of the x and y axes:
set autoscale xy

This sets autoscaling of the x, y, z, x2 and y2 axes:
set autoscaleThis disables autoscaling of the x, y, z, x2 and y2 axes:
unset autoscaleThis disables autoscaling of the z axis only:
unset autoscale z

Polar mode
When in polar mode (set polar), the xrange and the yrange may be left in autoscale mode. If set rrange
is used to limit the extent of the polar axis, then xrange and yrange will adjust to match this automatically.
However, explicit xrange and yrange commands can later be used to make further adjustments. See set
rrange (p. 213).
See also polar demos.

Bindshow bind shows the current state of all hotkey bindings. See bind (p. 61).

Bmargin
The command set bmargin sets the size of the bottom margin. Please see set margin (p. 185) for details.

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Border
The set border and unset border commands control the display of the graph borders for the plot andsplot commands. Note that the borders do not necessarily coincide with the axes; with plot they often do,
but with splot they usually do not.
Syntax:set border {<integer>}{front | back | behind}{linestyle | ls <line_style>}{linetype | lt <line_type>} {linewidth | lw <line_width>}{linecolor | lc <colorspec>} {dashtype | dt <dashtype>}{polar}unset bordershow borderWith a splot displayed in an arbitrary orientation, like set view 56,103, the four corners of the x-y plane
can be referred to as "front", "back", "left" and "right". A similar set of four corners exist for the top surface,of course. Thus the border connecting, say, the back and right corners of the x-y plane is the "bottom rightback" border, and the border connecting the top and bottom front corners is the "front vertical". (Thisnomenclature is defined solely to allow the reader to figure out the table that follows.)
The borders are encoded in a 12-bit integer: the four low bits control the border for plot and the sides ofthe base for splot; the next four bits control the verticals in splot; the four high bits control the edges on
top of an splot. The border settings is thus the sum of the appropriate entries from the following table:

Bit
1
2
4
8
16
32
64
128
256
512
1024
2048
4096

Graph Border Encoding
plot
splot
bottombottom left front
leftbottom left backtopbottom right front
rightbottom right backno effect
left verticalno effect
back verticalno effect
right verticalno effect
front verticalno effect
top left backno effect
top right backno effect
top left front
no effect
top right frontpolar
no effect

The default setting is 31, which is all four sides for plot, and base and z axis for splot.
Separate from the four vertical lines in a 3D border, the splot command by default draws a vertical line
each corner of a surface to the base plane of the plot. These verticals are not controlled by set border.
Instead use set/unset cornerpoles.
In 2D plots the border is normally drawn on top of all plots elements (front). If you want the border to be
drawn behind the plot elements, use set border back.
In hidden3d plots the lines making up the border are normally subject to the same hidden3d processing as
the plot elements. set border behind will override this default.
Using the optional <linestyle>, <linetype>, <linewidth>, <linecolor>, and <dashtype> specifiers, the way
the border lines are drawn can be influenced (limited by what the current terminal driver supports). Besides
the border itself, this line style is used for the tics, independent of whether they are plotted on the border
or on the axes (see set xtics (p. 235)).
For plot, tics may be drawn on edges other than bottom and left by enabling the second axes – see set
xtics (p. 235) for details.

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If a splot draws only on the base, as is the case with "unset surface; set contour base", then the verticals
and the top are not drawn even if they are specified.
The set grid options ’back’, ’front’ and ’layerdefault’ also control the order in which the border lines are
drawn with respect to the output of the plotted data.
The polar keyword enables a circular border for polar plots.
Examples:Draw default borders:set border

Draw only the left and bottom (plot) or both front and back bottom left (splot) borders:set border 3

Draw a complete box around a splot:
set border 4095

Draw a topless box around a splot, omitting the front vertical:
set border 127+256+512 # or set border 1023-128

Draw only the top and right borders for a plot and label them as axes:
unset xtics; unset ytics; set x2tics; set y2tics; set border 12

Boxwidth
The set boxwidth command is used to set the default width of boxes in the boxes, boxerrorbars,
boxplot, candlesticks and histograms styles.
Syntax:set boxwidth {<width>} {absolute|relative}
show boxwidth

By default, adjacent boxes are extended in width until they touch each other. A different default width may
be specified using the set boxwidth command. Relative widths are interpreted as being a fraction of thisdefault width.
An explicit value for the boxwidth is interpreted as being a number of units along the current x axis
(absolute) unless the modifier relative is given. If the x axis is a log-scale (see set log (p. 184)) then thevalue of boxwidth is truly "absolute" only at x=1; this physical width is maintained everywhere along theaxis (i.e. the boxes do not become narrower the value of x increases). If the range spanned by a log scale x
axis is far from x=1, some experimentation may be required to find a useful value of boxwidth.
The default is superseded by explicit width information taken from an extra data column in styles boxes orboxerrorbars. See style boxes (p. 72) and style boxerrorbars (p. 72) for more details.
To set the box width to automatic use the command
set boxwidth

To set the box width to half of the automatic size use
set boxwidth 0.5 relative

To set the box width to an absolute value of 2 use
set boxwidth 2 absolute

Boxdepth
set boxdepth {<y extent>} | square

The set boxdepth command affects only 3D plots created by splot with boxes. It sets the extent of eachbox along the y axis, i.e. its thickness. set boxdepth square will try to choose a y extent that gives theappearance of a square cross section independent of the axis scales on x and y.

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Chi shapes
set chi_shapes fraction <value>
unset chi_shapes

The concave hull filter creates χ-shapes defined by a characteristic length chi length. If no chi length variable
has been set, it chooses a value equal to a fraction of the longest edge in the bounding polygon (the convexhull). The fraction defaults to 0.6 but can be changed using this command. Choosing a value of 1.0 will
reduce the resulting hull to the convex hull. Smaller values will produce increasingly concave hulls. Seeconcavehull (p. 129). The unset chi shapes command restores the fraction to 0.6 and undefines thechi length variable.

Color
Gnuplot assigns each element of a plot or splot command a new set of line properties taken from a predefinedsequence. The default is to distinguish successive lines by a change in color. The alternative selected by set
monochrome uses a sequence of black lines distinguished by linewidth or dot/dash pattern. The set colorcommand exits this alternative monochrome mode and restores the previous set of default color lines. See
set monochrome (p. 186), set linetype (p. 182), and set colorsequence (p. 155).

Colormap
Syntax:set colormap new <colormap-name>set colormap <colormap-name> range [<min>:<max>]
show colormaps

set colormap new <name> creates a colormap array <name> and loads it from the current palettesettings. This saved colormap can be further manipulated as an array of 32-bit ARGB color values and usedby name in subsequent plots.
Here is an example that creates a palette running from dark red to white, saves it to a colormap array named’Reds’, and makes all entries in the colormap partially transparent. This named colormap is then used laterto color a pm3d surface. Note that the alpha channel value in a named colormap follows the convention for
ARGB line properties; i.e 0 is opaque, 0xff is fully transparent.
set palette defined (0 "dark-red", 1 "white")set colormap new Reds
do for [i=1:|Reds|] { Reds[i] = Reds[i] | 0x3F000000 }splot func(x,y) with pm3d fillcolor palette Reds

The mapping of z values onto the colormap can be tuned by setting minimum and maximum z values that
correspond to the end points. For example
set colormap Reds range [0:10]

If no range is set, or if min and max are the same, then the mapping uses the current limits of cbrange. See
set cbrange (p. 243).
A colormap can be used to gradient-fill a rectangular area. See pixmap colormap (p. 204).

Colorsequence
Syntax:set colorsequence {default|classic|podo}set colorsequence default selects a terminal-independent repeating sequence of eight colors. See set
linetype (p. 182), colors (p. 56).

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set colorsequence classic lets each separate terminal type provide its own sequence of line colors. The
number provided varies from 4 to more than 100, but most start with red/green/blue/magenta/cyan/yellow.
This was the default behaviour prior to version 5.
set colorsequence podo selects eight colors drawn from a set recommended by Wong (2011) [Nature
Methods 8:441] as being easily distinguished by color-blind viewers with either protanopia or deuteranopia.
In each case you can further customize the length of the sequence and the colors used. See set linetype(p. 182), colors (p. 56).

ClabelThis command has been deprecated. Use set cntrlabel instead. set clabel "format" is replaced by set
cntrlabel format "format". unset clabel is replaced by set cntrlabel onecolor.

Clip
Syntax:set clip {points|one|two|radial}
unset clip {points|one|two|radial}show clip

Default state:
unset clip points
set clip one
unset clip two
unset clip radial

Data points whose center lies inside the plot boundaries are normally drawn even if the finite size of thepoint symbol causes it to extend past a boundary line. set clip points causes such points to be clipped (i.e.
not drawn) even though the point center is inside the boundaries of a 2D plot. Data points whose centerlies outside the plot boundaries are never drawn.
unset clip causes a line segment in a plot not to be drawn if either end of that segment lies outside the plot
boundaries (i.e. xrange and yrange).
set clip one causes gnuplot to draw the in-range portion of line segments with one endpoint in range andone endpoint out of range. set clip two causes gnuplot to draw the in-range portion of line segments withboth endpoints out of range. Line segments that lie entirely outside the plot boundaries are never drawn.
set clip radial affects plotting only in polar mode. It clips lines against the radial bound established by
set rrange [0:MAX]. This criteria is applied in conjunction with set clip {one|two}. I.e. the portion ofa line between two points with R > RMAX that passes through the circle R = RMAX is drawn only if bothclip two and clip radial are set.
Notes:* set clip affects only points and lines produced by plot styles lines, linespoints, points, arrows, andvectors.
* Clipping of colored quadrangles drawn for pm3d surfaces and other solid objects is controlled set pm3d
clipping. The default is smooth clipping against the current zrange.
* Object clipping is controlled by the clip or noclip property of the individual object.
* In the current version of gnuplot, "plot with vectors" in polar mode does not test or clip against the
maximum radius.

Cntrlabel
Syntax:gnuplot 6.0

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set cntrlabel {format "format"} {font "font"}
set cntrlabel {start <int>} {interval <int>}
set cntrlabel onecolor

set cntrlabel controls the labeling of contours, either in the key (default) or on the plot itself in the caseof splot ... with labels. In the latter case labels are placed along each contour line according to thepointinterval or pointnumber property of the label descriptor. By default a label is placed on the 5thline segment making up the contour line and repeated every 20th segment. These defaults are equivalent to
set cntrlabel start 5 interval 20

They can be changed either via the set cntrlabel command or by specifying the interval in the splot
command itself
set contours; splot $FOO with labels point pointinterval -1

Setting the interval to a negative value means that the label appear only once per contour line. However if
set samples or set isosamples is large then many contour lines may be created, each with a single label.
A contour label is placed in the plot key for each linetype used. By default each contour level is given its own
linetype, so a separate label appears for each. The command set cntrlabel onecolor causes all contours
to be drawn using the same linetype, so only one label appears in the plot key. This command replaces anolder command unset clabel.

Cntrparam
set cntrparam controls the generation of contours and their smoothness for a contour plot. show contour
displays current settings of cntrparam as well as contour.
Syntax:set cntrparam { { linear| cubicspline| bspline| points <n>| order <n>| levels { <n>| auto {<n>}| discrete <z1> {,<z2>{,<z3>...}}| incremental <start>, <incr> {,<end>}}{{un}sorted}{firstlinetype N}}}
show contour

This command has two functions. First, it sets the values of z for which contours are to be determined. The
number of contour levels <n> should be an integral constant expression. <z1>, <z2> ... are real-valued
expressions. Second, it controls the appearance of the individual contour lines.
Keywords controlling the smoothness of contour lines:
linear, cubicspline, bspline — Controls type of approximation or interpolation. If linear, then straightline segments connect points of equal z magnitude. If cubicspline, then piecewise-linear contours areinterpolated between the same equal z points to form somewhat smoother contours, but which may undulate.
If bspline, a guaranteed-smoother curve is drawn, which only approximates the position of the points ofequal-z.
points — Eventually all drawings are done with piecewise-linear strokes. This number controls the numberof line segments used to approximate the bspline or cubicspline curve. Number of cubicspline or bspline
segments (strokes) = points * number of linear segments.
order — Order of the bspline approximation to be used. The bigger this order is, the smoother the resulting
contour. (Of course, higher order bspline curves will move further away from the original piecewise linear

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data.) This option is relevant for bspline mode only. Allowed values are integers in the range from 2 (linear)to 10.
Keywords controlling the selection of contour levels:
levels auto — This is the default. <n> specifies a nominal number of levels; the actual number will be
adjusted to give simple labels. If the surface is bounded by zmin and zmax, contours will be generated at
integer multiples of dz between zmin and zmax, where dz is 1, 2, or 5 times some power of ten (like the step
between two tic marks).
levels discrete — Contours will be generated at z = <z1>, <z2> ... as specified; the number of discretelevels sets the number of contour levels. In discrete mode, any set cntrparam levels <n> are ignored.
levels incremental — Contours are generated at values of z beginning at <start> and increasing by<increment>, until the number of contours is reached. <end> is used to determine the number of contour
levels, which will be changed by any subsequent set cntrparam levels <n>. If the z axis is logarithmic,<increment> will be interpreted as a multiplicative factor, as it is for set ztics, and <end> should not be
used.
Keywords controlling the assignment of linetype to contours:
By default the contours are generated in the reverse order specified (unsorted). Thus set cntrparamlevels increment 0, 10, 100 will create 11 contours levels starting with 100 and ending with 0. Adding
the keyword sorted re-orders the contours by increasing numerical value, which in this case would mean thefirst contour is drawn at 0.
By default contours are drawn using successive linetypes starting with the next linetype after that used forthe corresponding surface. Thus splot x*y lt 5 would use lt 6 for the first contour generated. If hidden3d
mode is active then each surface uses two linetypes. In this case using default settings would cause thefirst contour to use the same linetype as the hidden surface, which is undesirable. This can be avoided ineither of two ways. (1) Use set hidden3d offset N to change the linetype used for the hidden surface. A
good choice would be offset -1 since that will avoid all the contour linetypes. (2) Use the set cntrparamfirstlinetype N option to specify a block of linetypes used for contour lines independent of whatever wasused for the surface. This is particularly useful if you want to customize the set of contour linetypes. N <=0 restores the default.
If the command set cntrparam is given without any arguments specified all options are reset to the default:
set cntrparam order 4 points 5
set cntrparam levels auto 5 unsorted
set cntrparam firstlinetype 0

ExamplesExamples:set cntrparam bspline
set cntrparam points 7
set cntrparam order 10

To select levels automatically, 5 if the level increment criteria are met:
set cntrparam levels auto 5

To specify discrete levels at .1, .37, and .9:
set cntrparam levels discrete .1,1/exp(1),.9

To specify levels from 0 to 4 with increment 1:
set cntrparam levels incremental

0,1,4

To set the number of levels to 10 (changing an incremental end or possibly the number of auto levels):
set cntrparam levels 10

To set the start and increment while retaining the number of levels:

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set cntrparam levels incremental 100,50

To define and use a customized block of contour linetypes
set linetype 100 lc "red" dt '....'
do for [L=101:199] {if (L%10 == 0) {set linetype L lc "black" dt solid lw 2
} else {set linetype L lc "gray" dt solid lw 1}}
set cntrparam firstlinetype 100
set cntrparam sorted levels incremental 0, 1, 100

See also set contour (p. 160) for control of where the contours are drawn, and set cntrlabel (p. 156)
for control of the format of the contour labels and linetypes.
See also contours demo (contours.dem)
and contours with user defined levels demo (discrete.dem).

Color box
For plots that use palette coloring, in particular pm3d plots, the palette gradient is drawn in a color box
next to the plot unless it is switched off by unset colorbox.
set colorbox
set colorbox {{ vertical | horizontal } {{no}invert}{ default | bottom | user }{ origin x, y }{ size x, y }{ front | back }{ noborder | bdefault | border [line style] }}show colorbox
unset colorbox

The orientation of the color gradient is set by vertical or horizontal.
The color box position can be default or bottom or user. The bottom keyword is a convenience short
cut equivalent to
set colorbox horizontal user origin screen 0.1, 0.07 size 0.8, 0.03.

If the colorbox is placed underneath the plot, as it is with bottom, it may be useful to reserve additional
space for it: set bmargin screen 0.2.
origin x, y and size x, y are used to tailor the exact placement in user or bottom positioning. The x
and y values are interpreted as screen coordinates by default, and this is the only legal option for 3D plots.
2D plots, including splot with set view map, allow any coordinate system.
back/front control whether the color box is draw before or after the plot.
border turns the border on (this is the default). noborder turns the border off. If an positive integer
argument is given after border, it is used as a line style tag which is used for drawing the border, e.g.:
set style line 2604 linetype -1 linewidth .4
set colorbox border 2604

will use line style 2604, a thin line with the default border color (-1) for drawing the border. bdefault(which is the default) will use the default border line style for drawing the border of the color box.
The axis of the color box is called cb and it is controlled by means of the usual axes commands, i.e.
set/unset/show with cbrange, [m]cbtics, format cb, grid [m]cb, cblabel, and perhaps even cbdata,[no]cbdtics, [no]cbmtics.
set colorbox without any parameter switches the position to default. unset colorbox resets the default
parameters for the colorbox and switches the colorbox off.
See also help for set pm3d (p. 205), set palette (p. 198), and set style line (p. 218).

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Colornames
Gnuplot knows a limited number of color names. You
can use these to define the color range spanned by a
pm3d palette, to assign a named color to a particularlinetype or linestyle, or to define a gradient for the current color palette. Use the command show colornames
to list the known color names together with their RGB
component definitions. Examples:
set style line 1 linecolor "sea-green"
set palette defined (0 "dark-red", 1 "white")print sprintf("0x%06x", rgbcolor("dark-green"))0x006400

antiquewhiteaquamarine
beigebisqueblack
bluebrown4brown
chartreuse
coral
cyan
dark-blue
dark-chartreusedark-cyan
dark-goldenrod
dark-graydark-green
dark-khaki
dark-magenta
dark-olivegreen
dark-orange
dark-pinkdark-plumdark-reddark-salmon
dark-spring-green
dark-turquoise
dark-violet
dark-yellow
forest-green
goldenrod
gold
gray0 (grey0)
gray10 (grey10)
gray20 (grey20)
gray30 (grey30)
gray40 (grey40)
gray50 (grey50)
gray60 (grey60)
gray70 (grey70)
gray80 (grey80)
gray90 (grey90)
gray100 (grey100)
gray (grey)
green
greenyellow
honeydew
khaki1khaki
lemonchiffon
light-bluelight-coral
light-cyanlight-goldenrod
light-graylight-green
light-magenta
light-pinklight-red
light-salmon
light-turquoise
magentamedium-blue
mediumpurple3
midnight-blue
navy
olive
orangeorangered4
orange-red
orchid4
orchidpink
plum
purpleredroyalblue
salmonsandybrown
sea-green
seagreensienna1sienna4
skyblueslateblue
slategrayspring-green
steelbluetan1
turquoise
violetweb-blue
web-green
white
yellow4
yellow

Contour
set contour enables placement of contour lines on 3D surfaces. This option is available only for splot. It
requires grid data, e.g. a file in which all the points for a single y-isoline are listed, then all the points for the
next y-isoline, and so on. A single blank line (containing no characters other than blank spaces) separates
one y-isoline from the next. see grid data (p. 249) for more details.
If the data is not already gridded, set dgrid3d can be used to first create and populate an appropriate grid.
Syntax:set contour {base | surface | both}
unset contour
show contour

The three options specify where to draw the contours: base draws the contours on the grid base where thex/ytics are placed, surface draws the contours on the surfaces themselves, and both draws the contours on
both the base and the surface. If no option is provided, the default is base.
See also set cntrparam (p. 157) for the parameters that affect the drawing of contours, and set cntrlabel(p. 156) for control of labeling of the contours.
Note that this option places lines or labels without otherwise changing the appearance of the surface itself.
If you want to recolor the surface so that the areas bounded by contour lines are assigned distinct colors,use instead the contourfill plot style. See contourfill (p. 77).
While set contour is in effect, splot with <style> will place the style elements (points, lines, impulses,
labels, etc) along the contour lines. with pm3d will produce a pm3d surface and also contour lines. If you
want to mix other plot elements, say labels read from a file, with the contours generated while set contouris active you must append the keyword nocontours after that clause in the splot command.
The surface can be switched off (see unset surface (p. 222)) to give a contour-only graph. A 2D projectionof the contour lines and optional labels can be generated by
set view map
splot DATA with lines nosurface, DATA with labels

Older gnuplot versions used an alternative multi-step method to save the 3D contour lines into a file ordatablock and then plot them using a 2D plot command as shown below.
set contour
set table $datablock
splot DATA with lines nosurface
unset table# contour lines are now in $datablock, one contour per index
plot for [level=0:*] $datablock index level with lines

See also splot datafile (p. 246) and demos for contours (contours.dem)
and user defined contour levels (discrete.dem).

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Cornerpoles
By default splot draws a vertical line from each corner of a 3D surface to the base plane. These vertical lines
can be suppressed using unset cornerpoles.

Contourfill
The 3D plot style with contourfill slices a pm3d surface into sections delimited by a set of planes perpendicular to the z axis. The command set contourfill controls placement of these limiting planes and thecolors assigned to the individual sections.
Syntax:set contourfill auto N# split zrange evenly into N slices
set contourfill ztics# slice at each z axis major tickset contourfill cbtics# slice at each cb axis major tickset contourfill {palette | firstlinetype N}

The default is set contourfill auto 5 palette, which splits the current z range into five equal slices (6bounding planes) and assigns each slice the palette mapped color of its midpoint z value.
The options ztics or cbtics place split zrange by slicing at major ticks along that axis. For example to slice
specifically at z=2.5, z=7 and z=10 you could use the commands below.
set ztics add ("floor" 2.5, "boundary X" 7, "ceiling" 10)set contourfill ztics

If you do not want to use palette coloring for the sections, you can choose any arbitrary range of successive
linetypes and assign them the desired color sequence.
set for [i=101:110] linetype i lc mycolor[i]set contourfill firstlinetype 101

set contourfill palette restores palette coloring.

Dashtype
The set dashtype command allows you to define a dash pattern that can then be referred to by its index.
This is purely a convenience, as anywhere that would accept the dashtype by its numerical index would also
accept an explicit dash pattern. Example:
set dashtype 5 (2,4,2,6)
plot f1(x) dt 5plot f1(x) dt (2,4,2,6)
set linetype 5 dt 5
set dashtype 66 "..-"# define or redefine dashtype number 5# plot using the new dashtype# exactly the same plot as above# always use this dash pattern with linetype 5# define a new dashtype using a string

See also dashtype (p. 59).

Datafile
The set datafile command options control interpretation of fields read from input data files by the plot,
splot, and fit commands. Several options are currently implemented. The settings apply uniformly to alldata files read by subsequent commands; however see functionblocks (p. 114) for a way to work aroundthis if it is necessary to simultaneously handles files with conflicting formats.
Set datafile columnheaders
The set datafile columnheaders command guarantees that the first row of input will be interpreted ascolumn headers rather than as data values. It affects all input data sources to plot, splot, fit, and stats
commands. If this setting is disabled by unset datafile columnheaders, the same effect is triggered on a
per-file basis if there is an explicit columnheader() function in a using specifier or plot title associated withthat file. See also set key autotitle (p. 177) and columnheader (p. 142).

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Set datafile fortranThe set datafile fortran command enables a special check for values in the input file expressed as FortranD or Q constants. This extra check slows down the input process, and should only be selected if you do
in fact have datafiles containing Fortran D or Q constants. The option can be disabled again using unset
datafile fortran.
Set datafile nofpe trap
The set datafile nofpe trap command tells gnuplot not to re-initialize a floating point exception handler
before every expression evaluation used while reading data from an input file. This can significantly speed
data input from very large files at the risk of program termination if a floating-point exception is generated.
Set datafile missing
Syntax:set datafile missing "<string>"
set datafile missing NaN
show datafile missing
unset datafile

The set datafile missing command tells gnuplot there is a special string used in input data files to denotea missing data entry. There is no default character for missing. Gnuplot makes a distinction between
missing data and invalid data (e.g. "NaN", 1/0.). For example invalid data causes a gap in a line drawn
through sequential data points; missing data does not.
Non-numeric characters found in a numeric field will usually be interpreted as invalid rather than as a missing
data point unless they happen to match the missing string.
Conversely set datafile missing NaN causes all data or expressions evaluating to not-a-number (NaN) to
be treated as missing data. See the imageNaN demo.
The program notices a missing value flag in column N when the using specifier in a plot command directly
refers to the column as using N, using ($N), or using (function($N)). In these cases the expression,e.g. func($N), is not evaluated at all.
The current gnuplot version also notices direct references of the form (column(N)), and it notices during
evaluation if the expression depends even indirectly on a column value flagged "missing".
In all these cases the program treats the entire input data line as if it were not present at all. However if
an expression depends on a data value that is truly missing (e.g. an empty field in a csv file) it may not
be caught by these checks. If it evaluates to NaN it will be treated as invalid data rather than as a missing
data point. If you want to treat such invalid data the same as missing data, use the command set datafile
missing NaN.
Set datafile separator
The command set datafile separator tells gnuplot that data fields in subsequent input files are separated
by a specific character rather than by whitespace. The most common use is to read in csv (comma-separated
value) files written by spreadsheet or database programs. By default data fields are separated by whitespace.
Syntax:set datafile separator {whitespace | tab | comma | "<chars>"}

Examples:# Input file contains tab-separated fields
set datafile separator "\t"# Input file contains comma-separated values fields
set datafile separator comma# Input file contains fields separated by either * or |set datafile separator "*|"

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Set datafile commentschars
The command set datafile commentschars specifies what characters can be used in a data file to begin
comment lines. If the first non-blank character on a line is one of these characters then the rest of the dataline is ignored. Default value of the string is "#!" on VMS and "#" otherwise.
Syntax:set datafile commentschars {"<string>"}show datafile commentschars
unset commentschars

Then, the following line in a data file is completely ignored# 1 2 3 4

but the following
1 # 3 4will be interpreted as garbage in the 2nd column followed by valid data in the 3rd and 4th columns.
Example:set datafile commentschars "#!%"

Set datafile binary
The set datafile binary command is used to set the defaults when reading binary data files. The syntax
matches precisely that used for commands plot and splot. See binary matrix (p. 246) and binary
general (p. 121) for details about the keywords that can be present in <binary list>.
Syntax:set datafile binary <binary list>
show datafile binary
show datafile
unset datafile

Examples:set datafile binary filetype=auto
set datafile binary array=(512,512) format="%uchar"show datafile binary# list current settings

Decimalsign
The set decimalsign command selects a decimal sign for numbers printed into tic labels or set label
strings.
Syntax:set decimalsign {<value> | locale {"<locale>"}}unset decimalsign
show decimalsign

The argument <value> is a string to be used in place of the usual decimal point. Typical choices include
the period, ’.’, and the comma, ’,’, but others may be useful, too. If you omit the <value> argument, thedecimal separator is not modified from the usual default, which is a period. Unsetting decimalsign has thesame effect as omitting <value>.
Example:Correct typesetting in most European countries requires:set decimalsign ','164

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Please note: If you set an explicit string, this affects only numbers that are printed using gnuplot’s gprintf()
formatting routine, including axis tics. It does not affect the format expected for input data, and it does
not affect numbers printed with the sprintf() formatting routine. To change the behavior of both input andoutput formatting, instead use the form
set decimalsign locale

This instructs the program to use both input and output formats in accordance with the current setting of
the LC ALL, LC NUMERIC, or LANG environmental variables.
set decimalsign locale "foo"This instructs the program to format all input and output in accordance with locale "foo", which must
be installed. If locale "foo" is not found then an error message is printed and the decimal sign setting is
unchanged. On linux systems you can get a list of the locales installed on your machine by typing "locale-a". A typical linux locale string is of the form "sl SI.UTF-8". A typical Windows locale string is of theform "Slovenian Slovenia.1250" or "slovenian". Please note that interpretation of the locale settings is doneby the C library at runtime. Older C libraries may offer only partial support for locale settings such as thethousands grouping separator character.
set decimalsign locale; set decimalsign "."This sets all input and output to use whatever decimal sign is correct for the current locale, but over-rides
this with an explicit ’.’ in numbers formatted using gnuplot’s internal gprintf() function.

Dgrid3d
The set dgrid3d command enables and sets parameters for mapping non-grid data onto a grid. See splot
grid data (p. 249) for details about the grid data structure. Aside from its use in fitting 3D surfaces, thisprocess can also be used to generate 2D heatmaps, where the ’z’ value of each point contributes to a local
weighted value.
Syntax:set dgrid3d {<rows>} {,{<cols>}} splines
set dgrid3d {<rows>} {,{<cols>}} qnorm {<norm>}
set dgrid3d {<rows>} {,{<cols>}} {gauss | cauchy | exp | box | hann}{kdensity} {<dx>} {,<dy>}unset dgrid3d
show dgrid3d

By default dgrid3d is disabled. When enabled, 3D data points read from a file are treated as a scattereddata set used to fit a gridded surface. The grid dimensions are derived from the bounding box of the scattereddata subdivided by the row/col size parameters from the set dgrid3d statement. The grid is equally spaced
in x (rows) and in y (columns); the z values are computed as weighted averages or spline interpolationsof the scattered points’ z values. In other words, a regularly spaced grid is created and then a smoothapproximation to the raw data is evaluated for each grid point. This surface is then plotted in place of theraw data.
While dgrid3d mode is enabled, if you want to plot individual points or lines without using them to createa gridded surface you must append the keyword nogrid to the corresponding splot command.
The number of columns defaults to the number of rows, which defaults to 10.
Several algorithms are available to calculate the approximation from the raw data. Some of these algorithms
can take additional parameters. These interpolations are such that the closer the data point is to a grid
point, the more effect it has on that grid point.
The splines algorithm calculates an interpolation based on thin plate splines. It does not take additionalparameters.
The qnorm algorithm calculates a weighted average of the input data at each grid point. Each data point
is weighted by the inverse of its distance from the grid point raised to some power. The power is specified
as an optional integer parameter that defaults to 1. This algorithm is the default.

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Finally, several smoothing kernels are available to calculate weighted averages: z = Sum i w(d i) * z i /Sum i w(d i), where z i is the value of the i-th data point and d i is the distance between the current grid
point and the location of the i-th data point. All kernels assign higher weights to data points that are close
to the current grid point and lower weights to data points further away.
The following kernels are available:
gauss :
cauchy :
exp :
box :
hann :

w(d) = exp(-d*d)w(d) = 1/(1 + d*d)w(d) = exp(-d)w(d) = 1= 0w(d) = 0.5*(1+cos(pi*d))w(d) = 0

if d<1otherwise
if d<1otherwise

When using one of these five smoothing kernels, up to two additional numerical parameters can be specified:dx and dy. These are used to rescale the coordinate differences when calculating the distance: d i = sqrt(((x-x i)/dx)**2 + ((y-y i)/dy)**2 ), where x,y are the coordinates of the current grid point and x i,y i are
the coordinates of the i-th data point. The value of dy defaults to the value of dx, which defaults to 1. The
parameters dx and dy make it possible to control the radius over which data points contribute to a grid
point IN THE UNITS OF THE DATA ITSELF.
The optional keyword kdensity, which must come after the name of the kernel, but before the optional scaleparameters, modifies the algorithm so that the values calculated for the grid points are not divided by thesum of the weights ( z = Sum i w(d i) * z i ). If all z i are constant, this effectively plots a bivariate kernel
density estimate: a kernel function (one of the five defined above) is placed at each data point, the sum ofthese kernels is evaluated at every grid point, and this smooth surface is plotted instead of the original data.
This is similar in principle to what the smooth kdensity option does to 1D datasets. See kdensity2d.dem
and heatmap points.dem for usage example.
The dgrid3d option is a simple scheme which replaces
scattered data with weighted averages on a regular grid.
More sophisticated approaches to this problem exist andshould be used to preprocess the data outside gnuplot
if this simple solution is found inadequate.
See also the online demos for dgrid3d
scatterand heatmap points

12
10
8
6
4
2
0
-20
0.5

Smooth surface fit to scattered points
set dgrid3d 30,30 splines

1
1.5

2
2.5

3 0

0.5

1

1.5

2

Dummy
The set dummy (p. 165) command changes the default dummy variable names.
Syntax:set dummy {<dummy-var>} {,<dummy-var>}show dummy

By default, gnuplot assumes that the independent, or "dummy", variable for the plot command is "t" if
in parametric or polar mode, or "x" otherwise. Similarly the independent variables for the splot commandare "u" and "v" in parametric mode (splot cannot be used in polar mode), or "x" and "y" otherwise.
It may be more convenient to call a dummy variable by a more physically meaningful or conventional name.
For example, when plotting time functions:set dummy t
plot sin(t), cos(t)Examples:set dummy u,v
set dummy ,s166

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The second example sets the second variable to s. To reset the dummy variable names to their default values,
use
unset dummy

Encoding
The set encoding command selects a character encoding.
Syntax:set encoding {<value>}set encoding locale
show encoding

Valid values aredefault
iso_8859_1- tells a terminal to use its default encoding- the most common Western European encoding prior to UTF-8.
Known in the PostScript world as 'ISO-Latin1'.
iso_8859_15 - a variant of iso_8859_1 that includes the Euro symbol
iso_8859_2 - used in Central and Eastern Europe
iso_8859_9 - used in Turkey (also known as Latin5)
koi8r- popular Unix cyrillic encoding
koi8u- Ukrainian Unix cyrillic encoding
cp437- codepage for MS-DOS
cp850- codepage for OS/2, Western Europe
cp852- codepage for OS/2, Central and Eastern Europe
cp950- MS version of Big5 (emf terminal only)
cp1250- codepage for MS Windows, Central and Eastern Europe
cp1251- codepage for 8-bit Russian, Serbian, Bulgarian, Macedonian
cp1252- codepage for MS Windows, Western Europe
cp1254- codepage for MS Windows, Turkish (superset of Latin5)sjis- shift-JIS Japanese encoding
utf8- variable-length (multibyte) representation of Unicode
entry point for each character

The command set encoding locale is different from the other options. It attempts to determine the current
locale from the runtime environment. On most systems this is controlled by the environmental variables
LC ALL, LC CTYPE, or LANG. This mechanism is necessary, for example, to pass multibyte character
encodings such as UTF-8 or EUC JP to the wxt and pdf terminals. This command does not affect the
locale-specific representation of dates or numbers. See also set locale (p. 184) and set decimalsign(p. 163).
Generally you should set the encoding before setting the terminal type, as it may affect the selection of fonts.

Errorbars
The set errorbars command controls the tics at the ends of error bars, and also at the end of the whiskers
belonging to a boxplot.
Syntax:set errorbars {small | large | fullwidth | <size>} {front | back}{line-properties}
unset errorbars
show errorbars

small is a synonym for 0.0 (no crossbar), and large for 1.0. The default is 1.0 if no size is given.
The keyword fullwidth is relevant only to boxplots and to histograms with errorbars. It sets the width ofthe errorbar ends to be the same as the width of the associated box. It does not change the width of thebox itself.
The front and back keywords are relevant only to errorbars attached to filled rectangles (boxes, candlesticks,
histograms).
Error bars are by default drawn using the same line properties as the border of the associated box. You canchange this by providing a separate set of line properties for the error bars.

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set errorbars linecolor black linewidth 0.5 dashtype '.'Fit
The set fit command controls the options for the fit command.
Syntax:set fit {nolog | logfile {"<filename>"|default}}{{no}quiet|results|brief|verbose}{{no}errorvariables}{{no}covariancevariables}{{no}errorscaling}{{no}prescale}{maxiter <value>|default}{limit <epsilon>|default}{limit_abs <epsilon_abs>}{start-lambda <value>|default}{lambda-factor <value>|default}{script {"<command>"|default}}{v4 | v5}
unset fitshow fit

The logfile option defines where the fit command writes its output. The <filename> argument must be
enclosed in single or double quotes. If no filename is given or unset fit is used the log file is reset to its
default value "fit.log" or the value of the environmental variable FIT LOG. If the given logfile name ends
with a / or \, it is interpreted to be a directory name, and the actual filename will be "fit.log" in that
directory.
By default the information written to the log file is also echoed to the terminal session. set fit quiet turns
off the echo, whereas results prints only final results. brief gives one line summaries for every iteration of
the fit in addition. verbose yields detailed iteration reports as in version 4.
If the errorvariables option is turned on, the error of each fitted parameter computed by fit will be copied
to a user-defined variable whose name is formed by appending " err" to the name of the parameter itself.
This is useful mainly to put the parameter and its error onto a plot of the data and the fitted function, forreference, as in:set fit errorvariables
fit f(x) 'datafile' using 1:2 via a, b
print "error of a is:", a_err
set label 1 sprintf("a=%6.2f +/- %6.2f", a, a_err)
plot 'datafile' using 1:2, f(x)If the errorscaling option is specified, which is the default, the calculated parameter errors are scaledwith the reduced chi square. This is equivalent to providing data errors equal to the calculated standard
deviation of the fit (FIT STDFIT) resulting in a reduced chi square of one. With the noerrorscaling option
the estimated errors are the unscaled standard deviations of the fit parameters. If no weights are specified
for the data, parameter errors are always scaled.
If the prescale option is turned on, parameters are prescaled by their initial values before being passed to
the Marquardt-Levenberg routine. This helps tremendously if there are parameters that differ in size by
many orders of magnitude. Fit parameters with an initial value of exactly zero are never prescaled.
The maximum number of iterations may be limited with the maxiter option. A value of 0 or default meansthat there is no limit.
The limit option can be used to change the default epsilon limit (1e-5) to detect convergence. When thesum of squared residuals changes by a factor less than this number (epsilon), the fit is considered to have’converged’. The limit abs option imposes an additional absolute limit in the change of the sum of squared
residuals and defaults to zero.
If you need even more control about the algorithm, and know the Marquardt-Levenberg algorithm well,
the following options can be used to influence it. The startup value of lambda is normally calculated

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automatically from the ML-matrix, but if you want to, you may provide your own using the start lambda
option. Setting it to default will re-enable the automatic selection. The option lambda factor sets thefactor by which lambda is increased or decreased whenever the chi-squared target function increased or
decreased significantly. Setting it to default re-enables the default factor of 10.0.
The script option may be used to specify a gnuplot command to be executed when a fit is interrupted— see fit (p. 105). This setting takes precedence over the default of replot and the environment variable
FIT SCRIPT.
If the covariancevariables option is turned on, the covariances between final parameters will be saved
to user-defined variables. The variable name for a certain parameter combination is formed by prepending"FIT COV " to the name of the first parameter and combining the two parameter names by " ". For
example given the parameters "a" and "b" the covariance variable is named "FIT COV a b".
In version 5 the syntax of the fit command changed and it now defaults to unitweights if no ’error’ keyword
is given. The v4 option restores the default behavior of gnuplot version 4, see also fit (p. 105).

Fontpath
Syntax:set fontpath "/directory/where/my/fonts/live"
set term postscript fontfile <filename>[DEPRECATED in version 5.4]
The fontpath directory is relevant only for embedding fonts in postscript output produced by the postscript
terminal. It has no effect on other gnuplot terminals. If you are not embedding fonts you do not need thiscommand, and even if you are embedding fonts you only need it for fonts that cannot be found via the otherpaths below.
Earlier versions of gnuplot tried to emulate a font manager by tracking multiple directory trees containing
fonts. This is now replaced by a search in the following places: (1) an absolute path given in the set
term postscript fontfile command (2) the current directory (3) any of the directories specified by set
loadpath (4) the directory specified by set fontpath (5) the directory provided in environmental variable
GNUPLOT FONTPATH
Note: The search path for fonts specified by filename for the libgd terminals (png gif jpeg sixel) is controlled
by environmental variable GDFONTPATH.

Format
The format of the tic-mark labels can be set with the set format command or with the set tics format orindividual set {axis}tics format commands. For information on using an explicit format for input data
see using format (p. 136).
Syntax:set format {<axes>} {"<format-string>"} {numeric|timedate|geographic}
show format

where <axes> is either x, y, xy, x2, y2, z, cb or nothing (which applies the format to all axes). The
following two commands are equivalent:set format y "%.2f"
set ytics format "%.2f"

The length of the string is restricted to 100 characters. The default format is "% h", "$%h$" for LaTeX
terminals. Other formats such as "%.2f" or "%3.0em" are often desirable. "set format" with no following
string will restore the default.
If the empty string "" is given, tics will have no labels, although the tic mark will still be plotted. To
eliminate the tic marks, use unset xtics or set tics scale 0.

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169

Newline (\n) and enhanced text markup is accepted in the format string. Use double-quotes rather thansingle-quotes in this case. See also syntax (p. 67). Characters not preceded by "%" are printed verbatim.
Thus you can include spaces and labels in your format string, such as "%g m", which will put " m" after
each number. If you want "%" itself, double it: "%g %%".
See also set xtics (p. 235) for more information about tic labels, and set decimalsign (p. 163) for how to
use non-default decimal separators in numbers printed this way. See also electron demo (electron.dem).

Gprintf
The string function gprintf("format",x) uses gnuplot’s own format specifiers, as do the gnuplot commands
set format, set timestamp, and others. These format specifiers are not the same as those used by thestandard C-language routine sprintf(). gprintf() accepts only a single variable to be formatted. Gnuplot
also provides an sprintf("format",x1,x2,...) routine if you prefer. For a list of gnuplot’s format options, seeformat specifiers (p. 169).
Format specifiers
The acceptable formats (if not in time/date mode) are:Format%f%e or %E
%g or %G
%h or %H
%x or %X
%o or %O
%t
%l
%s
%T
%L
%S
%c
%b
%B
%P

Tic-mark label numerical format specifiers
Explanation
floating point notation
exponential notation; an ”e” or ”E” before the power
the shorter of %e (or %E) and %flike %g with "x10^{%S}" or "*10^{%S}" instead of "e%S"
hex
octal
mantissa to base 10
mantissa to base of current logscalemantissa to base of current logscale; scientific power
power to base 10
power to base of current logscalescientific power
character replacement for scientific power
mantissa of ISO/IEC 80000 notation (ki, Mi, Gi, Ti, Pi, Ei, Zi, Yi)
prefix of ISO/IEC 80000 notation (ki, Mi, Gi, Ti, Pi, Ei, Zi, Yi)
multiple of pi

A ’scientific’ power is one such that the exponent is a multiple of three. Character replacement of scientificpowers ("%c") has been implemented for powers in the range -18 to +18. For numbers outside of this range
the format reverts to exponential.
Other acceptable modifiers (which come after the "%" but before the format specifier) are "-", which leftjustifies the number; "+", which forces all numbers to be explicitly signed; " " (a space), which makes
positive numbers have a space in front of them where negative numbers have "-"; "#", which places adecimal point after floats that have only zeroes following the decimal point; a positive integer, which defines
the field width; "0" (the digit, not the letter) immediately preceding the field width, which indicates thatleading zeroes are to be used instead of leading blanks; and a decimal point followed by a non-negative
integer, which defines the precision (the minimum number of digits of an integer, or the number of digits
following the decimal point of a float).
Some systems may not support all of these modifiers but may also support others; in case of doubt, checkthe appropriate documentation and then experiment.

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Examples:set format y "%t"; set ytics (5,10)# "5.0" and "1.0"
set format y "%s"; set ytics (500,1000)# "500" and "1.0"
set format y "%+-12.3f"; set ytics(12345)# "+12345.000 "set format y "%.2t*10^%+03T"; set ytic(12345)# "1.23*10^+04"
set format y "%s*10^{%S}"; set ytic(12345)# "12.345*10^{3}"
set format y "%s %cg"; set ytic(12345)# "12.345 kg"
set format y "%.0P pi"; set ytic(6.283185)# "2 pi"set format y "%.0f%%"; set ytic(50)# "50%"
set log y 2; set format y '%l'; set ytics (1,2,3)#displays "1.0", "1.0" and "1.5" (since 3 is 1.5 * 2^1)

There are some problem cases that arise when numbers like 9.999 are printed with a format that requires
both rounding and a power.
If the data type for the axis is time/date, the format string must contain valid codes for the ’strftime’function (outside of gnuplot, type "man strftime"). See set timefmt (p. 225) for a list of the allowed
input format codes.
Time/date specifiers
There are two groups of time format specifiers: time/date and relative time. These may be used to generate
axis tic labels or to encode time in a string. See set xtics time (p. 238), strftime (p. 41), strptime(p. 41).
The time/date formats are
Date Specifiers
Format%a%A%b or %h
%B
%d
%D
%F
%k
%H
%l
%I
%j
%m
%M
%p
%r
%R
%S
%s
%T
%U
%w
%W
%y
%Y
%z
%Z

Explanationabbreviated name of day of the week
full name of day of the week
abbreviated name of the monthfull name of the monthday of the month, 01–31
shorthand for "%m/%d/%y" (only output)
shorthand for "%Y-%m-%d" (only output)
hour, 0–23 (one or two digits)hour, 00–23 (always two digits)hour, 1–12 (one or two digits)hour, 01–12 (always two digits)
day of the year, 001–366
month, 01–12
minute, 00–60”am” or ”pm”
shorthand for "%I:%M:%S %p" (only output)
shorthand for %H:%M" (only output)
second, integer 00–60 on output, (double) on input
number of seconds since start of year 1970
shorthand for "%H:%M:%S" (only output)
week of the year (CDC/MMWR ”epi week”) (ignored on input)
day of the week, 0–6 (Sunday = 0)week of the year (ISO 8601 week date) (ignored on input)
year, 0-99 in range 1969-2068
year, 4-digit
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171

For more information on the %W format (ISO week of year) see tm week (p. 46). The %U format(CDC/MMWR epidemiological week) is similar to %W except that it uses weeks that start on Sunday
rather than Monday. Caveat: Both the %W and the %U formats were unreliable in gnuplot versions prior
to 5.4.2. See unit test "week date.dem".
The relative time formats express the length of a time interval on either side of a zero time point. The
relative time formats are
Time Specifiers
Format
%tD
%tH
%tM
%tS

Explanation+/- days relative to time=0+/- hours relative to time=0 (does not wrap at 24)+/- minutes relative to time=0+/- seconds associated with previous tH or tM field

Numerical formats may be preceded by a "0" ("zero") to pad the field with leading zeroes, and preceded bya positive digit to define the minimum field width. The %S, and %t formats also accept a precision specifier
so that fractional hours/minutes/seconds can be written.
ExamplesExamples of date format:

Suppose the x value in seconds corresponds a time slightly before midnight on 25 Dec 1976. The text printed
for a tic label at this position would be
set format x
set format x "%A, %d %b %Y"
set format x "%r %D"
set xtics time format "%B"

# defaults to "12/25/76 \n 23:11"# "Saturday, 25 Dec 1976"# "11:11:11 pm 12/25/76"# "December"

Examples of time format:
The date format specifiers encode a time in seconds as a clock time on a particular day. So hours run only
from 0-23, minutes from 0-59, and negative values correspond to dates prior to the epoch (1-Jan-1970). In
order to report a time value in seconds as some number of hours/minutes/seconds relative to a time 0, usetime formats %tH %tM %tS. To report a value of -3672.50 seconds
set format x
set format x "%tH:%tM:%tS"
set format x "%.2tH hours"
set format x "%tM:%.2tS"# default date format "12/31/69 \n 22:58"# "-01:01:12"# "-1.02 hours"# "-61:12.50"

Grid
The set grid command allows grid lines to be drawn on the plot.
Syntax:set grid {{no}{m}xtics} {{no}{m}ytics} {{no}{m}ztics}{{no}{m}x2tics} {{no}{m}y2tics} {{no}{m}rtics}{{no}{m}cbtics}{polar {<angle>}}{layerdefault | front | back}{{no}vertical}{<line-properties-major> {, <line-properties-minor>}}unset gridshow grid

The grid can be enabled and disabled for the major and/or minor tic marks on any axis, and the linetypeand linewidth can be specified for major and minor grid lines, also via a predefined linestyle, as far as theactive terminal driver supports this (see set style line (p. 218)).

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A polar grid can be drawn for 2D plots. This is the default action of set grid if the program is already inpolar mode, but can be enabled explicitly by set grid polar <angle> rtics whether or not the program isin polar mode. Circles are drawn to intersect major and/or minor tics along the r axis, and radial lines are
drawn with a spacing of <angle>. Tic marks around the perimeter are controlled by set ttics, but these
do not produce radial grid lines.
The pertinent tics must be enabled before set grid can draw them; gnuplot will quietly ignore instructions
to draw grid lines at non-existent tics, but they will appear if the tics are subsequently enabled.
If no linetype is specified for the minor gridlines, the same linetype as the major gridlines is used. The
default polar angle is 30 degrees.
If front is given, the grid is drawn on top of the graphed data. If back is given, the grid is drawn underneaththe graphed data. Using front will prevent the grid from being obscured by dense data. The default setup,
layerdefault, is equivalent to back for 2D plots. In 3D plots the default is to split up the grid and thegraph box into two layers: one behind, the other in front of the plotted data and functions. Since hidden3d
mode does its own sorting, it ignores all grid drawing order options and passes the grid lines through thehidden line removal machinery instead. These options actually affect not only the grid, but also the lines
output by set border and the various ticmarks (see set xtics (p. 235)).
In 3D plots grid lines at x- and y- axis tic positions are by default drawn only on the base plane parallel toz=0. The vertical keyword activates drawing grid lines in the xz and yz planes also, running from zmin tozmax.
Z grid lines are drawn on the bottom of the plot. This looks better if a partial box is drawn around the plot
— see set border (p. 153).

Hidden3d
The set hidden3d command enables hidden line removal for surface plotting (see splot (p. 245)). Some
optional features of the underlying algorithm can also be controlled using this command.
Syntax:set hidden3d {defaults} |{ {front|back}{{offset <offset>} | {nooffset}}{trianglepattern <bitpattern>}{{undefined <level>} | {noundefined}}{{no}altdiagonal}{{no}bentover} }unset hidden3dshow hidden3d

In contrast to the usual display in gnuplot, hidden line removal actually treats the given function or data
grids as real surfaces that can’t be seen through, so plot elements behind the surface will be hidden by it.
For this to work, the surface needs to have ’grid structure’ (see splot datafile (p. 246) about this), and it
has to be drawn with lines or with linespoints.
When hidden3d is set, both the hidden portion of the surface and possibly its contours drawn on the base(see set contour (p. 160)) as well as the grid will be hidden. Each surface has its hidden parts removed
with respect to itself and to other surfaces, if more than one surface is plotted. Contours drawn on thesurface (set contour surface) don’t work.
hidden3d also affects 3D plotting styles points, labels, vectors, and impulses even if no surface ispresent in the graph. Unobscured portions of each vector are drawn as line segments (no arrowheads).
Individual plots within the graph may be explicitly excluded from this processing by appending the extra
option nohidden3d to the with specifier.
Hidden3d does not affect solid surfaces drawn using the pm3d mode. To achieve a similar effect purely
for pm3d surfaces, use instead set pm3d depthorder. To mix pm3d surfaces with normal hidden3d
processing, use the option set hidden3d front to force all elements included in hidden3d processing to be
drawn after any remaining plot elements, including the pm3d surface.

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Functions are evaluated at isoline intersections. The algorithm interpolates linearly between function points
or data points when determining the visible line segments. This means that the appearance of a function
may be different when plotted with hidden3d than when plotted with nohidden3d because in the lattercase functions are evaluated at each sample. Please see set samples (p. 213) and set isosamples (p. 174)
for discussion of the difference.
The algorithm used to remove the hidden parts of the surfaces has some additional features controllable bythis command. Specifying defaults will set them all to their default settings, as detailed below. If defaults
is not given, only explicitly specified options will be influenced: all others will keep their previous values, so
you can turn on/off hidden line removal via set {no}hidden3d, without modifying the set of options you
chose.
The first option, offset, influences the linetype used for lines on the ’back’ side. Normally, they are drawn
in a linetype one index number higher than the one used for the front, to make the two sides of the surface
distinguishable. You can specify a different linetype offset to add instead of the default 1, by offset <offset>.
Option nooffset stands for offset 0, making the two sides of the surface use the same linetype.
Next comes the option trianglepattern <bitpattern>. <bitpattern> must be a number between 0 and
7, interpreted as a bit pattern. Each bit determines the visibility of one edge of the triangles each surface
is split up into. Bit 0 is for the ’horizontal’ edges of the grid, Bit 1 for the ’vertical’ ones, and Bit 2 forthe diagonals that split each cell of the original grid into two triangles. The default pattern is 3, making all
horizontal and vertical lines visible, but not the diagonals. You may want to choose 7 to see those diagonals
as well.
The undefined <level> option lets you decide what the algorithm is to do with data points that are
undefined (missing data, or undefined function values), or exceed the given x-, y- or z-ranges. Such points
can either be plotted nevertheless, or taken out of the input data set. All surface elements touching a pointthat is taken out will be taken out as well, thus creating a hole in the surface. If <level> = 3, equivalent to
option noundefined, no points will be thrown away at all. This may produce all kinds of problems elsewhere,
so you should avoid this. <level> = 2 will throw away undefined points, but keep the out-of-range ones.
<level> = 1, the default, will get rid of out-of-range points as well.
By specifying noaltdiagonal, you can override the default handling of a special case can occur if undefinedis active (i.e. <level> is not 3). Each cell of the grid-structured input surface will be divided in two triangles
along one of its diagonals. Normally, all these diagonals have the same orientation relative to the grid. If
exactly one of the four cell corners is excluded by the undefined handler, and this is on the usual diagonal,
both triangles will be excluded. However if the default setting of altdiagonal is active, the other diagonal
will be chosen for this cell instead, minimizing the size of the hole in the surface.
The bentover option controls what happens to another special case, this time in conjunction with thetrianglepattern. For rather crumply surfaces, it can happen that the two triangles a surface cell is divided
into are seen from opposite sides (i.e. the original quadrangle is ’bent over’), as illustrated in the following
ASCII art:
original quadrangle:("set view 0,0")

A--B
| /|
|/ |
C--D

displayed quadrangle:("set view 75,75" perhaps)C----B
|\
|
| \ |
| \ |
|
\|
A
D

If the diagonal edges of the surface cells aren’t generally made visible by bit 2 of the <bitpattern> there,
the edge CB above wouldn’t be drawn at all, normally, making the resulting display hard to understand.
Therefore, the default option of bentover will turn it visible in this case. If you don’t want that, you may
choose nobentover instead. See also hidden line removal demo (hidden.dem)
and complex hidden line demo (singulr.dem).

History
Syntax:

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set history {size <N>} {quiet|numbers} {full|trim} {default}

A log of recent gnuplot commands is kept by default in $HOME/.gnuplot history. If this file is not foundand xdg desktop support is enabled, the program will instead use $XDG STATE HOME/gnuplot history.
When leaving gnuplot the value of history size limits the number of lines saved to the history file. set
history size -1 allows an unlimited number of lines to be written to the history file.
By default the history command prints a line number in front of each command. history quiet suppresses
the number for this command only. set history quiet suppresses numbers for all future history commands.
The trim option reduces the number of duplicate lines in the history list by removing earlier instances of
the current command.
Default settings: set history size 500 numbers trim.

Isosamples
The isoline density (grid) for plotting functions as surfaces may be changed by the set isosamples command.
Syntax:set isosamples <iso_1> {,<iso_2>}
show isosamples

Each function surface plot will have <iso 1> iso-u lines and <iso 2> iso-v lines. If you only specify <iso 1>,<iso 2> will be set to the same value as <iso 1>. By default, sampling is set to 10 isolines per u or v axis.
A higher sampling rate will produce more accurate plots, but will take longer. These parameters have noeffect on data file plotting.
An isoline is a curve parameterized by one of the surface parameters while the other surface parameter isfixed. Isolines provide a simple means to display a surface. By fixing the u parameter of surface s(u,v), theiso-u lines of the form c(v) = s(u0,v) are produced, and by fixing the v parameter, the iso-v lines of the formc(u) = s(u,v0) are produced.
When a function surface plot is being done without the removal of hidden lines, set samples controls thenumber of points sampled along each isoline; see set samples (p. 213) and set hidden3d (p. 172). The
contour algorithm assumes that a function sample occurs at each isoline intersection, so change in samples
as well as isosamples may be desired when changing the resolution of a function surface/contour.

Isosurface
Syntax:set isosurface {mixed|triangles}
set isosurface {no}insidecolor <n>Surfaces plotted by the command splot $voxelgrid with isosurface are by default constructed from a
mixture of quadrangles and triangles. The use of quadrangles creates a less complicated visual impression.
This command provides an option to tessellate with only triangles.
By default the inside of an isosurface is drawn in a separate color. The method of choosing that color is thesame as for hidden3d surfaces, where an offset <n> is added to the base linetype. To draw both the insideand outside surfaces in the same color, use set isosurface noinsidecolor.

Isotropic
Syntax:set isotropic
unset isotropic

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set isotropic adjusts the aspect ratio and size of the plot so that the unit length along the x, y, and z
axes is the same. It is equivalent to set size ratio -1; set view equal xyz and supersedes both of thosecommands. This affects both 2D and 3D plots.
unset isotropic relaxes both the 2D and 3D constraints. It is equivalent to the older commands set size
noratio; set view noequal axes but hopefully easier to remember.

JitterSyntax:set jitter {overlap <yposition>} {spread <factor>} {wrap <limit>}{swarm|square|vertical}

Examples:set jitter# jitter points within 1 character width
set jitter overlap 1.5# jitter points within 1.5 character width
set jitter over 1.5 spread 0.5 # same but half the displacement on x

When one or both coordinates of a data set are restricted to discrete values then many points may lie exactly
on top of each other. Jittering introduces an offset to the coordinates of these superimposed points thatspreads them into a cluster. The threshold value for treating the points as being overlapped may be specified
in character widths or any of the usual coordinate options. See coordinates (p. 33). Jitter affects 2D plot
styles with points and with impulses. It also affects 3D plotting of voxel grids.
The default jittering operation displaces points only along x. This produces a distinctive pattern sometimes
called a "bee swarm plot". The optional keyword square adjusts the y coordinate of displaced points inaddition to their x coordinate so that the points lie in distinct layers separated by at least the overlap
distance.
To jitter along y (only) rather than along x, use keyword vertical.
The maximum displacement (in character units) can be limited using the wrap keyword.
Note that both the overlap criterion and the magnitude of jitter default to one character unit. Thus theplot appearance will change with the terminal font size, canvas size, or zoom factor. To avoid this you canspecify the overlap criterion in the y axis coordinate system (the first keyword) and adjust the point sizeand spread multiplier as appropriate. See coordinates (p. 33), pointsize (p. 210).
Caveat: jitter is incompatible with "pointsize variable".
set jitter is also useful in 3D plots of voxel data. Because voxel grids are regular lattices of evenly spaced
points, many view angles cause points to overlap and/or generate Moiré patterns. These artifacts can beremoved by displacing the symbol drawn at each grid point by a random amount.

Key
The set key command enables a key (or legend) containing a title and a sample (line, point, box) for eachplot in the graph. The key may be turned off by requesting set key off or unset key. Individual key
entries may be turned off by using the notitle keyword in the corresponding plot command. The text of thetitles is controlled by the set key autotitle option or by the title keyword of individual plot and splot
commands.
See key placement (p. 178) for syntax of options that affect where the key is placed.
See key layout (p. 177) for syntax of options that affect the content of the key.
Syntax (global options):
set key {on|off} {default}{font "<face>,<size>"} {{no}enhanced}{{no}title "<text>" {<font or other text options>}}{{no}autotitle {columnheader}}176

gnuplot 6.0{{no}box {<line properties>}} {{no}opaque {fc <colorspec>}}{width <width_increment>} {height <height_increment>}
unset key

By default the key is placed in the upper right inside corner of the graph. The optional font becomes thedefault for all elements of the key. You can provide an option title for the key as a whole that spans thefull width of the key at the top. This title can use different font, color, justification, and enhancement fromindividual plot titles.
Each component in a plot command is represented in the key by a single line containing corresponding title
text and a line or symbol or shape representing the plot style. The title text may be auto-generated or
given explicitly in the plot command as title "text". Using the keyword notitle in the plot command
will suppress generation of the entire line. If you want to suppress the text only, use title "" in the plot
command.
Contour plots generated additional entries in the key (see cntrlabel (p. 156)). You can add extra lines to
the key by inserting a dummy plot command that uses the keyword keyentry rather than a filename or afunction. See keyentry (p. 177).
A box can be drawn around the key (box {...}) with user-specified line properties. The height and width
increments (specified in character units) are added to or subtracted from the size of the key box. This isuseful mainly when you want larger borders around the key entries.
By default the key is built up one plot at a time. That is, the key symbol and title are drawn at the sametime as the corresponding plot. That means newer plots may sometimes place elements on top of the key.
set key opaque causes the key to be generated after all the plots. In this case the key area is filled withbackground color or the requested fill color and then the key symbols and titles are written. The default canbe restored by set key noopaque.
The text in the key uses enhanced mode by default. This can be suppressed by the noenhanced keyword
applied to the entire key, to the key title only, or to individual plot titles.
set key default restores the default key configuration.
set key notitle
set key nobox noopaque
set key fixed right top vertical Right noreverse enhanced autotitle
set key noinvert samplen 4 spacing 1 width 0 height 0
set key maxcolumns 0 maxrows 0

3D keyPlacement of the key for 3D plots (splot) by default uses the fixed option. This is very similar to insideplacement with one important difference. The plot boundaries of a 3D plot change as the view point isrotated or scaled. If the key is positioned inside these boundaries then the key also moves when the view ischanged. fixed positioning ignores changes to the view angles or scaling; i.e. the key remains fixed in one
location on the canvas as the plot is rotated.
For 2D plots the fixed option is exactly equivalent to inside.
If splot is being used to draw contours, by default a separate key entry is generated for each contour levelwith a distinct line type. To modify this see set cntrlabel (p. 156).
Key examples
This places the key at the default location:
set key default

This places a key at a specific place (upper right) on the screen:
set key at screen 0.85, 0.85

This places the key below the graph and minimizes the vertical space taken:

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set key below horizontal

This places the key in the bottom left corner of the plot, left-justifies the text, gives the key box a title atthe top, and draws a box around it with a thick border:
set key left bottom Left title 'Legend' box lw 3

Extra key entries
Normally each plot autogenerates a single line entry in
the key. If you need more control over what appears
in the key you can use the keyentry keyword in theplot or splot command to insert extra lines. Instead ofproviding a filename or function to plot, use keyentry as
a placeholder followed by plot style information (used togenerate a key symbol) and a title. All the usual options
for title font, text color, at coordinates, and enhanced
text markup apply. Example:

Construct key from custom entries
0

1

2

3

4

0
1
2

Outcomes
no effect
thresholdtypical range
as reported in [12]strong effect3

set key outside right centerplot $HEATMAP matrix with image notitle, \keyentry "Outcomes" left, \keyentry with boxes fc palette cb 0 title "no effect", \keyentry with boxes fc palette cb 1 title "threshold", \keyentry with boxes fc palette cb 3 title "typical range", \keyentry
title "as reported in [12]", \keyentry with boxes fc palette cb 5 title "strong effect"

The line generated by keyentry "Outcomes" left places left-justified text in the space that would normallyhold the sample. This allows an embedded title that may span the full width of the key. If a title is given
also in the same keyentry then both strings appear on the same line, allowing generation of two-column key
entries. You can use keywords left/right/center for justification, boxed, etc. Example:
plot ..., keyentry "West Linn" boxed title "locations"

Key autotitle
set key autotitle causes each plot to be identified in the key by the name of the data file or function usedin the plot command. This is the default. set key noautotitle disables the automatic generation of plot
titles. The command set key autotitle columnheader causes the first entry in each column of input data
to be interpreted as a text string and used as a title for the corresponding plot. If the quantity being plotted
is a function of data from several columns, gnuplot may be confused as to which column to draw the title
from. In this case it is necessary to specify the column explicitly in the plot command, e.g.
plot "datafile" using (($2+$3)/$4) title columnhead(3) with lines

Note: The effect of set key autotitle columnheader, treatment of the first line in a data file as column
headers rather than data applies even if the key is disabled by unset key. It also applies to stats and fit
commands even though they generate no key. If you want the first line of data to be treated as column
headers but not to use them for plot titles, use set datafile columnheaders.
In all cases an explicit title or notitle keyword in the plot command itself will override the default fromset key autotitle.
Key layout
Key layout options:178

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set key {vertical | horizontal}{maxcols {<max no. of columns> | auto}}{maxrows {<max no. of rows> | auto}}{columns <exact no. of columns>}{keywidth [screen|graph] <fraction>}{Left | Right}{{no}reverse} {{no}invert}{samplen <sample_length>} {spacing <line_spacing>}{width <width_increment>} {height <height_increment>}{title {"<text>"} {{no}enhanced} {center | left | right}}{font "<face>,<size>"} {textcolor <colorspec>}

Automatic arrangement of elements within the key into rows and columns is affected by the keywords shown
above. The default is vertical, for which the key uses the fewest columns possible. Elements are aligned ina column until there is no more vertical space, at which point a new column is started. The vertical space
may be limited using ’maxrows’. In the case of horizontal, the key instead uses the fewest rows possible.
The horizontal space may be limited using ’maxcols’.
The auto-selected number of rows and columns may be unsatisfactory. You can specify a definite number ofcolumns using set key columns <N>. In this case you may need to adjust the sample widths (samplen)
and the total key width (keywidth).
By default the first plot label is at the top of the key and successive labels are entered below it. The invert
option causes the first label to be placed at the bottom of the key, with successive labels entered above it.
This option is useful to force the vertical ordering of labels in the key to match the order of box types in astacked histogram.
set key title "text" places an overall title at the top of the key. Font, text justification, and other text
properties specific to the title can be specified by placing the required keywords immediately after the "text"
in this command. Font or text properties specified elsewhere apply to all text in the key.
The default layout places a style sample (color, line, point, shape, etc) at the left of the key entry line,
and the title text at the right. The text and sample positions can be swapped using the reverse keyword.
Text justification of the individual plot titles within the key is controlled by Left or Right (default). The
horizontal extend of the style sample can be set to an approximate number of character width (samplen).
When using the TeX/LaTeX group of terminals or terminals in which formatting information is embeddedin the string, gnuplot is bad at estimating the amount of space required, so the automatic key layout may
be poor. If the key is to be positioned at the left, it may help to use the combination set key left Leftreverse and force the appropriate number of columns or total key width.
Key placement
Key placement options:set key {inside | outside | fixed}{lmargin | rmargin | tmargin | bmargin}{at <position>}}{left | right | center} {top | bottom | center}{offset <dx>,<dy>}This section describes placement of the primary, auto-generated key. To construct a secondary key or place
plot titles elsewhere, see multiple keys (p. 179).
To understand positioning, the best concept is tothink of a region, i.e., inside/outside, or one of
the margins.
Along with the region, keywords
t/l
t/c
t/r
left/center/right (l/c/r) and top/center/bottom
c/l
c
c/r
(t/c/b) control where within the particular region the
b/l
b/c
b/r
key should be placed. In inside mode, the keywords
left (l), right (r), top (t), bottom (b), and center(c) push the key out toward the plot boundary as illustrated here:gnuplot 6.0

179

In outside mode, automatic placement is similar to the above illustration, but with respect to the view,
rather than the graph boundary. That is, a border is moved inward to make room for the key outside of theplotting area, although this may interfere with other labels and may cause an error on some devices. The
particular plot border that is moved depends upon the position described above and the stacking direction.
For options centered in one of the dimensions, there is no ambiguity about which border to move. For thecorners, when the stack direction is vertical, the left or right border is moved inward appropriately. Whenthe stack direction is horizontal, the top or bottom border is moved inward appropriately.
The margin syntax allows automatic placement of key
regardless of stack direction. When one of the marl/tm c/tm r/tm
gins lmargin (lm), rmargin (rm), tmargin (tm),
t/lm
t/rm
and bmargin (bm) is combined with a single, nonc/lm
c/rm
conflicting direction keyword, the key is positioned
b/lm
b/rm
along the outside of the page as shown here. Keyl/bm
c/bm
r/bm
words above and over are synonymous with tmargin. Keywords below and under are synonymouswith bmargin.
For version compatibility, above, over, below, or under without any additional l/c/r or stack direction
keyword uses center and horizontal. The keyword outside without any additional t/b/c or stack direction
keyword uses top, right and vertical (i.e., the same as t/rm above).
The <position> can be a simple x,y,z as in previous versions, but these can be preceded by one of five
keywords (first, second, graph, screen, character) which selects the coordinate system in which theposition of the first sample line is specified. See coordinates (p. 33) for more details. The effect ofleft, right, top, bottom, and center when <position> is given is to align the key as though it were text
positioned using the label command, i.e., left means left align with key to the right of <position>, etc.
Key offset
Regardless of the key placement options chosen, the final position of the key can be adjusted manually by
specifying an offset. As usual, the x and y components of the offset may be given in character, graph, orscreen coordinates.
Key samples
By default, each plot on the graph generates a corresponding entry in the key. This entry contains a plot
title and a sample line/point/box of the same color and fill properties as used in the plot itself. The font
and textcolor properties control the appearance of the individual plot titles that appear in the key. Setting
the textcolor to "variable" causes the text for each key entry to be the same color as the line or fill color forthat plot. This was the default in some earlier versions of gnuplot.
The length of the sample line can be controlled by samplen. The sample length is computed as the sum of
the tic length and <sample length> times the character width. It also affects the positions of point samples
in the key since these are drawn at the midpoint of the sample line, even if the line itself is not drawn.
Key entry lines are single-spaced based on the current font size. This can be adjusted by set key spacing<line-spacing>.
The <width increment> is a number of character widths to be added to or subtracted from the length of thestring. This is useful only when you are putting a box around the key and you are using control charactersin the text. gnuplot simply counts the number of characters in the string when computing the box width;
this allows you to correct it.
Multiple keys

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It is possible to construct a legend/key manually rather
than having the plot titles all appear in the autogenerated key. This allows, for example, creating a single
legend for the component panels in a multiplot.

Illustrate use of a custom key area

set multiplot layout 3,2 columnsfirstset style data boxes
plot $D using 0:6 lt 1 title at 0.75, 0.20
plot $D using 0:12 lt 2 title at 0.75, 0.17
plot $D using 0:13 lt 3 title at 0.75, 0.14
plot $D using 0:14 lt 4 title at 0.75, 0.11
set label 1 at screen 0.75, screen 0.22 "Custom combined key area"
plot $D using 0:($6+$12+$13+$14) with linespoints title "total"
unset multiplot

total1900 1910 1920 1930 1940 1950 1960 1970

Custom combined key area
Denmark
Netherlands
NorwaySwedenLabel
Arbitrary labels can be placed on the plot using the set label command.
Syntax:set label {<tag>} {"<label text>"} {at <position>}{left | center | right}{norotate | rotate {by <degrees>}}{font "<name>{,<size>}"}{noenhanced}{front | back}{textcolor <colorspec>}{point <pointstyle> | nopoint}{offset <offset>}{nobox} {boxed {bs <boxstyle>}}{hypertext}
unset label {<tag>}show label

The <position> is specified by either x,y or x,y,z, and may be preceded by first, second, polar, graph,screen, or character to indicate the coordinate system. See coordinates (p. 33) for details.
The tag is an integer that is used to identify the label. If no <tag> is given, the lowest unused tag value isassigned automatically. The tag can be used to delete or modify a specific label. To change any attribute ofan existing label, use the set label command with the appropriate tag, and specify the parts of the label tobe changed.
The <label text> can be a string constant, a string variable, or a string- valued expression. See strings(p. 65), sprintf (p. 41), and gprintf (p. 169).
By default, the text is placed flush left against the point x,y,z. To adjust the way the label is positioned withrespect to the point x,y,z, add the justification parameter, which may be left, right or center, indicatingthat the point is to be at the left, right or center of the text. Labels outside the plotted boundaries are
permitted but may interfere with axis labels or other text.
Some terminals support enclosing the label in a box. See set style textbox (p. 221). Not all terminals
can handle boxes for rotated text.
If rotate is given, the label is written vertically. If rotate by <degrees> is given, the baseline of the text
will be set to the specified angle. Some terminals do not support text rotation.
Font and its size can be chosen explicitly by font "<name>{,<size>}" if the terminal supports fontsettings. Otherwise the default font of the terminal will be used.
Normally the enhanced text mode string interpretation, if enabled for the current terminal, is applied to all
text strings including label text. The noenhanced property can be used to exempt a specific label fromthe enhanced text mode processing. The can be useful if the label contains underscores, for example. Seeenhanced text (p. 34).

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181

If front is given, the label is written on top of the graphed data. If back is given (the default), the label iswritten underneath the graphed data. Using front will prevent a label from being obscured by dense data.
textcolor <colorspec> changes the color of the label text. <colorspec> can be a linetype, an rgb color,or a palette mapping. See help for colorspec (p. 57) and palette (p. 42). textcolor may be abbreviatedtc.
`tc default` resets the text color to its default state.
`tc lt <n>` sets the text color to that of line type <n>.
`tc ls <n>` sets the text color to that of line style <n>.
`tc palette z` selects a palette color corresponding to the label z position.
`tc palette cb <val>` selects a color corresponding to <val> on the colorbox.
`tc palette fraction <val>`, with 0<=val<=1, selects a color corresponding to
the mapping [0:1] to grays/colors of the `palette`.
`tc rgb "#RRGGBB"` or `tc rgb "0xRRGGBB"` sets an arbitrary 24-bit RGB color.
`tc rgb 0xRRGGBB` As above; a hexadecimal constant does not require quotes.

If a <pointstyle> is given, using keywords lt, pt and ps, see style (p. 143), a point with the given styleand color of the given line type is plotted at the label position and the text of the label is displaced slightly.
This option is used by default for placing labels in mouse enhanced terminals. Use nopoint to turn off thedrawing of a point near the label (this is the default).
The displacement defaults to 1,1 in pointsize units if a <pointstyle> is given, 0,0 if no <pointstyle> isgiven. The displacement can be controlled by the optional offset <offset> where <offset> is specified
by either x,y or x,y,z, and may be preceded by first, second, graph, screen, or character to select thecoordinate system. See coordinates (p. 33) for details.
If one (or more) axis is timeseries, the appropriate coordinate should be given as a quoted time string
according to the timefmt format string. See set xdata (p. 231) and set timefmt (p. 225).
The options available for set label are also available for the labels plot style. See labels (p. 87). In thiscase the properties textcolor, rotate, and pointsize may be followed by keyword variable rather thanby a fixed value. In this case the corresponding property of individual labels is determined by additional
columns in the using specifier.
ExamplesExamples:To set a label at (1,2) to "y=x", use:
set label "y=x" at 1,2

To set a Sigma of size 24, from the Symbol font set, at the center of the graph, use:
set label "S" at graph 0.5,0.5 center font "Symbol,24"

To set a label "y=x^2" with the right of the text at (2,3,4), and tag the label as number 3, use:
set label 3 "y=x^2" at 2,3,4 right

To change the preceding label to center justification, use:
set label 3 center

To delete label number 2, use:
unset label 2

To delete all labels, use:
unset label

To show all labels (in tag order), use:show label

To set a label on a graph with a timeseries on the x axis, use, for example:

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set timefmt "%d/%m/%y,%H:%M"
set label "Harvest" at "25/8/93",1

To display a freshly fitted parameter on the plot with the data and the fitted function, do this after the fit,
but before the plot:
set label sprintf("a = %3.5g",par_a) at 30,15
bfit = gprintf("b = %s*10^%S",par_b)
set label bfit at 30,20

To display a function definition along with its fitted parameters, use:f(x)=a+b*x
fit f(x) 'datafile' via a,b
set label GPFUN_f at graph .05,.95
set label sprintf("a = %g", a) at graph .05,.90
set label sprintf("b = %g", b) at graph .05,.85

To set a label displaced a little bit from a small point:
set label 'origin' at 0,0 point lt 1 pt 2 ps 3 offset 1,-1

To set a label whose color matches the z value (in this case 5.5) of some point on a 3D splot colored using
pm3d:
set label 'text' at 0,0,5.5 tc palette z

Hypertext
Some terminals (wxt, qt, svg, canvas, win) allow you to attach hypertext to specific points on the graph orelsewhere on the canvas. When the mouse hovers over the anchor point, a pop-up box containing the text
is displayed. Terminals that do not support hypertext will display nothing. You must enable the point
attribute of the label in order for the hypertext to be anchored. Enhanced text markup is not applied to
hypertext labels. Examples:
set label at 0,0 "Plot origin" hypertext point pt 1
plot 'data' using 1:2:0 with labels hypertext point pt 7 \title 'mouse over point to see its order in data set'
# mousing over any point of this pm3d surface will display# its Z coordinate as hypertext
splot '++' using 1:2:(F($1,$2)) with pm3d, \'++' using 1:2:(F($1,$2)):(sprintf("%.3f", F($1,$2))) with labels \hypertext point lc rgb "0xff000000" notitle

For the wxt and qt terminals, left-click on a hypertext anchor after the text has appeared will copy thehypertext to the clipboard.
EXPERIMENTAL(implementation
detailsmaychange)
Text
of
the
form
"image{<xsize>,<ysize>}:<filename>{\n<caption text>}" will trigger display of the image file in a
pop-up box. The optional size overrides a default box size 300x200. The types of image file recognized
may vary by terminal type, but *.png should always work. Any additional text lines following the image
filename are displayed as usual for hypertext. Example:
set label 7 "image:../figures/Fig7_inset.png\nFigure 7 caption..."set label 7 at 10,100 hypertext point pt 7

Linetype
The set linetype command allows you to redefine the basic linetypes used for plots. The command options
are identical to those for "set style line". Unlike line styles, redefinitions by set linetype are persistent.
They are not affected by reset. However the initial linetype properties are restored by reset session.
For example, whatever linetypes one and two look like to begin with, if you redefine them like this:gnuplot 6.0

183

set linetype 1 lw 2 lc rgb "blue" pointtype 6
set linetype 2 lw 2 lc rgb "forest-green" pointtype 8

everywhere that uses lt 1 will now get a thick blue line. This includes uses such as the definition of atemporary linestyle derived from the base linetype 1. Similarly lt 2 will now produce a thick green line.
This mechanism can be used to define a set of personal preferences for the sequence of lines used in gnuplot.
The recommended way to do this is to add to the run-time initialization file ˜ /.gnuplot a sequence ofcommands likeset linetype 1 lc rgb "dark-violet" lw 2 pt 1
set linetype 2 lc rgb "sea-green"lw 2 pt 7
set linetype 3 lc rgb "cyan"lw 2 pt 6 pi -1
set linetype 4 lc rgb "dark-red"lw 2 pt 5 pi -1
set linetype 5 lc rgb "blue"lw 2 pt 8
set linetype 6 lc rgb "dark-orange" lw 2 pt 3
set linetype 7 lc rgb "black"lw 2 pt 11
set linetype 8 lc rgb "goldenrod"
lw 2
set linetype cycle 8

Every time you run gnuplot the line types will be initialized to these values. You may initialize as many
linetypes as you like. If you do not redefine, say, linetype 3 then it will continue to have the default properties(in this case blue, pt 3, lw 1, etc).
Similar script files can be used to define theme-based color choices, or sets of colors optimized for a particularplot type or output device.
The command set linetype cycle 8 tells gnuplot to re-use these definitions for the color and linewidth ofhigher-numbered linetypes. That is, linetypes 9-16, 17-24, and so on will use this same sequence of colors
and widths. The point properties (pointtype, pointsize, pointinterval) are not affected by this command.
unset linetype cycle disables this feature. If the line properties of a higher numbered linetype are explicitly
defined, this takes precedence over the recycled low-number linetype properties.

Link
Syntax:set link {x2 | y2} {via <expression1> inverse <expression2>}
unset link

The set link command establishes a mapping between the x and x2 axes, or the y and y2 axes.
<expression1> maps primary axis coordinates onto the secondary axis. <expression2> maps secondary
axis coordinates onto the primary axis.
Examples:set link x2

This is the simplest form of the command. It forces the x2 axis to have identically the same range, scale,and direction as the x axis. Commands set xrange, set x2range, set auto x, etc will affect both the x
and x2 axes.
set link x2 via x**2 inverse sqrt(x)plot "sqrt_data" using 1:2 axes x2y1, "linear_data" using 1:2 axes x1y1

This command establishes forward and reverse mapping between the x and x2 axes. The forward mappingis used to generate x2 tic labels and x2 mouse coordinate The reverse mapping is used to plot coordinates
given in the x2 coordinate system. Note that the mapping as given is valid only for x non-negative. When
mapping to the y2 axis, both <expression1> and <expression2> must use y as dummy variable.

Lmargin
The command set lmargin sets the size of the left margin. Please see set margin (p. 185) for details.

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Loadpath
The loadpath setting defines additional locations for data and command files searched by the call, load,plot and splot commands. If a file cannot be found in the current directory, the directories in loadpath
are tried.
Syntax:set loadpath {"pathlist1" {"pathlist2"...}}
show loadpath

Path names may be entered as single directory names, or as a list of path names separated by a platformspecific path separator, eg. colon (’:’) on Unix, semicolon (’;’) on DOS/Windows/OS/2 platforms. The show
loadpath, save and save set commands replace the platform-specific separator with a space character (’’).
If the environment variable GNUPLOT LIB is set, its contents are appended to loadpath. However, show
loadpath prints the contents of set loadpath and GNUPLOT LIB separately. Also, the save and saveset commands ignore the contents of GNUPLOT LIB.

LocaleThe locale setting determines the language with which {x,y,z}{d,m}tics will write the days and months.
Syntax:set locale {"<locale>"}<locale> may be any language designation acceptable to your installation. See your system documentation
for the available options. The command set locale "" will try to determine the locale from the LC TIME,LC ALL, or LANG environment variables.
To change the decimal point locale, see set decimalsign (p. 163). To change the character encoding to
the current locale, see set encoding (p. 166).

Logscale
Syntax:set logscale <axes> {<base>}
unset logscale <axes>
show logscale

where <axes> may be any combinations of x, x2, y, y2, z, cb, and r in any order. <base> is the baseof the log scaling (default is base 10). If no axes are specified, the command affects all axes except r. The
command unset logscale turns off log scaling for all axes. Note that the ticmarks generated for logscaled
axes are not uniformly spaced. See set xtics (p. 235).
Examples:To enable log scaling in both x and z axes:
set logscale xz

To enable scaling log base 2 of the y axis:
set logscale y 2

To enable z and color log axes for a pm3d plot:
set logscale zcb

To disable z axis log scaling:
unset logscale zgnuplot 6.0

185MacrosIn this version of gnuplot macro substitution is always enabled. Tokens in the command line of the form@<stringvariablename> will be replaced by the text string contained in <stringvariablename>. See substitution (p. 66).

Mapping
If data are provided to splot in spherical or cylindrical coordinates, the set mapping command should be
used to instruct gnuplot how to interpret them.
Syntax:set mapping {cartesian | spherical | cylindrical}

A cartesian coordinate system is used by default.
For a spherical coordinate system, the data occupy two or three columns (or using entries). The first two
are interpreted as the azimuthal and polar angles theta and phi (or "longitude" and "latitude"), in the units
specified by set angles. The radius r is taken from the third column if there is one, or is set to unity if
there is no third column. The mapping is:
x = r * cos(theta) * cos(phi)y = r * sin(theta) * cos(phi)z = r * sin(phi)Note that this is a "geographic" spherical system, rather than a "polar" one (that is, phi is measured fromthe equator, rather than the pole).
For a cylindrical coordinate system, the data again occupy two or three columns. The first two are interpreted
as theta (in the units specified by set angles) and z. The radius is either taken from the third column or
set to unity, as in the spherical case. The mapping is:
x = r * cos(theta)y = r * sin(theta)z = zThe effects of mapping can be duplicated with the using specifier of the splot command, but mapping
may be more convenient if many data files are to be processed. However even if mapping is used, using
may still be necessary if the data in the file are not in the required order.
mapping has no effect on plot. world.dem:

mapping demos.

MarginThe margin is the distance between the plot border and the outer edge of the canvas. The size of the margin
is chosen automatically, but can be overridden by the set margin commands. show margin shows thecurrent settings. To alter the distance between the inside of the plot border and the data in the plot itself,
see set offsets (p. 196).
Syntax:set lmargin {{at screen} <margin>}
set rmargin {{at screen} <margin>}
set tmargin {{at screen} <margin>}
set bmargin {{at screen} <margin>}
set margins <left>, <right>, <bottom>, <top>show margin

The default units of <margin> are character heights or widths, as appropriate. A positive value defines theabsolute size of the margin. A negative value (or none) causes gnuplot to revert to the computed value.
For 3D plots, only the left margin can be set using character units.

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The keywords at screen indicates that the margin is specified as a fraction of the full drawing area. Thiscan be used to precisely line up the corners of individual 2D and 3D graphs in a multiplot. This placement
ignores the current values of set origin and set size, and is intended as an alternative method for positioning
graphs within a multiplot.
Normally the margins of a plot are automatically calculated based on tics, tic labels, axis labels, the plot
title, the timestamp and the size of the key if it is outside the borders. If, however, tics are attached to theaxes (set xtics axis, for example), neither the tics themselves nor their labels will be included in either themargin calculation or the calculation of the positions of other text to be written in the margin. This canlead to tic labels overwriting other text if the axis is very close to the border.

Micro
By default the "%c" format specifier for scientific notation used to generate axis tick labels uses a lower
case u as a prefix to indicate "micro" (10^-6). The set micro command tells gnuplot to use a different
typographic character (unicode U+00B5). The byte sequence used to represent this character depends onthe current encoding. See format specifiers (p. 169), encoding (p. 166).
If the current encoding default is not satisfactory, you can provide a character string that generates thedesired representation. This is mostly useful for latex terminals, for example
set micro "{\textmu}"

Minussign
Gnuplot uses the C language library routine sprintf() for most formatted input. However it also has its
own formatting routine gprintf() that is used to generate axis tic labels. The C library routine always
use a hyphen character (ascii \055) to indicate a negative number, as in -7. Many people prefer a different
typographic minus sign character (unicode U+2212) for this purpose, as in −7. The commandset minussign

causes gprintf() to use this minus sign character rather than a hyphen in numeric output. In a utf-8 locale
this is the multibyte sequence corresponding to unicode U+2212. In a Window codepage 1252 locale this is
the 8-bit character ALT+150 ("en dash"). The set minussign command will affect axis tic labels and anylabels that are created by explicitly invoking gprintf. It has no effect on other strings that contain a hyphen.
See gprintf (p. 169).
Note that this command is ignored when you are using any of the LaTeX terminals, as LaTeX has its own
mechanism for handling minus signs. It also is not necessary when using the postscript terminal because thepostscript prologue output by gnuplot remaps the ascii hyphen code \055 to a different glyph named minus.
Example (assumes utf8 locale):
set minus
A = -5print "A = ",A# printed string will contain a hyphen
print gprintf("A = %g",A)# printed string will contain character U+2212
set label "V = -5"# label will contain a hyphen
set label sprintf("V = %g",-5) # label will contain a hyphen
set label gprintf("V = %g",-5) # label will contain character U+2212

Monochrome
Syntax:set monochrome {linetype N <linetype properties>}

The set monochrome command selects an alternative set of linetypes that differ by dot/dash pattern orline width rather than by color. This command replaces the monochrome option offered by certain terminal
types in earlier versions of gnuplot. For backward compatibility these terminal types now implicitly invoke"set monochrome" if their own "mono" option is present. For example,

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187

set terminal pdf monois equivalent to
set terminal pdf
set mono

Selecting monochrome mode does not prevent you from explicitly drawing lines using RGB or palette colors,
but see also set palette gray (p. 201). Six monochrome linetypes are defined by default. You can change
their properties or add additional monochrome linetypes by using the full form of the command. Changes
made to the monochrome linetypes do not affect the color linetypes and vice versa. To restore the usual setof color linetypes, use either unset monochrome or set color.

Mouse
The command set mouse enables mouse actions for the current interactive terminal. It is enabled bydefault.
There are two mouse modes. The 2D mode works for plot commands and for splot maps (i.e. set view
with z-rotation 0, 90, 180, 270 or 360 degrees, including set view map). In this mode the mouse position istracked and you can pan or zoom using the mouse buttons or arrow keys. Some terminals support toggling
individual plots on/off by clicking on the corresponding key title or on a separate widget.
For 3D graphs splot, the view and scaling of the graph can be changed with mouse buttons 1 and 2,
respectively. A vertical motion of Button 2 with the shift key held down changes the xyplane. If additionallyto these buttons the modifier <ctrl> is held down, the coordinate axes are displayed but the data aresuppressed. This is useful for large data sets. Mouse button 3 controls the azimuth of the z axis (see setview azimuth (p. 229)).
Mousing coordinate readout in multiplot mode is displayed only with for the most recent plot within themultiplot. See new multiplots (p. 27).
Syntax:set mouse {doubleclick <ms>} {nodoubleclick}{{no}zoomcoordinates}{zoomfactors <xmultiplier>, <ymultiplier>}{noruler | ruler {at x,y}}{polardistance{deg|tan} | nopolardistance}{format <string>}{mouseformat <int> | <string> | function <f(x,y)>}{{no}labels {"labeloptions"}}{{no}zoomjump} {{no}verbose}
unset mouse

The options noruler and ruler switch the ruler off and on, the latter optionally setting the origin at thegiven coordinates. While the ruler is on, the distance in user units from the ruler origin to the mouse isdisplayed continuously. By default, toggling the ruler has the key binding ’r’.
The option polardistance determines if the distance between the mouse cursor and the ruler is also shownin polar coordinates (distance and angle in degrees or tangent (slope)). This corresponds to the default key
binding ’5’.
Choose the option labels to define persistent gnuplot labels using Button 2. The default is nolabels, whichmakes Button 2 draw only a temporary label at the mouse position. Labels are drawn with the current
setting of mouseformat. The labeloptions string is passed to the set label command. The default is"point pointtype 1" which will plot a small plus at the label position. Temporary labels will disappear at
the next replot or mouse zoom operation. Persistent labels can be removed by holding the Ctrl-Key down
while clicking Button 2 on the label’s point. The threshold for how close you must be to the label is also
determined by the pointsize.
If the option verbose is turned on the communication commands are shown during execution. This option
can also be toggled by hitting 6 in the driver’s window. verbose is off by default.

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Press ’h’ in the driver’s window for a summary of the mouse and key bindings. This will also display user
defined bindings or hotkeys defined by the bind command. Note that user defined binding may overridedefault bindings. See also help for bind (p. 61).
Doubleclick
The doubleclick resolution is given in milliseconds and used for Button 1, which copies the current mouseposition to the clipboard on some terminals. The default value is 300 ms. Setting the value to 0 ms triggers
the copy on a single click.
FormatThe set mouse format command specifies a format string for sprintf() which determines how the mouse
cursor [x,y] coordinates are printed to the plot window and to the clipboard. The default is "% #g".
This setting is superseded by "set mouse mouseformat".
Mouseformat
Syntax:set mouse mouseformat iset mouse mouseformat "custom format"
set mouse mouseformat function string_valued_function(x, y)This command controls the format used to report the current mouse position. An integer argument selects
one of the format options in the table below. A string argument is used as a format for sprintf() in option 7
and should contain two float specifiers, one for x and one for y.
Use of a custom function returning a string is EXPERIMENTAL. It allows readout of coordinate systems
in which inverse mapping from screen coordinates to plot coordinates requires joint consideration of both x
and y. See for example the map projection demo.
Example:set mouse mouseformat "mouse x,y = %5.2g, %10.3f"

Use set mouse mouseformat "" to turn this string off again.
The following formats are available:
0
1
2
3
4
5
6
7
8

default (same as 1)
axis coordinates
1.23, 2.45
graph coordinates (from 0 to 1)/0.00, 1.00/
x = timefmt
y = axis[(as set by `set timefmt`), 2.45]
x = datey = axis[31. 12. 1999, 2.45]
x = timey = axis[23:59, 2.45]
x = date timey = axis[31. 12. 1999 23:59, 2.45]
format from `set mouse mouseformat <format-string>`
format from `set mouse mouseformat function <func>`

Scrolling
The mouse wheel adjusts x and y axis ranges in both 2D and 3D plots. Each adjustment increment is
10% of the current range by default. This may be changed by set mouse zoomfactor <x-multiplier>,<y-multiplier>.
• <wheel-up> scrolls y and y2 axis ranges up by a fraction of the current range• <wheel-down> scrolls y and y2 ranges down by a fraction of the current range• <shift+wheel-up> scrolls left (decreases x and x2 ranges)

gnuplot 6.0

189• <shift+wheel-down> scrolls right (increases x and x2 ranges)• <control+wheel-up> zooms in around the current mouse position• <control+wheel-down> zooms out around the current mouse position• <shift+control+wheel-up> zooms in only along x and x2 (pinch)• <shift+control+wheel-down> zooms out only along x and x2 (expand)Zoom
Proportional zoom in/out around the current mouse position is controlled by the mouse wheel (see scrolling(p. 188)).
Enlarging a selected region in a 2D plot is accomplished by holding down the left mouse button and dragging
the mouse to delineate a zoom region. The original plot can be restored by typing the ’u’ hotkey in the plot
window. Hotkeys ’p’ and ’n’ step back and forth through a history of zoom operations.
The option zoomcoordinates determines if the coordinates of the zoom box are drawn at the edges whilezooming. This is on by default.
If the option zoomjump is on, the mouse pointer will automatically offset a small distance after starting azoom region with button 3. This can be useful to avoid a tiny (or even empty) zoom region. zoomjump is
off by default.

MtticsMinor tic marks around the perimeter of a polar plot are controlled by by set mttics. Please see set mxtics(p. 191).

Multiplot
The command set multiplot places gnuplot in multiplot mode, in which several plots are placed next toeach other on the same page or screen window.
Syntax:set multiplot{ title <page title> {font <fontspec>} {enhanced|noenhanced} }{ layout <rows>,<cols>{rowsfirst|columnsfirst} {downwards|upwards}{scale <xscale>{,<yscale>}} {offset <xoff>{,<yoff>}}{margins <left>,<right>,<bottom>,<top>}{spacing <xspacing>{,<yspacing>}}}
set multiplot {next|previous}
unset multiplot

For some terminals, no plot is displayed until the command unset multiplot is given, which causes theentire page to be drawn and then returns gnuplot to its normal single-plot mode. For other terminals, eachseparate plot command produces an updated display.
The clear command is used to erase the rectangular area of the page that will be used for the next plot.
This is typically needed to inset a small plot inside a larger plot.
Any labels or arrows that have been defined will be drawn for each plot according to the current size andorigin (unless their coordinates are defined in the screen system). Just about everything else that can be
set is applied to each plot, too. If you want something to appear only once on the page, for instance asingle time stamp, you’ll need to put a set time/unset time pair around one of the plot, splot or replot
commands within the set multiplot/unset multiplot block.

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The multiplot title is separate from the individual plot titles, if any. Space is reserved for it at the top of
the page, spanning the full width of the canvas.
The commands set origin and set size must be used to correctly position each plot if no layout is specified
or if fine tuning is desired. See set origin (p. 196) and set size (p. 213) for details of their usage.
Example:set multiplot
set size 0.4,0.4
set origin 0.1,0.1
plot sin(x)set size 0.2,0.2
set origin 0.5,0.5
plot cos(x)unset multiplot

This displays a plot of cos(x) stacked above a plot of sin(x).
set size and set origin refer to the entire plotting area used for each plot. Please also see set term size(p. 32). If you want to have the axes themselves line up, you can guarantee that the margins are the same
size with the set margin commands. See set margin (p. 185) for their use. Note that the margin settings
are absolute, in character units, so the appearance of the graph in the remaining space will depend on thescreen size of the display device, e.g., perhaps quite different on a video display and a printer.
With the layout option you can generate simple multiplots without having to give the set size and set
origin commands before each plot: Those are generated automatically, but can be overridden at any time.
With layout the display will be divided by a grid with <rows> rows and <cols> columns. This grid isfilled rows first or columns first depending on whether the corresponding option is given in the multiplot
command. The stack of plots can grow downwards or upwards. Default is rowsfirst and downwards.
The commands set multiplot next and set multiplot previous are relevant only in the context of using
the layout option. next skips the next position in the grid, leaving a blank space. prev returns to the grid
position immediately preceding the most recently plotted position.
Each plot can be scaled by scale and shifted with offset; if the y-values for scale or offset are omitted, thex-value will be used. unset multiplot will turn off the automatic layout and restore the values of set sizeand set origin as they were before set multiplot layout.
Example:set size 1,1
set origin 0,0
set multiplot layout 3,2 columnsfirst scale 1.1,0.9[ up to 6 plot commands here ]unset multiplot

The above example will produce 6 plots in 2 columns filled top to bottom, left to right. Each plot will havea horizontal size of 1.1/2 and a vertical size of 0.9/3.
Another possibility is to set uniform margins for all plots in the layout with options layout margins andspacing, which must be used together. With margins you set the outer margins of the whole multiplot
grid.
spacing gives the gap size between two adjacent subplots, and can also be given in character or screen
units. If a single value is given, it is used for both x and y direction, otherwise two different values can beselected.
If one value has no unit, the one of the preceding margin setting is used.
Example:set multiplot layout 2,2 margins 0.1, 0.9, 0.1, 0.9 spacing 0.0

In this case the two left-most subplots will have left boundaries at screen coordinate 0.1, the two right-most
subplots will have right boundaries at screen coordinate 0.9, and so on. Because the spacing between subplots
is given as 0, their inner boundaries will superimpose.
Example:gnuplot 6.0

191

set multiplot layout 2,2 margins char 5,1,1,2 spacing screen 0, char 2This produces a layout in which the boundary of both left subplots is 5 character widths from the left edgeof the canvas, the right boundary of the right subplots is 1 character width from the canvas edge. The
overall bottom margin is one character height and the overall top margin is 2 character heights. There is
no horizontal gap between the two columns of subplots. The vertical gap between subplots is equal to 2
character heights.
Example:set multiplot layout 2,2 columnsfirst margins 0.1,0.9,0.1,0.9 spacing 0.1
set ylabel 'ylabel'plot sin(x)set xlabel 'xlabel'plot cos(x)unset ylabel
unset xlabel
plot sin(2*x)
set xlabel 'xlabel'plot cos(2*x)
unset multiplot

See also remultiplot (p. 147), new multiplots (p. 27), multiplot demo (multiplt.dem)

Mx2tics
Minor tic marks along the x2 (top) axis are controlled by set mx2tics. Please see set mxtics (p. 191).

MxticsMinor tic marks along the x axis are controlled by set mxtics. They can be turned off with unset mxtics.
Similar commands control minor tics along the other axes.
Syntax:set mxtics <freq>
set mxtics default
set mxtics time <N> <units>
unset mxtics
show mxtics

The same syntax applies to mytics, mztics, mx2tics, my2tics, mrtics, mttics and mcbtics.
<freq> is the number of sub-intervals (NOT the number of minor tic marks) between major tics. The default
for a linear axis is either 2 (one mark) or 5 (four marks) depending on the spacing of the major tics.
default will return the number of minor ticks to its default value.
set mxtics time <N> <units> applies only when the major tics are set to time mode. See set mxtics
time (p. 192).
If the axis is logarithmic, the number of sub-intervals will be set to a reasonable number by default (based
upon the length of a decade). This will be overridden if <freq> is given. However the usual minor tics (2,3, ..., 8, 9 between 1 and 10, for example) are obtained by setting <freq> to 10, even though there are but
nine sub-intervals.
To set minor tics at arbitrary positions, use the ("<label>" <pos> <level>, ...)
{x|x2|y|y2|z}tics with <label> empty and <level> set to 1.

form of set

The set m{x|x2|y|y2|z}tics commands work only when there are uniformly spaced major tics. If all major
tics were placed explicitly by set {x|x2|y|y2|z}tics, then minor tic commands are ignored. Implicit major
tics and explicit minor tics can be combined using set {x|x2|y|y2|z}tics and set {x|x2|y|y2|z}tics add.
Examples:192

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set xtics 0, 5, 10
set xtics add (7.5)
set mxtics 5

Major tics at 0,5,7.5,10, minor tics at 1,2,3,4,6,7,8,9
set logscale y
set ytics format ""set ytics 1e-6, 10, 1
set ytics add ("1" 1, ".1" 0.1, ".01" 0.01, "10^-3" 0.001, \"10^-4" 0.0001)
set mytics 10

Major tics with special formatting, minor tics at log positions
By default, minor tics are off for linear axes and on for logarithmic axes. They inherit the settings foraxis|border and {no}mirror specified for the major tics. Please see set xtics (p. 235) for information
about these.
Mxtics time
Syntax:set mxtics time <N> {seconds|minutes|hours|days|weeks|months|years}

This is a new command option introduced in gnuplot version 6. It places minor tic marks exactly at some
integral number of time units rather than at some fraction of the major tic interval.
The new default is that minor tics are not generated if the major tics are in time mode (set xdata time orset xtics time).
set mxtics or set mxtics <freq> can restore the pre-version 6 behavior but this was always problematic.
For example, automatic subdivision of a 72-year span placed major tics at 12-year intervals and minor tics
at 5-year intervals.
Using set mxtics time 2 years, however, will place a minor tic mark exactly at the start of alternate years.
set mxtics time 1 month will place tic marks exactly at 1 Jan, 1 Feb, 1 Mar, 1 Apr, ... even though thoseintervals contain an unequal number of days.

My2tics
Minor tic marks along the y2 (right-hand) axis are controlled by set my2tics. Please see set mxtics(p. 191).

MyticsMinor tic marks along the y axis are controlled by set mytics. Please see set mxtics (p. 191).

MzticsMinor tic marks along the z axis are controlled by set mztics. Please see set mxtics (p. 191).

Nonlinear
Syntax:set nonlinear <axis> via f(axis) inverse g(axis)
unset nonlinear <axis>

gnuplot 6.0

193This command is similar to the set link command except that only one of the two linked axes is visible.
The hidden axis remains linear. Coordinates along the visible axis are mapped by applying g(x) to hidden
axis coordinates. f(x) maps the visible axis coordinates back onto the hidden linear axis. You must provide
both the forward and inverse expressions.
To illustrate how this works, consider the case of a log-scale x2 axis.
set x2ange [1:1000]
set nonlinear x2 via log10(x) inverse 10**x

This achieves the same effect as set log x2. The hidden axis in this case has range [0:3], obtained by
calculating [log10(xmin):log10(xmax)].
The transformation functions f() and g() must be defined using a dummy variable appropriate to the nonlinear
axis:
axis: x x2
axis: y y2
axis: z cb
axis: rdummy variable x
dummy variable y
dummy variable z
dummy variable r

Example:set xrange [-3:3]
set nonlinear x via norm(x) inverse invnorm(x)This example establishes a probability-scaled ("probit") x axis, such that plotting the cumulative normal
function Phi(x) produces a straight line plot against a linear y axis.
Example:logit(p) = log(p/(1-p))logistic(a) = 1. / (1. + exp(-a))
set xrange [.001 : .999]
set nonlinear y via logit(y) inverse logistic(y)plot logit(x)This example establishes a logit-scaled y axis such that plotting logit(x) on a linear x axis produces a straightline plot.
Example:f(x) = (x <= 100) ? x : (x < 500) ? NaN : x-390
g(x) = (x <= 100) ? x : x+390
set xrange [0:1000] noextend
set nonlinear x via f(x) inverse g(x)set xtics add (100,500)
plot sample [x=1:100] x, [x=500:1000] x

This example creates a "broken axis". X coordinates 0-100 are at the left, X coordinates 500-1000 are at
the right, there is a small gap (10 units) between them. So long as no data points with (100 < x < 500) areplotted, this works as expected.

ObjectThe set object command defines a single object which will appear in subsequent plots. You may define as
many objects as you like. Currently the supported object types are rectangle, circle, ellipse, and polygon.
Rectangles inherit a default set of style properties (fill, color, border) from those set by the command set
style rectangle. Every object can be given individual style properties when it is defined or in a latercommand.
Objects to be drawn in 2D plots may be defined in any combination of axis, graph, polar, or screen coordinates. Object specifications in 3D plots cannot use graph coordinates. Rectangles and ellipses in 3D plots
are limited to screen coordinates.
Syntax:

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set object <index><object-type> <object-properties>{front|back|behind|depthorder}{clip|noclip}{fc|fillcolor <colorspec>} {fs <fillstyle>}{default} {lw|linewidth <width>} {dt|dashtype <dashtype>}
unset object <index><object-type> is either rectangle, ellipse, circle, or polygon. Each object type has its own set ofcharacteristic properties.
The options front, back, behind control whether the object is drawn before or after the plot itself. Seelayers (p. 60). Setting front will draw the object in front of all plot elements, but behind any labels thatare also marked front. Setting back will place the object behind all plot curves and labels. Setting behind
will place the object behind everything including the axes and back rectangles, thus
set object rectangle from screen 0,0 to screen 1,1 behind

can be used to provide a colored background for the entire graph or page.
By default, objects are clipped to the graph boundary unless one or more vertices are given in screen
coordinates. Setting noclip will disable clipping to the graph boundary, but will still clip against the screen
size.
The fill color of the object is taken from the <colorspec>. fillcolor may be abbreviated fc. The fill styleis taken from <fillstyle>. See colorspec (p. 57) and fillstyle (p. 217). If the keyword default is given,
these properties are inherited from the default settings at the time a plot is drawn. See set style rectangle(p. 220).

Rectangle
Syntax:set object <index> rectangle{from <position> {to|rto} <position> |center <position> size <w>,<h> |at <position> size <w>,<h>}The position of the rectangle may be specified by giving the position of two diagonal corners (bottom left
and top right) or by giving the position of the center followed by the width and the height. In either casethe positions may be given in axis, graph, or screen coordinates. See coordinates (p. 33). The options atand center are synonyms.
Examples:# Force the entire area enclosed by the axes to have background color cyan
set object 1 rect from graph 0, graph 0 to graph 1, graph 1 backset object 1 rect fc rgb "cyan" fillstyle solid 1.0# Position a red square with lower left at 0,0 and upper right at 2,3
set object 2 rect from 0,0 to 2,3 fc lt 1
# Position an empty rectangle (no fill) with a blue border
set object 3 rect from 0,0 to 2,3 fs empty border rgb "blue"# Return fill and color to the default style but leave vertices unchanged
set object 2 rect default

Rectangle corners specified in screen coordinates may extend beyond the edge of the current graph. Otherwise
the rectangle is clipped to fit in the graph.

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195

Ellipse
Syntax:set object <index> ellipse {at|center} <position> size <w>,<h>{angle <orientation>} {units xy|xx|yy}{<other-object-properties>}

The position of the ellipse is specified by giving the center followed by the width and the height (actually
the major and minor axes). The keywords at and center are synonyms. The center position may be given
in axis, graph, or screen coordinates. See coordinates (p. 33). The major and minor axis lengths mustbe given in axis coordinates. The orientation of the ellipse is specified by the angle between the horizontal
axis and the major diameter of the ellipse. If no angle is given, the default ellipse orientation will be usedinstead (see set style ellipse (p. 220)). The units keyword controls the scaling of the axes of the ellipse.
units xy means that the major axis is interpreted in terms of units along the x axis, while the minor axis inthat of the y axis. units xx means that both axes of the ellipses are scaled in the units of the x axis, while
units yy means that both axes are in units of the y axis. The default is xy or whatever set style ellipse
units was set to.
NB: If the x and y axis scales are not equal, (e.g. units xy is in effect) then the major/minor axis ratio will
no longer be correct after rotation.
Note that set object ellipse size <2r>,<2r> does not in general produce the same result as set object
circle <r>. The circle radius is always interpreted in terms of units along the x axis, and will always
produce a circle even if the x and y axis scales are different and even if the aspect ratio of your plot is not
1. If units is set to xy, then ’set object ellipse’ interprets the first <2r> in terms of x axis units and thesecond <2r> in terms of y axis units. This will only produce a circle if the x and y axis scales are identicaland the plot aspect ratio is 1. On the other hand, if units is set to xx or yy, then the diameters specified
in the ’set object’ command will be interpreted in the same units, so the ellipse will have the correct aspectratio, and it will maintain its aspect ratio even if the plot is resized.
CircleSyntax:set object <index> circle {at|center} <position> size <radius>{arc [<begin>:<end>]} {no{wedge}}{<other-object-properties>}

The position of the circle is specified by giving the position of the center center followed by the radius. The
keywords at and center are synonyms. In 2D plots the position and radius may be given in any coordinate
system. See coordinates (p. 33). Circles in 3D plots cannot use graph coordinates. In all cases theradius is calculated relative to the horizontal scale of the axis, graph, or canvas. Any disparity between thehorizontal and vertical scaling will be corrected for so that the result is always a circle. If you want to draw
a circle in plot coordinates (such that it will appear as an ellipse if the horizontal and vertical scales aredifferent), use set object ellipse instead.
By default a full circle is drawn. The optional qualifier arc specifies a starting angle and ending angle, indegrees, for one arc of the circle. The arc is always drawn counterclockwise.
See also set style circle (p. 220), set object ellipse (p. 195).
Polygon
Syntax:set object <index> polygon
from <position> to <position> ... {to <position>}orfrom <position> rto <position> ... {rto <position>}

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The position of the polygon may be specified by giving the position of a sequence of vertices. These may be
given in any coordinate system. If relative coordinates are used (rto) then the coordinate type must matchthat of the previous vertex. See coordinates (p. 33).
Example:set object 1 polygon from 0,0 to 1,1 to 2,0
set object 1 fc rgb "cyan" fillstyle solid 1.0 border lt -1

Depthorder The option set object N depthorder applies to 3D polygon objects only. Rather thanassigning the object to layer front/back/behind it is included in the list of pm3d quadrangles sorted andrendered in order of depth by set pm3d depthorder. As with pm3d surfaces, two-sided coloring can begenerated by specifying the object fillcolor as a linestyle. In this case the ordering of the first three vertices
in the polygon determines the "side".
If you set this property for an object that is not a 3D polygon it probably will not be drawn at all.

Offsets
Autoscaling sets the x and y axis ranges to match the coordinates of the data that is plotted. Offsets
provide a mechanism to expand these ranges to leave empty space between the data and the plot borders.
Autoscaling then further extends each range to reach the next axis tic unless this has been suppressed by
set autoscale noextend or set xrange noextend. See noextend (p. 152). Offsets affect only scaling
for the x1 and y1 axes.
Syntax:set offsets <left>, <right>, <top>, <bottom>
unset offsets
show offsets

Each offset may be a constant or an expression. Each defaults to 0. By default, the left and right offsets
are given in units of the first x axis, the top and bottom offsets in units of the first y axis. Alternatively,
you may specify the offsets as a fraction of the total graph dimension by using the keyword "graph". Only
"graph" offsets are possible for nonlinear axes.
A positive offset expands the axis range in the specified direction, e.g. a positive bottom offset makes ymin
more negative. Negative offsets interact badly with autoscaling and clipping.
Example:set autoscale noextend
set offsets graph 0.05, 0, 2, 2
plot sin(x)This graph of sin(x) will have y range [-3:3] because the function will be autoscaled to [-1:1] and the verticaloffsets add 2 at each end of the range. The x range will be [-11:10] because the default is [-10:10] and it has
been expanded to the left by 0.05 of that total range.

OriginThe set origin command is used to specify the origin of a plotting surface (i.e., the graph and its margins)on the screen. The coordinates are given in the screen coordinate system (see coordinates (p. 33) for
information about this system).
Syntax:set origin <x-origin>,<y-origin>gnuplot 6.0

197

OutputSyntax:set output {"<filename>"}unset output
show output

Graphs produced by non-interactive terminals are by default sent to stdout. The set output command
redirects output to the specified file or device. The file opened by this command remains open until asubsequent set/unset output command, a change in terminal type, or exit from gnuplot.
Interactive terminals ignore set output.
The filename must be enclosed in quotes. If the filename is omitted, the command is equivalent to unset
output; any output file opened by a previous set output will be closed and new output will be sent tostdout.
When both set terminal and set output are used together, it is safest to give set terminal first, becausesome terminals set a flag which is needed in some operating systems. This would be the case, for example,
if the operating system needs a separate open command for binary files.
On platforms that support pipes, it may be useful to pipe terminal output. For instance,
set output "|lpr -Plaser filename"set term png; set output "|display png:-"

On MSDOS machines, set output "PRN" directs output to the default printer.

Overflow
Syntax:set overflow {float | NaN | undefined}
unset overflow

This version of gnuplot supports 64-bit integer arithmetic. This means that for values from 2^53 to 2^63
(roughly 10^16 to 10^19) integer evaluation preserves more precision than evaluation using IEEE 754 floating
point arithmetic. However unlike the IEEE floating point representation, which sacrifices precision to span atotal range of roughly [-10^307 : 10^307], integer operations that result in values outside the range [-2^63 :
2^63] overflow. The set overflow command lets you control what happens in case of overflow. See options
below.
set overflow is the same as set overflow float. It causes the result to be returned as a real number rather
than as an integer. This is the default.
The command unset overflow causes integer arithmetic overflow to be ignored. No error is shown. Thismay be desirable if your platform allows only 32-bit integer arithmetic and you want to approximate thebehaviour of gnuplot versions prior to 5.4.
The reset command does not affect the state of overflow handling.
Earlier gnuplot versions were limited to 32-bit arithmetic and ignored integer overflow. Note, however, thatsome built-in operators did not use integer arithmetic at all, even when given integer arguments. This
included the exponentiation operator N**M and the summation operator (see summation (p. 51)). These
operations now return an integer value when given integer arguments, making them potentially susceptible
to overflow and thus affected by the state of set overflow.
Float
If an integer arithmetic expression overflows the limiting range, [-2^63 : 2^63] for 64-bit integers, the result
is returned as a floating point value instead. This is not treated as an error. Example:
gnuplot> set overflow float
gnuplot> A = 2**62 - 1; print A, A+A, A+A+A
4611686018427387903 9223372036854775806 1.38350580552822e+19

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NaN
If an integer arithmetic expression overflows the limiting range, [-2^63 : 2^63] for 64-bit integers, the result
is returned as NaN (Not a Number). This is not treated as an error. Example:
gnuplot> set overflow NaN
gnuplot> print 10**18, 10**19
1000000000000000000 NaN

Undefined
If an integer arithmetic expression overflows the limiting range, [-2^63 : 2^63] for 64-bit integers, the result
is undefined. This is treated as an error. Example:
gnuplot> set overflow undefined
gnuplot> A = 10**19^
undefined value

Affected operations
The set overflow state affects the arithmetic operators+ - * / **and the built-in summation operation sum.
All of these operations will return an integer result if all of the arguments are integers, so long as no overflow
occurs during evaluation.
The set overflow state does not affect logical or bit operations
<< >>

| ^ &

If overflow occurs at any point during the course of evaluating of a summation set overflow float will cause
the result to be returned as a real number even if the final sum is within the range of integer representation.

PaletteThe palette is a set of colors, usually ordered as one or more stepped gradients, used to color pm3d surfaces,
heat maps, and other plot elements. Colors in the current palette are automatically mapped from plot
coordinate z values or from an extra data column of gray values. The current palette is shown by default
in a separate colorbox drawn next to plots that use plot style pm3d. The colorbox can be customized or
disabled. See set colorbox (p. 159). See also show palette (p. 244) and test palette (p. 253).
Syntax:set paletteset palette {{ gray | color }{ gamma <gamma> }{rgbformulae <r>,<g>,<b>| defined { ( <gray1> <color1> {, <grayN> <colorN>}... ) }| file '<filename>' {datafile-modifiers}| colormap <colormap-name>| functions <R>,<G>,<B>}{ cubehelix {start <val>} {cycles <val>} {saturation <val>} }{ viridis }{ model { RGB | CMY | HSV {start <radians>} } }{ positive | negative }{ nops_allcF | ps_allcF }{ maxcolors <maxcolors> }}A palette can be defined in several ways.

gnuplot 6.0

199- Provide formulae for the red, green, and blue composet palette rgbformulae 7,5,15 (this is the default)
nents as a function of the gray value between 0 and 1.
Set palette rgbformulae allows you to choose fromset palette defined (0 "white", 1 "dark-red")
36 predefined formulae. Set palette functions allows
you to define your own functions.
- Use set palette defined to specify one or more
set palette cubehelix
smooth gradients, each spanning one segment of the total z range.
- Load a previously save palette into the current palette.
set palette viridis
Set palette file reads a saved palette from a file. Set
palette colormap extracts the RGB components froma saved colormap.
- Specify a named palette, perhaps with additional parameters to customize. The named palettes currently
provided are cubehelix (a customizable family of palettes) and viridis.
set palette (without options) restores the default values.
set palette negative inverts the direction of the palette, e.g. set palette viridis negative creates a
gradient from yellow to blue rather than from blue to yellow.
set palette gray switches to a grayscale palette. set palette color restores the most recent color palette.
In pm3d color surfaces the gray value of each small quadrangle is obtained by mapping the averaged zcoordinate of its 4 corners from the range [min z,max z] into the range of grays, which is always [0:1]. The
palette maps that gray value into an RGB color.
Palette colors can be mentioned explicitly in a color specification (see colorspec (p. 57)). This is useful toassign a palette color to an object or label.
The palette can be defined in any of three color spaces: RGB CMY HSV. See set palette model (p. 202).
All color component values in all color spaces are limited to [0,1].
Rgbformulae
set palette rgbformulae <function 1>, <function 2>, <function 3>

Despite its name, this option applies to all color spaces. You must specify one of 36 preset mapping functions
by number for each color component. The available functions are listed by show palette rgbformulae. The
default is set palette rgbformulae 7,5,15. In RGB space this uses function 7 to map the red component,
function 5 to map the green component, and function 15 to map the blue component. A negative function
number inverts the sense of that component by mapping f(1-gray) rather than f(gray).
Some nice schemes in RGB color space
7,5,15... default (black-blue-red-yellow)
3,11,6... green-red-violet
23,28,3 ... ocean (green-blue-white)
21,22,23 ... hot (black-red-yellow-white)
30,31,32 ... black-blue-violet-yellow-white
33,13,10 ... rainbow (blue-green-yellow-red)
34,35,36 ... AFM hot (black-red-yellow-white)ocean

rainbow

AFM hot

A full color palette in HSV color space
3,2,2... red-yellow-green-cyan-blue-magenta-red

set palette model HSV rgbformulae 3,2,2

DefinedGray-to-rgb mapping can be manually set by use of palette defined: A color gradient is defined and used
to give the rgb values. Such a gradient is a piecewise linear mapping from gray values in [0,1] to the RGB
space [0,1]x[0,1]x[0,1]. You must specify the gray values and the corresponding RGB values between which
linear interpolation will be done.
Syntax:

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set palettedefined { ( <gray1> <color1> {, <grayN> <colorN>}... ) }where N ≥ 2 and <grayN> are gray values which are mapped to [0,1]. The corresponding rgb color <colorN>
can be specified in three different ways:<color> :={ <r> <g> <b> | '<color-name>' | '#rrggbb' }Either by three numbers (each in [0,1]) for red, green and blue, separated by whitespace, or the name of thecolor in quotes or X style color specifiers also in quotes. You may freely mix the three types in a gradientdefinition, but the named color "red" will be something strange if RGB is not selected as color space. Useshow colornames for a list of known color names.
The <gray> values must form an ascending sequence of real numbers; the sequence will be automaticallyrescaled to [0,1].
set palette defined (without a gradient definition in braces) switches to RGB color space and uses a presetfull-spectrum color gradient. Use show palette gradient to display the gradient.
Examples:To produce a gray palette (useless but instructive) use:set palette model RGB
set palette defined ( 0 "black", 1 "white" )To produce a blue-to-yellow-to-red palette use (all equivalent):
set palette defined ( 0 "blue", 1 "yellow", 2 "red" )set palette defined ( 0 0 0 1, 1 1 1 0, 2 1 0 0 )set palette defined ( 0 "#0000ff", 1 "#ffff00", 2 "#ff0000" )Full color spectrum within HSV color space:set palette model HSV
set palette defined ( 0 0 1 1, 1 1 1 1 )set palette defined ( 0 0 1 0, 1 0 1 1, 6 0.8333 1 1, 7 0.8333 0 1)

Full color HSV spectrum wrapping at some hue other than red
set palette model HSV start 0.15
set palette defined ( 0 0 1 1, 1 1 1 1 )To produce a palette with only a few, equally-spaced colors:
set palette model RGB maxcolors 4
set palette defined ( 0 "yellow", 1 "red" )’Traffic light’ palette (non-smooth color jumps at gray = 1/3 and 2/3).
set palette model RGB
set palette defined (0 "dark-green", 1 "green", \1 "yellow",
2 "dark-yellow", \2 "red",3 "dark-red" )Functionsset palette functions <f1(gray)>, <f2(gray)>, <f3(gray)>This option is like set palette rgbformulae except that you must provide an actual function for each color
component rather than the index of a preset function. The dummy parameter of each function, if any, mustbe "gray". The function must map gray values in [0,1] to output values also in [0,1].
Examples:To produce a full color palette use:set palette model HSV functions gray, 1, 1

A nice black to gold palette:
set palette model RGB functions 1.1*gray**0.25, gray**0.75, 0

A gamma-corrected black and white palette
gamma = 2.2
map(gray) = gray**(1./gamma)set palette model RGB functions map(gray), map(gray), map(gray)gnuplot 6.0

201

Gray
set palette gray switches to a grayscale palette shading from 0.0 = black to 1.0 = white. set palettecolor is an easy way to switch back from the gray palette to the last color mapping.
Cubehelix
The "cubehelix" option defines a family of palettes in which color (hue) varies around the standard color
wheel while the net perceived intensity increases monotonically as the gray value goes from 0 to 1.
D A Green (2011) http://arxiv.org/abs/1108.5083

start defines the starting point along the color wheel in radians. cycles defines how many color wheel cycles
span the palette range. Larger values of saturation produce more saturated color; saturation > 1 may leadto clipping of the individual RGB components and to intensity becoming non-monotonic. The palette is also
affected by set palette gamma. The default values are
set palette cubehelix start 0.5 cycles -1.5 saturation 1
set palette gamma 1.5

Viridisset palette viridis

The "viridis" palette is a (blue->yellow) gradient designed to accommodate users with impaired color vision.
Viridis was developed by Stéfan van der Walt and Nathaniel Smith. It features an approximately linear
gradient of perceived brightness (luminance). The colormap version used in gnuplot is based on"Viridis - Colorblind-Friendly Color Maps for R", Garnier et al (2021)
https://CRAN.R-project.org/package=viridis

Colormap
set palette colormap <name> loads a defined gradient that was previously saved to a colormap. Alphachannel information in the colormap, if any, will be lost when the color values are copied into the palettedefinition. See colormap (p. 155).
File
set palette file is basically a set palette defined (<gradient>) where <gradient> is read from a datafile
or datablock. The color values may be provided either as a single 24-bit packed RGB integer (1 or 2 using
columns) or as three separate fractional R, G, B components (3 or 4 using columns). If no explicit grayvalue is provided in the first input column, the line number is used; this generates equal spacing along thecolor axis.
The file is read as a normal data file, so all datafile modifiers can be used. Please note that R might actuallybe H if HSV color space is selected.
Use show palette gradient to display the gradient.
Examples:Read in a palette of RGB triples each in range [0,255]:
set palette file 'some-palette' using ($1/255):($2/255):($3/255)

Equidistant rainbow (blue-green-yellow-red) palette:
set palette model RGB file "-" using 1:2:3
0 0 1
0 1 0
1 1 0
1 0 0
e

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Same thing using explicit gray intervals and packed RGB values:
set palette model RGB file "-" using 1:2
1 0x0000ff
2 0x00ff00
3 0xffff00
4 0xff0000
e

Binary palette files are supported as well, see binary general (p. 121). Example: put 64 triplets of R,G,B
doubles into file palette.bin and load it by
set palette file "palette.bin" binary record=64 using 1:2:3

Gamma correction
Automatic gamma correction via set palette gamma <gamma> can be done for gray maps (set palettegray) and for the cubehelix color palette schemes. Gamma = 1 produces a linear ramp of intensity. See
test palette (p. 253).
For gray mappings, <gamma> defaults to 1.5 which is usually suitable.
The gamma correction is applied to the cubehelix color palette family, but not to other palette coloring
schemes. However, you may easily implement gamma correction for explicit color functions.
Example:set palette model RGB
set palette functions gray**0.64, gray**0.67, gray**0.70

To use gamma correction with interpolated gradients specify intermediate gray values with appropriate
colors. Instead ofset palette defined ( 0 0 0 0, 1 1 1 1 )use e.g.
set palette defined ( 0 0 0 0, 0.5 .73 .73 .73, 1 1 1 1 )or even more intermediate points until the linear interpolation fits the "gamma corrected" interpolation wellenough.
Maxcolors
set palette maxcolors <N> limits the palette to N discrete colors selected from a continuous palettesampled at equally spaced intervals. If you want unequal spacing of N discrete colors, use set palettedefined instead of a single continuous palette.
The primary use for this is to generate heat maps with discrete colors, each representing a range of values.
A second use is to handle terminals that support only a limited number of colors (e.g. 256 colors in gif orsixel). The default gnuplot linetype colors use up some of these, further limiting the number available forpalette use. Thus a multiplot using multiple palettes could fail because the first palette has used all theavailable color positions. You can mitigate this by restricting the number of colors used by each palette.
Color modelset palette model { RGB | CMY | HSV {start <radians>} }Sometimes RGB color space is not the most convenient color space to work in. You may change the color
space model to one of RGB, HSV, CMY. RGB stands for Red, Green, Blue; CMY stands for Cyan,
Magenta, Yellow; HSV stands for Hue, Saturation, Value. In HSV space the full color wheel is traversed as
H runs from 0 to 1, so H=0 and H=1 describe the same color. By default the cycle starts and ends at red.
The optional parameter start introduces an offset, so after set palette model HSV start 0.3 H=0 and
H=1 both correspond to green.

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For more information on color models see: http://en.wikipedia.org/wiki/Color space
Documentation for palette options was written for RGB color space, so please note that R really means"first color component", which can be H or C depending on the actual color space in use.
Postscript
This section is only relevant to output from set term postscript color. When the palette is defined using
set palette rgbformulae, gnuplot writes a postscript implementation of the required analytical formulae
as a header just before a pm3d drawing (see /g and /cF definitions). Usually, it makes sense to write
definitions of only the 3 formulae used in the palette. This is the default option nops allcF. The option
ps allcF instead writes definitions of all 36 formulae. This allows you to edit the postscript file in order tohave different palettes for different surfaces in one graph.
If you write a pm3d surface to a postscript file, it may be possible to reduce the file size by running the awk
script pm3dCompress.awk afterward. If the data lies on a rectangular grid, even greater compression may
be possible using the awk script pm3dConvertToImage.awk. Both scripts are distributed with gnuplot.
Usage:
awk -f pm3dCompress.awk thefile.ps >smallerfile.ps
awk -f pm3dConvertToImage.awk thefile.ps >smallerfile.ps

Parametric
The set parametric command changes the meaning of plot (splot) from normal functions to parametricfunctions. The command unset parametric restores the plotting style to normal, single-valued expression
plotting.
Syntax:set parametricunset parametricshow parametric

For 2D plotting, a parametric function is determined by a pair of parametric functions operating on aparameter. An example of a 2D parametric function would be plot sin(t),cos(t), which draws a circle (ifthe aspect ratio is set correctly — see set size (p. 213)). gnuplot will display an error message if both
functions are not provided for a parametric plot.
For 3D plotting, the surface is described as x=f(u,v), y=g(u,v), z=h(u,v). Therefore a triplet of functions isrequired. An example of a 3D parametric function would be cos(u)*cos(v),cos(u)*sin(v),sin(u), whichdraws a sphere. gnuplot will display an error message if all three functions are not provided for a parametric
splot.
The total set of possible plots is a superset of the simple f(x) style plots, since the two functions can describe
the x and y values to be computed separately. In fact, plots of the type t,f(t) are equivalent to those producedwith f(x) because the x values are computed using the identity function. Similarly, 3D plots of the typeu,v,f(u,v) are equivalent to f(x,y).
Note that the order the parametric functions are specified is xfunction, yfunction (and zfunction) and thateach operates over the common parametric domain.
Also, the set parametric function implies a new range of values. Whereas the normal f(x) and f(x,y) styleplotting assume an xrange and yrange (and zrange), the parametric mode additionally specifies a trange,
urange, and vrange. These ranges may be set directly with set trange, set urange, and set vrange, orby specifying the range on the plot or splot commands. Currently the default range for these parametricvariables is [-5:5]. Setting the ranges to something more meaningful is expected.

Paxis
Syntax:

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set paxis <axisno> {range <range-options> | tics <tic-options>}
set paxis <axisno> label <label-options> { offset <radial-offset> }show paxis <axisno> {range | tics}

The set paxis command is equivalent to the set xrange and set xtics commands except that it acts on
one of the axes p1, p2, ... used in parallel axis plots and spiderplots. See parallelaxes (p. 89), set xrange(p. 233), and set xtics (p. 235). The normal options to the range and tics commands are accepted
although not all options make sense for parallel axis plots.
set paxis <axisno> label <label-options> is relevant to spiderplots but ignored otherwise. Axes of aparallel axis plot can be labeled using the title option of the plot command, which generates an xtic label.
Note that this may require also set xtics.
The axis linetype properties are controlled using set style parallelaxis (p. 221).

PixmapSyntax:set pixmap <index> {"filename" | colormap <name>}at <position>{width <w> | height <h> | size <w>,<h>}{front|back|behind} {center}show pixmaps
unset pixmaps
unset pixmap <index>

The set pixmap command is similar to set object in that it defines an object that will appear on subsequentplots. The rectangular array of red/green/blue/alpha values making up the pixmap are read from a png,
jpeg, or gif file. The position and extent occupied by the pixmap in the gnuplot output may be specified inany coordinate system (see coordinates (p. 33)). The coordinates given by at <position> refer to thelower left corner of the pixmap unless keyword center is present.
If the x-extent of the rendered pixmap is set using width <x-extent> the aspect ratio of the original
image is retained and neither the aspect ratio nor the orientation of the pixmap changes with axis scaling or
rotation. Similarly if the y-extent is set using height <y-extent>. If both the x-extent and y-extent are
given using size <x-extent> <y-extent> this overrides the original aspect ratio. If no size is set then theoriginal size in pixels is used (the effective size is then terminal-dependent).
Pixmaps are not clipped to the border of the plot. As an exception to the general behaviour of objects andlayers, a pixmap assigned to layer behind is rendered for only the first plot in a multiplot. This allows all
panels in a multiplot to share a single background pixmap.
Examples:# Use a gradient as the background for all plotting# Both x and y will be resized to fill the entire canvas
set pixmap 1 "gradient.png"
set pixmap 1 at screen 0, 0 size screen 1, 1 behind# Place a logo at the lower right of each page plotted
set pixmap 2 "logo.jpg"
set pixmap 2 at screen 0.95, 0 width screen 0.05 behind# Place a small image at some 3D coordinate# It will move as if attached to the surface being plotted# but will always face forward and remain uprightset pixmap 3 "image.png" at my_x, my_y, f(my_x,my_y) width screen .05
splot f(x,y)

Pixmap from colormap
Syntax:set pixmap <index> colormap <name>gnuplot 6.0
Another use of pixmaps is to store a gradient describedby a named palette. This is an easy way to specify gradient fill for a rectangular area. It could be used to draw
a separate colorbox for that named palette, or even as a
background for the entire plot or the entire canvas.
set palette defined (0 "beige", 1 "light-cyan")
set colormap new Gradientset pixmap 1 colormap Gradient behind
set pixmap 1 at screen 0,0 size screen 1,1
plot <something>

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Pm3d
pm3d is an splot style for drawing palette-mapped 3d and 4d data as color/gray maps and surfaces. It
allows plotting gridded or non-gridded data without preprocessing. pm3d style options also affect solid-fillpolygons used to construct other 3D plot elements.
Syntax (the options can be given in any order):set pm3d {{ at <position> }{ interpolate <steps/points in scan, between scans> }{ scansautomatic | scansforward | scansbackward| depthorder {base} }{ flush { begin | center | end } }{ ftriangles | noftriangles }{ clip | clip1in | clip4in }{ {no}clipcb }{ corners2color{ mean|geomean|harmean|rms|median|min|max|c1|c2|c3|c4 }}{ {no}lighting{primary <fraction>} {specular <fraction>} {spec2 <fraction>}}{ {no}border {retrace} {<linestyle-options>}}{ implicit | explicit }{ map }}
show pm3d
unset pm3d

Note that pm3d plots are plotted sequentially in the order given in the splot command. Thus earlier plots
may be obscured by later plots. To avoid this you can use the depthorder scan option.
The pm3d surfaces can be projected onto the top or bottom of the view box. See pm3d position (p. 207).
The following command draws three color surfaces at different altitudes:
set border 4095
set pm3d at s
splot 10*x with pm3d at b, x*x-y*y, x*x+y*y with pm3d at t

See also help for set palette (p. 198), set cbrange (p. 243), set colorbox (p. 159), and the demo filedemo/pm3d.dem.
With pm3d (pm3d explicit)
Syntaxsplot DATA using (x):(y):(z){:(color)} with pm3d
{fs|fillstyle <fillstyle>} {fc|fillcolor <colorspec>}{zclip [zmin:zmax]}

The rendering properties of all pm3d surfaces are controlled using set pm3d (p. 205). By default the fullsurface is rendered as a grid of quadrangles, each colored by the palette color mapped to that z coordinate.

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If you provide a fourth input column, the palette mapping uses that value rather than z. See pm3d fillcolor(p. 209), pm3d color assignment (p. 208).
When you explicitly use with pm3d in the plot command rather than using another plot style while set
pm3 implicit is active, additional rendering options are possible. This allows you to use separate coloring
schemes for different surfaces in the same plot.
EXPERIMENTAL: This gnuplot version introduces an option zclip that clips the generated surface smoothly
at a pair of limiting z values. The example below animates gradual removal of the top portion of a two-color
3D surface.
set style line 101 lc "gray"set style line 102 lc "blue"
set pm3d depthorder
do for [i=0:N] {splot f(x,y) with pm3d fillcolor ls 101 zclip [* : zmax-(i*delta)]
pause 0.2 # 1/5 second between animation frames}

Pm3d implicit
A pm3d color surface is drawn if the splot command explicitly specifies with pm3d, if the data or function
style is set to pm3d globally, or if the pm3d mode is set pm3d implicit. For the latter two cases the pm3d
surface is draw in addition to the mesh produced by the style specified in the plot command. E.g.
splot 'fred.dat' with lines, 'lola.dat' with lines

would draw both a mesh of lines and a pm3d surface for each data set. If the option explicit is on (orimplicit is off) only plots specified by the with pm3d attribute are plotted with a pm3d surface, e.g.:
splot 'fred.dat' with lines, 'lola.dat' with pm3d

would plot ’fred.dat’ with lines (only) and ’lola.dat’ with a pm3d surface.
On gnuplot start-up, the mode is explicit. For historical and compatibility reasons, the commands set
pm3d; (i.e. no options) and set pm3d at X ... (i.e. at is the first option) change the mode to implicit.
The command set pm3d; sets other options to their default state.
If you set the default data or function style to pm3d, e.g.:
set style data pm3d

then the options implicit and explicit have no effect.
Algorithm
Let us first describe how a map/surface is drawn. The input data come from an evaluated function or froman splot data file. Each surface consists of a sequence of separate scans (isolines). The pm3d algorithm
fills the region between two neighbouring points in one scan with another two points in the next scan by
a gray (or color) according to z-values (or according to an additional ’color’ column, see help for using(p. 135)) of these 4 corners; by default the 4 corner values are averaged, but this can be changed by the
option corners2color. In order to get a reasonable surface, the neighbouring scans should not cross andthe number of points in the neighbouring scans should not differ too much; of course, the best plot is withscans having same number of points. There are no other requirements (e.g. the data need not be gridded).
Another advantage is that the pm3d algorithm does not draw anything outside of the input (measured or
calculated) region.
Surface coloring works with the following input data:
1. splot of function or of data file with one or three data columns: The gray/color scale is obtained by
mapping the averaged (or corners2color) z-coordinate of the four corners of the above-specified quadrangle
into the range [min color z,max color z] of zrange or cbrange providing a gray value in the range [0:1].

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207This value can be used directly as the gray for gray maps. The normalized gray value can be further mapped
into a color — see set palette (p. 198) for the complete description.
2. splot of data file with two or four data columns: The gray/color value is obtained by using the last-column
coordinate instead of the z-value, thus allowing the color and the z-coordinate be mutually independent. Thiscan be used for 4d data drawing.
Other notes:
1. The term ’scan’ referenced above is used more among physicists than the term ’iso curve’ referenced ingnuplot documentation and sources. You measure maps recorded one scan after another scan, that’s why.
2. The ’gray’ or ’color’ scale is a linear mapping of a continuous variable onto a smoothly varying palette ofcolors. The mapping is shown in a rectangle next to the main plot. This documentation refers to this as a"colorbox", and refers to the indexing variable as lying on the colorbox axis. See set colorbox (p. 159),
set cbrange (p. 243).
Lighting
Syntax:set pm3d lighting {primary <frac>} {specular <frac>} {spec2 <frac>}
set pm3d spotlight {rgb <color>} {rot_x <angle>} {rot_z <angle>}{Phong <value>} {default}

By default the colors assigned to pm3d objects are not dependent on orientation or viewing angle. This statecorresponds to set pm3d nolighting. The command set pm3d lighting selects a simple lighting model
consisting of a single fixed source of illumination contributing 50% of the overall lighting. The strength of
this light relative to the ambient illumination can be adjusted by set pm3d lighting primary <fraction>.
Inclusion of specular highlighting can be adjusted by setting a fractional contribution:
set pm3d lighting primary 0.50 specular 0.0
set pm3d lighting primary 0.50 specular 0.6# no highlights# strong highlights

Solid-color pm3d surfaces tend to look very flat without specular highlights.
Since highlights the primary source only affect one side of the surface, it may help to add illumination froma second spotlight shining from another direction. The strength of this second spotlight is set by "spec2<fraction>". The second spotlight is included in the lighting model only if spec2 is greater than zero.
The direction, color, and specular model is controlled by "set pm3d spotlight". Use and positioning of thisspotlight is illustrated in the interactive demo spotlight.dem. See also hidden compare.dem (comparisonof hidden3d and pm3d treatment of solid-color surfaces)
Example:set pm3d lighting primary 0.8 spec 0.4 spec2 0.4
set pm3d spot rgb "blue"

Position
The pm3d colored surface can be drawn at the true z position of the surface or projected onto the base planeor the top plane. This is controlled by the at option with a string of up to 6 combinations of b, t and s. For
instance, at b plots at the bottom only, at st plots first at the surface and then on the top plane, while atbstbst is unlikely to be useful.
Colored quadrangles are plotted one after another. That means later quadrangles can occlude or overlap theprevious ones. You may try to switch between scansforward and scansbackward to force the first scanof the data to be plotted first or last. The default is scansautomatic where gnuplot makes a guess aboutscans order. The depthorder option completely reorders the quadrangles by sorting on the distance fromthe viewpoint. This allow to visualize even complicated surfaces; see pm3d depthorder (p. 208) for moredetails.

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Scanorder
set pm3d {scansautomatic | scansforward | scansbackward | depthorder}

By default the quadrangles making up a pm3d solid surface are rendered in the order they
are encountered along the surface grid points.
This order may be controlled by the optionsscansautomatic|scansforward|scansbackward. These scan options are not in general compatible withhidden-surface removal.
If two successive scans do not have same number of points, then it has to be decided whether to start taking
points for quadrangles from the beginning of both scans (flush begin), from their ends (flush end) or tocenter them (flush center). Note, that flush (center|end) are incompatible with scansautomatic: if you
specify flush center or flush end and scansautomatic is set, it is silently switched to scansforward.
If two subsequent scans do not have the same number of points, the option ftriangles specifies whether
color triangles are drawn at the scan tail(s) where there are not enough points in either of the scans. Thiscan be used to draw a smooth map boundary.
Gnuplot does not do true hidden surface removal for solid surfaces, but often it is sufficient to render thecomponent quadrangles in order from furthest to closest. This mode may be selected using the option
set pm3d depthorder

Note that the global option set hidden3d does not affect pm3d surfaces.
The depthorder option by itself tends to produce bad results when applied to the long thin rectangles
generated by splot with boxes. It works better to add the keyword base, which performs the depth sortusing the intersection of the box with the plane at z=0. This type of plot is further improved by adding alighting model. Example:
set pm3d depthorder baseset pm3d lighting
set boxdepth 0.4
splot $DATA using 1:2:3 with boxes

Clipping
Syntax:set pm3d {clip | clip1in | clip4in}
set pm3d {no}clipcb

The component quadrangles of a pm3d surface or other 3D object are by default smoothly clipped against
the current zrange. This is a change from earlier gnuplot versions. In 2D projection (set view map) thismode also clips against xrange and yrange.
Alternatively, surfaces can be clipped by rendering whole quadrangles but only those with all 4 corners
in-range on x, y, and z (set pm3d clip4in), or only those with at least one corner in-range on x, y, and z(set pm3d clip1in). The options clip, clip1in, and clip4in are mutually exclusive.
Separate from clipping based on spatial x, y, and z coordinates, quadrangles can be rendered or not basedon extreme palette color values. clipcb: (default) palette color values < cbmin are treated as cbmin; palettecolor values > cbmax are treated as cbmax. noclipcb: quadrangles with color value outside cbrange are
not drawn at all.
Color assignment
The default pm3d coloring assigns an individual color to each quadrangle of the surface grid. For alternative
coloring schemes that assign uniform color to the entire surface, see pm3d fillcolor (p. 209).
A single gray/color value (i.e. not a gradient) is assigned to each quadrangle. This value is calculated fromthe z-coordinates the four quadrangle corners according to corners2color <option>. The value is thenused to select a color from the current palette. See set palette (p. 198). It is not possible to change
palettes inside a single splot command.

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If a fourth column of data is provided, the coloring of individual quadrangles works as above except that thecolor value is distinct from the z value. As a separate coloring option, the fourth data column may provide
instead an RGB color. See rgbcolor variable (p. 59). In this case the plotting command must be
splot ... using 1:2:3:4 with pm3d lc rgb variable

Notice that ranges of z-values and color-values for surfaces are adjustable independently by set zrange, set
cbrange, set log z, set log cb, etc.
Corners2color
The color of each quadrangle in a pm3d surface is assigned based on the color values of its four bounding
vertices. The options ’mean’ (default), ’geomean’, ’harmean, ’rms’, and ’median’ produce various kinds ofsurface color smoothing, while options ’min’ and ’max’ choose minimal or maximal value, respectively. This
may not be desired for pixel images or for maps with sharp and intense peaks, in which case the options’c1’, ’c2’, ’c3’ or ’c4’ can be used instead to assign the quadrangle color based on the z-coordinate of only
one corner. Some experimentation may be needed to determine which corner corresponds to ’c1’, as theorientation depends on the drawing direction. Because the pm3d algorithm does not extend the coloredsurface outside the range of the input data points, the ’c<j>’ coloring options will result in pixels along twoedges of the grid not contributing to the color of any quadrangle. For example, applying the pm3d algorithm
to the 4x4 grid of data points in script demo/pm3d.dem (please have a look) produces only (4-1)x(4-1)=9
colored rectangles.
Borderset pm3d border {retrace} {line-properties}
set pm3d noborderThis option draws bounding lines around each pm3d quadrangle as it is rendered. Additional line properties(linetype, color, linewidth) are optional. By default the border is drawn as a solid black line with width 1.
set pm3d border retrace causes a border to be drawn in the same color as the quadrangle. In principle
this should give the same result as noborder, but some output modes can suffer from antialiasing artifacts
between adjacent filled quadrangles. Retracing the border hides these artifacts, at the cost of a larger output
file.
Fillcolor
splot FOO with pm3d fillcolor <colorspec>

Plot style with pm3d accepts an optional fillcolor in the splot command. This specification is applied tothe entire pm3d surface. See colorspec (p. 57). Most fillcolor specifications will result in a single solid
color, which is hard to interpret visually unless there is also a lighting model present to distinguish surface
components based on orientation. See pm3d lighting (p. 207).
There are a few special cases. with pm3d fillcolor palette would produce the same result as the default
pm3d palette-based coloring, and is therefore not a useful option. with pm3d fillcolor linestyle N ismore interesting. This variant assigns distinct colors to the top and bottom of the pm3d surface, similar
to the color scheme used by gnuplot’s hidden3d mode. Linestyle N is used for the top surface; linestyle
N+1 for the bottom surface. Note that "top" and "bottom" depend on the scan order, so that the colors
are inverted for pm3d scansbackward as compared to pm3d scansforward. This coloring option works
best with pm3d depthorder, however, which unfortunately does not allow you to control the scan orderso you may have to instead swap the colors defined for linestyles N and N+1.
Interpolate
The option interpolate m,n will interpolate between grid points to generate a finer mesh. For data files, thissmooths the color surface and enhances the contrast of spikes in the surface. When working with functions,interpolation makes little sense. It would usually make more sense to increase samples and isosamples.

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For positive m and n, each quadrangle or triangle is interpolated m-times and n-times in the respective
direction. For negative m and n, the interpolation frequency is chosen so that there will be at least |m| and|n| points drawn; you can consider this as a special gridding function.
Note: interpolate 0,0, will automatically choose an optimal number of interpolated surface points.
Note: Currently color interpolation is always linear, even if corners2color is set to a nonlinear scheme suchas the geometric mean.
Deprecated options
The deprecated option set pm3d map was equivalent to set pm3d at b; set view map; set style datapm3d; set style func pm3d;
The deprecated option set pm3d hidden3d N was equivalent to set pm3d border ls N.

Pointintervalbox
The pointinterval and pointnumber properties of a line type are used only in plot style linespoints. A
negative value of pointinterval or pointnumber, e.g. -N, means that before the selected set of point symbols
are drawn a box (actually circle) behind each point symbol is blanked out by filling with the backgroundcolor. The command set pointintervalbox controls the radius of this blanked-out region. It is a multiplierfor the default radius, which is equal to the point size. unset pointintervalbox draws no blanked-out
region.

Pointsize
The set pointsize command scales the size of the points used in plots.
Syntax:set pointsize <multiplier>show pointsize

The default is a multiplier of 1.0. Larger pointsizes may be useful to make points more visible in bitmappedgraphics.
The pointsize of a single plot may be changed on the plot command. See plot with (p. 143) for details.
Please note that the pointsize setting is not supported by all terminal types.

Polar
The set polar command changes the meaning of the plot from rectangular coordinates to polar coordinates.
Syntax:set polar
set polar grid <grid options>unset polarshow polar

In polar coordinates, the dummy variable (t) represents an angle theta. The default range of t is [0:2*pi], or[0:360] if degree units have been selected (see set angles (p. 149)).
The command unset polar changes the meaning of the plot back to the default rectangular coordinate
system.
The set polar command affects only 2D plotting. See the set mapping (p. 185) command for analogous
3D functionality.

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While in polar coordinates the meaning of an expression in t is really r = f(t), where t is an angle of rotation.
The trange controls the domain (the angle) of the function. The r, x and y ranges control the extent of
the graph in the x and y directions. Each of these ranges, as well as the rrange, may be autoscaled or set
explicitly. For details, see set rrange (p. 213) and set xrange (p. 233).
Example:set polar
plot t*sin(t)set trange [-2*pi:2*pi]
set rrange [0:3]
plot t*sin(t)The first plot uses the default polar angular domain of 0 to 2*pi. The radius and the size of the graph are
scaled automatically. The second plot expands the domain, and restricts the size of the graph to the area
within 3 units of the origin. This has the effect of limiting x and y to [-3:3].
By default polar plots are oriented such that theta=0 is at the far right, with theta increasing counterclockwise. You can change both the origin and the sense explicitly. See set theta (p. 224).
You may want to set size square to have gnuplot try to make the aspect ratio equal to unity, so thatcircles look circular. Tic marks around the perimeter can be specified using set ttics. See also polar demos(polar.dem)
and polar data plot (poldat.dem).
Polar grid
Syntax:set polar grid {<theta_segments>, <radial_segments>}{ qnorm {<power>} | gauss | cauchy | exp | box | hann }{ kdensity } { scale <scale> }{theta [min:max]} {r [min:max]}

The polar grid settings are used in conjunction with the plot style with surface to generate a heat map
from a set of polar coordinate points. The surface consists of a grid filling a circle divided into segments
formed by discrete ranges on theta and r.
Each segment is assigned a value derived from the input set of individual scattered points [x,y,z] by applying
a filter operation. The default filter is qnorm 1, which averages each point’s z value weighted by the inverseof the point’s distance from the center of that grid segment.
Alternative filter operations gauss, cauchy, exp, box, and hann are described in more detail elsewhere. See
dgrid3d (p. 164).
kdensity: This keyword tells the program to use the weighted sum of contributions from all points rather
than the weighted average.
scale: This scale facter (default 1.0) is applied to all distances prior to using them in the weighting calculation.
Masking: All input points are used to calculate grid values. The full gridded surface always spans theta
range [0:360] and the radial defined by autoscaling or by a previous set rrange command. However the
portion of the surface that actually appears in the plot can be restricted to a truncated wedge bounded bylower and upper limits on theta and r. Theta limits must be given in degrees.
For example the following commands will generate a plot
which is auto-scaled in size to show all input points.
The contributions of all input points are summed, notaveraged (kdensity), and only a wedge of the resulting
gridded surface is displayed.
set rrange [0:*]set polar grid qnorm kdensity theta [0:190]
plot DATA with surface, DATA with points

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Print
The set print command redirects the output of the print command.
Syntax:set print
set print "-"set print "<filename>" [append]
set print "|<shell_command>"set print $datablock [append]

set print with no parameters restores output to <STDERR>. The <filename> "-" means <STDOUT>.
The append flag causes the file to be opened in append mode. A <filename> starting with "|" is opened
as a pipe to the <shell command> on platforms that support piping.
The destination for print commands can also be a named data block. Data block names start with ’$’,
see also inline data (p. 55). When printing a string to a data block, embedded newline characters are
expanded to generate multiple data block entries.

Psdir
The set psdir <directory> command controls the search path used by the postscript terminal to findprologue.ps and character encoding files. You can use this mechanism to switch between different sets oflocally-customized prolog files. The search order is1) The directory specified by `set psdir`, if any2) The directory specified by environmental variable GNUPLOT_PS_DIR
3) A built-in header or one from the default system directory4) Directories set by `set loadpath`

Raxis
The commands set raxis and unset raxis toggle whether the polar axis is drawn separately from grid lines
and the x axis. If the minimum of the current rrange is non-zero (and not autoscaled), then a white circle isdrawn at the center of the polar plot to indicate that the plot lines and axes do not reach 0. The axis line isdrawn using the same line type as the plot border. See polar (p. 210), rrange (p. 213), rtics (p. 213),
rlabel (p. 212), set grid (p. 171).

Rgbmax
Syntax:set rgbmax {1.0 | 255}
unset rgbmax

The red/green/blue color components of an rgbimage plot are by default interpreted as integers in the range[0:255]. set rgbmax 1.0 tells the program that data values used to generate the color components of a plot
with rgbimage or rgbalpha are floating point values in the range [0:1]. unset rgbmax returns to thedefault integer range [0:255].

RlabelThis command places a label above the r axis. The label will be drawn whether or not the plot is in polar
mode. See set xlabel (p. 232) for additional keywords.

Rmargin
The command set rmargin sets the size of the right margin. Please see set margin (p. 185) for details.

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RrangeThe set rrange command sets the range of the radial coordinate for a graph in polar mode. This has theeffect of setting both xrange and yrange as well. The resulting xrange and yrange are both [-(rmax-rmin) :+(rmax-rmin)]. However if you later change the x or y range, for example by zooming, this does not change
rrange, so data points continue to be clipped against rrange. Unlike other axes, autoscaling the raxis always
results in rmin = 0. The reverse autoscaling flag is ignored. Note: Setting a negative value for rmin may
produce unexpected results.

Rtics
The set rtics command places tics along the polar axis. The tics and labels are drawn to the right of theorigin. The mirror keyword causes them to be drawn also to the left of the origin. See polar (p. 210),
set xtics (p. 235), and set mxtics (p. 191) for discussion of keywords.

Samples
Function plots are constructed by sampling the function at a given number of x values and drawing line
segments to connect the values f(x0)..f(x1)..f(x2)... The default sampling rate for functions, or for interpolating data, may be changed by the set samples command. To change the sampling range for a particularcomponent of a plot or splot command, see plot sampling (p. 140).
Syntax:set samples <samples_1> {,<samples_2>}
show samples

By default, sampling is set to 100 points. A higher sampling rate will produce more accurate plots, but willtake longer. This parameter has no effect on data file plotting unless one of the interpolation/approximation
options is used. See plot smooth (p. 131), set cntrparam (p. 157) and set dgrid3d (p. 164).
When a 2D graph is being done, only the value of <samples 1> is relevant.
When a surface plot is being done without the removal of hidden lines, the value of samples specifies thenumber of samples that are to be evaluated for the isolines. Each iso-v line will have <sample 1> samples
and each iso-u line will have <sample 2> samples. If you only specify <samples 1>, <samples 2> will be
set equal to <samples 1>. See also set isosamples (p. 174).

Size
Syntax:set size {{no}square | ratio <r> | noratio} {<xscale>,<yscale>}show size

The <xscale> and <yscale> values are scale factors for the size of the plot, which includes the graph, labels,
and margins.
Historical note: In early versions of gnuplot some terminal types used set size to control also the size of theoutput canvas. Now there are two distinct properties: ’set size’ and ’set term ... size’.
set term <terminal type> size <x units>, <y units> controls the size of the output file, or canvas.
Please see individual terminal documentation for the units of the size parameters. By default, the plot will
fill this canvas.
set size <xscale>, <yscale> scales the plot itself relative to the size of the canvas. Scale values less than
1.0 cause the plot to fill only part of the canvas. This can be used together with multiplot to inset a small
plot inside a larger plot or to place several small plots side-by-side. Scale values greater than 1.0 are notsupported and may cause errors.

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ratio causes gnuplot to try to create a graph with an aspect ratio of <r> (the ratio of the y-axis length tothe x-axis length) within the portion of the plot specified by <xscale> and <yscale>.
The meaning of a negative value for <r> is different. If <r>=-1, gnuplot tries to set the scales so thatthe unit length along on both the x and y axes is the same; i.e. they are isotropic. See also set isotropic(p. 174). This is the 2D equivalent to the 3D command set view equal xy. If <r>=-2, the unit on y has
twice the length of the unit on x, and so on. See also set isotropic (p. 174).
The success of gnuplot in producing the requested aspect ratio depends on the terminal selected. The grapharea will be the largest rectangle of aspect ratio <r> that will fit into the specified portion of the output(leaving adequate margins, of course).
set size square is a synonym for set size ratio 1.
Both noratio and nosquare return the graph to the default aspect ratio of the terminal, but do not return<xscale> or <yscale> to their default values (1.0).
ratio and square have no effect on 3D plots, but do affect 3D projections created using set view map.
See also set view equal (p. 229), which forces the x and y axes of a 3D onto the same scale.
Examples:To set the size so that the plot fills the available canvas:
set size 1,1

To make the graph half size and square use:
set size square 0.5,0.5

To make the graph twice as high as wide use:
set size ratio 2

Spiderplot
The set spiderplot command switches interpretation of coordinates to a polar system in which each data
point is mapped to a position along a radial axis. paxis 1 is always vertical; axes 2 to N proceed clockwisewith even spacing. The command must be issued prior to plotting. It has additional effects equivalent to
set style data spiderplot
unset borderunset tics
set key noautotitle
set size ratio 1.0

Use reset to restore these after plotting.

Style
Default plotting styles are chosen with the set style data and set style function commands. See plot
with (p. 143) for information about how to override the default plotting style for individual functions anddata sets. See plotting styles (p. 71) or plot with (p. 143) for a complete list of styles.
Syntax:set style function <style>set style data <style>show style function
show style data

Default styles for specific plotting elements may also be set.
Syntax:gnuplot 6.0

215

set style arrow <n> <arrowstyle>set style boxplot <boxplot style options>
set style circle radius <size> {clip|noclip}
set style ellipse size <size> units {xy|xx|yy} {clip|noclip}
set style fill <fillstyle>set style histogram <histogram style options>
set style line <n> <linestyle>set style rectangle <object options> <linestyle> <fillstyle>set style textbox {<n>} {opaque|transparent} {{no}border} {fillcolor}
set style watchpoint labels <label options>

Set style arrow
You can use set style arrow to define a set of arrow types. Each type has its own width, point type,
color, etc so that you can refer to them later by an index instead of repeating all the information at each
invocation.
Syntax:set style arrow <index> default
set style arrow <index> {nohead | head | backhead | heads}{size <length>,<angle>{,<backangle>} {fixed}}{filled | empty | nofilled | noborder}{front | back}{ {linestyle | ls <line_style>}| {linetype | lt <line_type>}{linewidth | lw <line_width}{linecolor | lc <colorspec>}{dashtype | dt <dashtype>} }unset style arrow
show style arrow<index> is an integer that identifies the arrowstyle.
If default is given all arrow style parameters are set to their default values.
If the linestyle <index> already exists, only the given parameters are changed while all others are preserved.
If not, all undefined values are set to the default values.
An arrow style invoked from a plot or splot command can include a data-dependent linecolor (lc variable
or lc rgb variable) that consumes an additional column of data in the corresponding using specification.
In this case the style is probably not useful for individual arrows created by set arrow.
Specifying nohead produces arrows drawn without a head — a line segment. This gives you yet anotherway to draw a line segment on the plot. By default, arrows have one head. Specifying heads draws arrowheads on both ends of the line.
Head size can be modified using size <length>,<angle> or size <length>,<angle>,<backangle>,
where <length> defines length of each branch of the arrow head and <angle> the angle (in degrees) they
make with the arrow. <Length> is in x-axis units; this can be changed by first, second, graph, screen,or character before the <length>; see coordinates (p. 33) for details.
By default the size of the arrow head is reduced for very short arrows. This can be disabled using the fixedkeyword after the size command.
<backangle> is the angle (in degrees) the back branches make with the arrow (in the same direction as<angle>). It is ignored if the style is nofilled.
Specifying filled produces filled arrow heads with a border line around the arrow head. Specifying noborderproduces filled arrow heads with no border. In this case the tip of the arrow head lies exactly on the endpointof the vector and the arrow head is slightly smaller overall. Dashed arrows should always use noborder,
since a dashed border is ugly. Not all terminals support filled arrow heads.
The line style may be selected from a user-defined list of line styles (see set style line (p. 218)) or
may be defined here by providing values for <line type> (an index from the default list of styles) and/or<line width> (which is a multiplier for the default width).

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Note, however, that if a user-defined line style has been selected, its properties (type and width) cannot bealtered merely by issuing another set style arrow command with the appropriate index and lt or lw.
If front is given, the arrows are written on top of the graphed data. If back is given (the default), the arrowis written underneath the graphed data. Using front will prevent a arrow from being obscured by dense
data.
Examples:To draw an arrow without an arrow head and double width, use:
set style arrow 1 nohead lw 2
set arrow arrowstyle 1

See also set arrow (p. 150) for further examples.
Boxplot
The set style boxplot command allows you to change the layout of plots created using the boxplot plot
style.
Syntax:set style boxplot {range <r> | fraction <f>}{{no}outliers} {pointtype <p>}{candlesticks | financebars}{medianlinewidth <width>}{separation <x>}{labels off | auto | x | x2}{sorted | unsorted}

The box in the boxplot always spans the range of values from the first quartile to the third quartile of thedata points. The limit of the whiskers that extend from the box can be controlled in two different ways. By
default the whiskers extend from each end of the box for a range equal to 1.5 times the interquartile range(i.e. the vertical height of the box proper). Each whisker is truncated back toward the median so that it
terminates at a y value belonging to some point in the data set. Since there may be no point whose value isexactly 1.5 times the interquartile distance, the whisker may be shorter than its nominal range. This default
corresponds to
set style boxplot range 1.5

Alternatively, you can specify the fraction of the total number of points that the whiskers should span. In
this case the range is extended symmetrically from the median value until it encompasses the requested
fraction of the data set. Here again each whisker is constrained to end at a point in the data set. To span
95% of the points in the set
set style boxplot fraction 0.95

Any points that lie outside the range of the whiskers are considered outliers. By default these are drawn as
individual circles (pointtype 7). The option nooutliers disables this. If outliers are not drawn they do notcontribute to autoscaling.
By default boxplots are drawn in a style similar to candlesticks, but you have the option of using instead astyle similar to finance bars.
A crossbar indicating the median is drawn using the same line type as box boundary. If you want a thicker
line for the medianset style boxplot medianlinewidth 2.0

If you want no median line, set this to 0.
If the using specification for a boxplot contains a fourth column, the values in that column will be interpreted
as the discrete leveles of a factor variable. In this case more than one boxplots may be drawn, as many as
the number of levels of the factor variable. These boxplots will be drawn next to each other, the distance
between them is 1.0 by default (in x-axis units). This distance can be changed by the option separation.

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217

The labels option governs how and where these boxplots (each representing a part of the dataset) arelabeled. By default the value of the factor is put as a tick label on the horizontal axis – x or x2, dependingon which one is used for the plot itself. This setting corresponds to option labels auto. The labels can beforced to use either of the x or x2 axes – options labels x and labels x2, respectively –, or they can beturned off altogether with the option labels off.
By default the boxplots corresponding to different levels of the factor variable are not sorted; they will
be drawn in the same order the levels are encountered in the data file. This behavior corresponds to theunsorted option. If the sorted option is active, the levels are first sorted alphabetically, and the boxplots
are drawn in the sorted order.
The separation, labels, sorted and unsorted option only have an effect if a fourth column is given theplot specification.
See boxplot (p. 74), candlesticks (p. 75), financebars (p. 79).
Set style data
The set style data command changes the default plotting style for data plots.
Syntax:set style data <plotting-style>show style data

See plotting styles (p. 71) for the choices. show style data shows the current default data plotting style.
Set style fill
The set style fill command is used to set the default style of the plot elements in plots with boxes, histograms,
candlesticks and filledcurves. This default can be superseded by fillstyles attached to individual plots. Notethat there is a separate default fill style for rectangles created by set obj. See set style rectangle (p. 220).
Syntax:set style fill {empty| {transparent} solid {<density>}| {transparent} pattern {<n>}}{border {lt} {lc <colorspec>} | noborder}

The default fillstyle is empty.
The solid option causes filling with a solid color, if the terminal supports that. The <density> parameter
specifies the intensity of the fill color. At a <density> of 0.0, the box is empty, at <density> of 1.0, the innerarea is of the same color as the current linetype. Some terminal types can vary the density continuously;
others implement only a few levels of partial fill. If no <density> parameter is given, it defaults to 1.
The pattern option causes filling to be done with a fill pattern supplied by the terminal driver. The kindand number of available fill patterns depend on the terminal driver. If multiple datasets using filled boxes
are plotted, the pattern cycles through all available pattern types, starting from pattern <n>, much as theline type cycles for multiple line plots.
The empty option causes filled boxes not to be filled. This is the default.
Fill color (fillcolor <colorspec>) is distinct from fill style. I.e. plot elements or objects can share a fillstyle
while retaining separate colors. In most places where a fillstyle is accepted you can also specify a fill color.
Fillcolor may be abbreviated fc. Otherwise the fill color is take from the current linetype. Example:
plot FOO with boxes fillstyle solid 1.0 fillcolor "cyan"

Set style fill border The bare keyword border causes the filled object to be surrounded by a solid lineof the current linetype and color. You can change the color of this line by adding either a linetype or alinecolor. noborder specifies that no bounding line is drawn. Examples:

218

gnuplot 6.0# Half-intensity fill, full intensity border in same color
set style fill solid 0.5 border# Half-transparent fill, solid black border (linetype -1)
set style fill transparent solid 0.5 border -1# Pattern fill in current color, border using color of linetype 5plot ... with boxes fillstyle pattern 2 border lt 5
# Fill area in cyan, border in blue
plot ... with boxes fillcolor "cyan" fs solid border linecolor "blue"

Note: The border property of a fill style only affects plots drawn with filledcurves in the default mode(closed curve).
Set style fill transparent Some terminals support the attribute transparent for filled areas. In thecase of transparent solid fill areas, the density parameter is interpreted as an alpha value; that is, density 0
is fully transparent, density 1 is fully opaque. In the case of transparent pattern fill, the background of thepattern is either fully transparent or fully opaque.
Note that there may be additional limitations on the creation or viewing of graphs containing transparent
fill areas. For example, the png terminal can only use transparent fill if the "truecolor" option is set. Somepdf viewers may not correctly display the fill areas even if they are correctly described in the pdf file.
Ghostscript/gv does not correctly display pattern-fill areas even though actual PostScript printers generally
have no problem.
Set style function
The set style function command changes the default plotting style for function plots (e.g. lines, points,
filledcurves). See plotting styles (p. 71).
Syntax:set style function <plotting-style>show style function

Set style histogram
See histograms (p. 82).
Set style increment
By default, successive plots within the same graph will use successive linetypes. set style increment
userstyles changed this to step through successive user-defined line styles instead.
DEPRECATED. Instead use set linetype to redefine a convenient range of linetypes for the program touse. See set linetype (p. 182).
Set style line
Each terminal has a default set of line and point types, which can be seen by using the command test. setstyle line defines a set of line types and widths and point types and sizes so that you can refer to themlater by an index instead of repeating all the information at each invocation.
Syntax:set style line <index> default
set style line <index> {{linetype | lt} <line_type> | <colorspec>}{{linecolor | lc} <colorspec>}{{linewidth | lw} <line_width>}{{pointtype | pt} <point_type>}{{pointsize | ps} <point_size>}gnuplot 6.0

219{{pointinterval | pi} <interval>}{{pointnumber | pn} <max_symbols>}{{dashtype | dt} <dashtype>}{palette}
unset style line
show style line

default sets all line style parameters to those of the linetype with that same index.
If the linestyle <index> already exists, only the given parameters are changed while all others are preserved.
If not, all undefined values are set to the default values.
Line styles created by this mechanism do not replace the default linetype styles; both may be used. Linestyles are temporary. They are lost whenever you execute a reset command. To redefine the linetype itself,
please see set linetype (p. 182).
The line and point types default to the index value. The exact symbol that is drawn for that index value
may vary from one terminal type to another.
The line width and point size are multipliers for the current terminal’s default width and size (but note that<point size> here is unaffected by the multiplier given by the commandset pointsize).
The pointinterval controls the spacing between points in a plot drawn with style linespoints. The default
is 0 (every point is drawn). For example, set style line N pi 3 defines a linestyle that uses pointtype N,
pointsize and linewidth equal to the current defaults for the terminal, and will draw every 3rd point in plots
using with linespoints. A negative value for the interval is treated the same as a positive value, exceptthat some terminals will try to interrupt the line where it passes through the point symbol.
The pointnumber property is similar to pointinterval except that rather than plotting every Nth point
it limits the total number of points to N.
Not all terminals support the linewidth and pointsize features; if not supported, the option will be ignored.
Terminal-independent colors may be assigned using either linecolor <colorspec> or linetype<colorspec>, abbreviated lc or lt. This requires giving a RGB color triple, a known palette color name, afractional index into the current palette, or a constant value from the current mapping of the palette onto
cbrange. See colors (p. 56), colorspec (p. 57), set palette (p. 198), colornames (p. 160), cbrange(p. 243).
set style line <n> linetype <lt> will set both a terminal-dependent dot/dash pattern and color. The
commandsset style line <n> linecolor <colorspec> or set style line <n> linetype <colorspec>
will set a new line color while leaving the existing dot-dash pattern unchanged.
In 3d mode (splot command), the special keyword palette is allowed as a shorthand for "linetype palettez". The color value corresponds to the z-value (elevation) of the splot, and varies smoothly along a line or
surface.
Examples: Suppose that the default lines for indices 1, 2, and 3 are red, green, and blue, respectively, andthe default point shapes for the same indices are a square, a cross, and a triangle, respectively. Then
set style line 1 lt 2 lw 2 pt 3 ps 0.5

defines a new linestyle that is green and twice the default width and a new pointstyle that is a half-sized
triangle. The commands
set style function lines
plot f(x) lt 3, g(x) ls 1

will create a plot of f(x) using the default blue line and a plot of g(x) using the user-defined wide green line.
Similarly the commands
set style function linespoints
plot p(x) lt 1 pt 3, q(x) ls 1

will create a plot of p(x) using the default triangles connected by a red line and q(x) using small triangles
connected by a green line.
splot sin(sqrt(x*x+y*y))/sqrt(x*x+y*y) w l pal

220gnuplot 6.0

creates a surface plot using smooth colors according to palette. Note, that this works only on some terminals.
See also set palette (p. 198), set pm3d (p. 205).
set style line 10 linetype 1 linecolor rgb "cyan"will assign linestyle 10 to be a solid cyan line on any terminal that supports rgb colors.
Set style circle
Syntax:set style circle {radius {graph|screen} <R>}{{no}wedge}{clip|noclip}

This command sets the default radius used in plot style "with circles". It applies to data plots with only 2columns of data (x,y) and to function plots. The default is "set style circle radius graph 0.02". Nowedge
disables drawing of the two radii that connect the ends of an arc to the center. The default is wedge. Thisparameter has no effect on full circles. Clip clips the circle at the plot boundaries, noclip disables this.
Default is clip.
Set style rectangle
Rectangles defined with the set object command can have individual styles. However, if the object is not
assigned a private style then it inherits a default that is taken from the set style rectangle command.
Syntax:set style rectangle {front|back} {lw|linewidth <lw>}{fillcolor <colorspec>} {fs <fillstyle>}

See colorspec (p. 57) and fillstyle (p. 217). fillcolor may be abbreviated as fc.
Examples:set style rectangle back fc rgb "white" fs solid 1.0 border lt -1
set style rectangle fc linsestyle 3 fs pattern 2 noborder

The default values correspond to solid fill with the background color and a black border.
Set style ellipse
Syntax:set style ellipse {units xx|xy|yy}{size {graph|screen} <a>, {{graph|screen} <b>}}{angle <angle>}{clip|noclip}

This command governs whether the diameters of ellipses are interpreted in the same units or not. Default isxy, which means that the major diameter (first axis) of ellipses will be interpreted in the same units as thex (or x2) axis, while the minor (second) diameter in those of the y (or y2) axis. In this mode the ratio of theellipse axes depends on the scales of the plot axes and aspect ratio of the plot. When set to xx or yy, bothaxes of all ellipses will be interpreted in the same units. This means that the ratio of the axes of the plotted
ellipses will be correct even after rotation, but either their vertical or horizontal extent will not be correct.
This is a global setting that affects all ellipses, both those defined as objects and those generated with theplot command, however, the value of units can also be redefined on a per-plot and per-object basis.
It is also possible to set a default size for ellipses with the size keyword. This default size applies to dataplots with only 2 columns of data (x,y) and to function plots. The two values are interpreted as the major
and minor diameters (as opposed to semi-major and semi-minor axes) of the ellipse.
The default is "set style ellipse size graph 0.05,0.03".

gnuplot 6.0

221Last, but not least it is possible to set the default orientation with the angle keyword. The orientation,
which is defined as the angle between the major axis of the ellipse and the plot’s x axis, must be given indegrees.
Clip clips the ellipse at the plot boundaries, noclip disables this. Default is clip.
For defining ellipse objects, see set object ellipse (p. 195); for the 2D plot style, see ellipses (p. 78).
Set style parallelaxis
Syntax:set style parallelaxis {front|back} {line-properties}

Determines the line type and layer for drawing the vertical axes in plots with parallelaxes. See withparallelaxes (p. 89), set paxis (p. 203).
Set style spiderplot
Syntax:set style spiderplot{fillstyle <fillstyle-properties>}{<line-properties> | <point-properties>}

This commands controls the default appearance of spider plots. The fill, line, and point properties can be
modified in the first component of the plot command. The overall appearance of the plot is also affected byother settings such as set grid spiderplot. See also set paxis (p. 203), spiderplot (p. 93). Example:# Default spider plot will be a polygon with a thick border but no fill
set style spiderplot fillstyle empty border lw 3
# This one will additionally place an open circle (pt 6) at each axis
plot for [i=1:6] DATA pointtype 6 pointsize 3

Set style textbox
Syntax:set style textbox {<boxstyle-index>}{opaque|transparent} {fillcolor <color>}{{no}border {linecolor <colorspec>}}{linewidth <lw>}{margins <xmargin>,<ymargin>}

This command controls the appearance of labels with the attribute ’boxed’. Terminal types that do notsupport boxed text will ignore this style. Note: Implementation for some terminals (svg, latex) is incomplete.
Most terminals cannot place a box correctly around rotated text.
Three numbered textbox styles can be defined. If no boxstyle index <bs> is given, the default (unnumbered)style is changed. Example:# default style has only a black border
set style textbox transparent border lc "black"# style 2 (bs 2) has a light blue background with no border
set style textbox 2 opaque fc "light-cyan" noborder
set label 1 "I'm in a box" boxed
set label 2 "I'm blue" boxed bs 2

Set style watchpoint
Syntax:set style watchpoint nolabels
set style watchpoint labels {label-options}222

gnuplot 6.0

The watchpoint target "mouse" always prints a label to the plot. Other watchpoint targets either print or
do not print a label depending on whether the style is set to label or nolabel.
The appearance of watchpoint labels can be customized using the full range of label properties available
to other gnuplot labels, including font, textcolor, point type and size of a point marking the exact x,ycoordinates. See set label (p. 180).
Currently the text of the label is always autogenerated by the program using the axis tic formats for thecurrent plot to produce the string " x-coordinate : y-coordinate".
Examples:set style watchpoint labels point pt 4 ps 2
set style watchpoint labels font ":Italic,6" textcolor "blue"
set style watchpoint labels boxed offset 1, 0.5

Surface
The set surface command is only relevant for 3D plots (splot).
Syntax:set surface {implicit|explicit}
unset surface
show surface

unset surface will cause splot to not draw points or lines corresponding to any of the function or data file
points. This is mainly useful for drawing only contour lines rather than the surface they were derived from.
Contours may still be drawn on the surface, depending on the set contour option. To turn off the surface
for an individual function or data file while leaving others active, use the nosurface keyword in the splot
command. The combination unset surface; set contour base is useful for displaying contours on the gridbase. See also set contour (p. 160).
If a 3D data set is recognizable as a mesh (grid) then by default the program implicitly treats the plot stylewith lines as requesting a gridded surface. See grid data (p. 249). The command set surface explicit
suppresses this expansion, plotting only the individual lines described by separate blocks of data in the input
file. A gridded surface can still be plotted by explicitly requesting splot with surface.

Table
When table mode is enabled, plot and splot commands print out a multicolumn text table of values
X Y {Z} <flag>

rather than creating an actual plot on the current terminal. The flag character is "i" if the point is in theactive range, "o" if it is out-of-range, or "u" if it is undefined. The data format is determined by the formatof the axis tickmarks (see set format (p. 168)), and the columns are separated by single spaces. This canbe useful if you want to generate contours and then save them for further use. The same method can beused to save interpolated data (see set samples (p. 213) and set dgrid3d (p. 164)).
Syntax:set table {"outfile" | $datablock} {append}{separator {whitespace|tab|comma|"<char>"}}plot <whatever>unset table

Subsequent tabular output is written to "outfile", if specified, otherwise it is written to stdout or othercurrent value of set output. If outfile exists it will be replaced unless the append keyword is given.
Alternatively, tabular output can be redirected to a named data block. Data block names start with ’$’, seealso inline data (p. 55). You must explicitly unset table in order to go back to normal plotting on thecurrent terminal.
The separator character can be used to output csv (comma separated value) files. This mode only affects
plot style with table. See plot with table (p. 223).

gnuplot 6.0

223

Plot with table
This discussion applies only to the special plot style with table.
To avoid any style-dependent processing of the input data being tabulated (filters, smoothing, errorbar
expansion, secondary range checking, etc), or to increase the number of columns that can be tabulated, use
the keyword "table" instead of a normal plot style. In this case the output does not contain an extra column
containing a flag i, o, u indicating inrange/outrange/undefined. The destination for output must first be
specified with set table <where>. For example
set table $DATABLOCK1
plot <file> using 1:2:3:4:($5+$6):(func($7)):8:9:10 with table

Because there is no actual plot style in this case the columns do not correspond to specific axes. Therefore
xrange, yrange, etc are ignored.
If a using term evaluates to a string, the string is tabulated. Numerical data is always written with format%g. If you want some other format use sprintf or gprintf to create a formatted string.
plot <file> using ("File 1"):1:2:3 with table
plot <file> using (sprintf("%4.2f",$1)) : (sprintf("%4.2f",$3)) with table

To create a csv file use
set table "tab.csv" separator comma
plot <foo> using 1:2:3:4 with table[EXPERIMENTAL] To select only a subset of the data points for tabulation you can provide an input filter
condition (if <expression>) at the end of the command. Note that the input filter may reference data
columns that are not part of the output. Details of this feature may change in a future version.
plot <file> using 1:2:($4+$5) with table if (strcol(3) eq "Red")
plot <file> using 1:2:($4+$5) with table if (10. < $1 && $1 < 100.)plot <file> using 1:2:($4+$5) with table if (filter($6,$7) != 0)

Terminal
gnuplot supports many different graphics devices. Use set terminal to tell gnuplot what kind of output
to generate. Use set output to redirect that output to a file or device.
Syntax:set terminal {<terminal-type> | push | pop}
show terminal

If <terminal-type> is omitted, gnuplot will list the available terminal types. <terminal-type> may be
abbreviated.
If both set terminal and set output are used together, it is safest to give set terminal first, becausesome terminals set a flag which is needed in some operating systems.
Some terminals have many additional options. The options used by a previous invocation set term <term><options> of a given <term> are remembered, thus subsequent set term <term> does not reset them.
This helps in printing, for instance, when switching among different terminals — previous options don’t haveto be repeated.
The command set term push remembers the current terminal including its settings while set term pop
restores it. This is equivalent to save term and load term, but without accessing the filesystem. Therefore
they can be used to achieve platform independent restoring of the terminal after printing, for instance. After
gnuplot’s startup, the default terminal or that from startup file is pushed automatically. Therefore portable
scripts can rely that set term pop restores the default terminal on a given platform unless another terminal
has been pushed explicitly.
For more information, see the complete list of terminals (p. 257).

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Termoption
The set termoption command allows you to change the behaviour of the current terminal without requiring
a new set terminal command. Only one option can be changed per command, and only a small number of
options can be changed this way. Currently the only options accepted are
set termoption {no}enhanced
set termoption font "<fontname>{,<fontsize>}"
set termoption fontscale <scale>
set termoption {linewidth <lw>}{lw <lw>} {dashlength <dl>}{dl <dl>}
set termoption {pointscale <scale>} {ps <scale>}

Theta
Polar coordinate plots are by default oriented such that theta = 0 is on the right side of the plot, with theta
increasing as you proceed counterclockwise so that theta = 90 degrees is at the top. set theta allows you
to change the origin and direction of the polar angular coordinate theta.
set theta {right|top|left|bottom}
set theta {clockwise|cw|counterclockwise|ccw}

unset theta restores the default state "set theta right ccw".

Tics
The set tics command controls the tic marks and labels on all axes at once.
The tics may be turned off with the unset tics command, and may be turned on (the default state) with
set tics. Fine control of tics on individual axes is possible using the alternative commands set xtics, set
ztics, etc.
Syntax:set tics {axis | border} {{no}mirror}{in | out} {front | back}{{no}rotate {by <ang>}} {offset <offset> | nooffset}{left | right | center | autojustify}{format "formatstring"} {font "name{,<size>}"} {{no}enhanced}{ textcolor <colorspec> }set tics scale {default | <major> {,<minor>}}unset tics
show tics

The options can be applied to a single axis (x, y, z, x2, y2, cb), e.g.
set xtics rotate by -90
unset cbtics

All tic marks are drawn using the same line properties as the plot border (see set border (p. 153)).
Set tics back or front applies to all axes at once, but only for 2D plots (not splot). It controls whether thetics are placed behind or in front of the plot elements, in the case that there is overlap.
axis or border tells gnuplot to put the tics (both the tics themselves and the accompanying labels) along
the axis or the border, respectively. If the axis is very close to the border, the axis option will move the ticlabels to outside the border in case the border is printed (see set border (p. 153)). The relevant margin
settings will usually be sized badly by the automatic layout algorithm in this case.
mirror tells gnuplot to put unlabeled tics at the same positions on the opposite border. nomirror does
what you think it does.
in and out change the tic marks to be drawn inwards or outwards.
set tics scale controls the size of the tic marks. The first value <major> controls the auto-generated oruser-specified major tics (level 0). The second value controls the auto-generated or user-specified minor tics

gnuplot 6.0

225(level 1). <major> defaults to 1.0, <minor> defaults to <major>/2. Additional values control the size ofuser-specified tics with level 2, 3, ... Default tic sizes are restored by set tics scale default.
rotate asks gnuplot to rotate the text through 90 degrees, which will be done if the terminal driver in
use supports text rotation. norotate cancels this. rotate by <ang> asks for rotation by <ang> degrees,
supported by some terminal types.
The defaults are border mirror norotate for tics on the x and y axes, and border nomirror norotate
for tics on the x2 and y2 axes. For the z axis, the default is nomirror.
The <offset> is specified by either x,y or x,y,z, and may be preceded by first, second, graph, screen,or character to select the coordinate system. <offset> is the offset of the tics texts from their default
positions, while the default coordinate system is character. See coordinates (p. 33) for details. nooffset
switches off the offset.
By default, tic labels are justified automatically depending on the axis and rotation angle to produce aesthetically pleasing results. If this is not desired, justification can be overridden with an explicit left, rightor center keyword. autojustify restores the default behavior.
set tics with no options restores mirrored, inward-facing tic marks for the primary axes. All other settings
are retained.
See also set xtics (p. 235) for more control of major (labeled) tic marks and set mxtics for control ofminor tic marks. These commands provide control of each axis independently.

Ticslevel
Deprecated. See set xyplane (p. 239).

Ticscale
The set ticscale command is deprecated, use set tics scale instead.

Timestamp
The command set timestamp places the current time and date in the plot margin.
Syntax:set timestamp {"<format>"} {top|bottom} {{no}rotate}{offset <xoff>{,<yoff>}} {font "<fontspec>"}{textcolor <colorspec>}
unset timestamp
show timestamp

The format string is used to write the date and time. Its default value is what asctime() uses: "%a %b %d%H:%M:%S %Y" (weekday, month name, day of the month, hours, minutes, seconds, four-digit year). With
top or bottom you can place the timestamp along the top left or bottom left margin (default: bottom).
rotate writes the timestamp vertically. The constants <xoff> and <yoff> are offsets that let you adjust
the position more finely. <font> is used to specify the font with which the time is to be written.
Example:set timestamp "%d/%m/%y %H:%M" offset 80,-2 font "Helvetica"

See set timefmt (p. 225) for more information about time format strings.

Timefmt
This command sets the default format used to input time data. See set xdata time (p. 232), timecolumn(p. 46).

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Syntax:set timefmt "<format string>"
show timefmt

The valid formats for both timefmt and timecolumn are:Format
%d
%m
%y
%Y
%j
%H
%M
%s
%S
%b
%B
%p

Time Series timedata Format Specifiers
Explanation
day of the month, 1–31
month of the year, 1–12
year, 0–99
year, 4-digit
day of the year, 1–365
hour, 0–24
minute, 0–60
seconds since the Unix epoch (1970-01-01 00:00 UTC)
second, integer 0–60 on output, (double) on input
three-character abbreviation of the name of the monthname of the monthtwo character match to one of: am AM pm PM

Any character is allowed in the string, but must match exactly. \t (tab) is recognized. Backslash-octals(\nnn) are converted to char. If there is no separating character between the time/date elements, then %d,%m, %y, %H, %M and %S read two digits each. If a decimal point immediately follows the field read by%S, the decimal and any following digits are interpreted as a fractional second. %Y reads four digits. %jreads three digits. %b requires three characters, and %B requires as many as it needs.
Spaces are treated slightly differently. A space in the string stands for zero or more whitespace charactersin the file. That is, "%H %M" can be used to read "1220" and "12 20" as well as "12 20".
Each set of non-blank characters in the timedata counts as one column in the using n:n specification. Thus
11:11 25/12/76 21.0 consists of three columns. To avoid confusion, gnuplot requires that you provide acomplete using specification if your file contains timedata.
If the date format includes the day or month in words, the format string must exclude this text. But it canstill be printed with the "%a", "%A", "%b", or "%B" specifier. gnuplot will determine the proper monthand weekday from the numerical values. See set format (p. 168) for more details about these and otheroptions for printing time data.
When reading two-digit years with %y, values 69-99 refer to the 20th century, while values 00-68 refer to the
21st century. NB: This is in accordance with the UNIX98 spec, but conventions vary widely and two-digit
year values are inherently ambiguous.
If the %p format returns "am" or "AM", hour 12 will be interpreted as hour 0. If the %p format returns"pm" or "PM", hours < 12 will be increased by 12.
See also set xdata (p. 231) time/date (p. 68) and time specifiers (p. 170) for more information.
Example:set timefmt "%d/%m/%Y\t%H:%M"

tells gnuplot to read date and time separated by tab. (But look closely at your data — what began asa tab may have been converted to spaces somewhere along the line; the format string must match what is
actually in the file.) See also time data demo.

Title
The set title command produces a plot title that is centered at the top of the plot. set title is a special
case of set label.
Syntax:gnuplot 6.0

227

set title {"<title-text>"} {offset <offset>} {font "<font>{,<size>}"}{{textcolor | tc} {<colorspec> | default}} {{no}enhanced}
show title

If <offset> is specified by either x,y or x,y,z the title is moved by the given offset. It may be preceded byfirst, second, graph, screen, or character to select the coordinate system. See coordinates (p. 33) for
details. By default, the character coordinate system is used. For example, "set title offset 0,-1" willchange only the y offset of the title, moving the title down by roughly the height of one character. The sizeof a character depends on both the font and the terminal.
<font> is used to specify the font with which the title is to be written; the units of the font <size> depend
upon which terminal is used.
textcolor <colorspec> changes the color of the text. <colorspec> can be a linetype, an rgb color, or apalette mapping. See help for colorspec (p. 57) and palette (p. 42).
noenhanced requests that the title not be processed by the enhanced text mode parser, even if enhanced
text mode is currently active.
set title with no parameters clears the title.
See syntax (p. 67) for details about the processing of backslash sequences and the distinction between
single- and double-quotes.

Tmargin
The command set tmargin sets the size of the top margin. Please see set margin (p. 185) for details.

TrangeSyntax: set trange [tmin:tmax] The range of the parametric variable t is useful in three contexts.
• In parametric mode plot commands it limits the range of sampling for both generating functions. See
set parametric (p. 203), set samples (p. 213).
• In polar mode plot commands it limits or defines the acceptable range of the angular parameter theta
during input. Data points with theta value outside this range are excluded from the plot even if theywould otherwise lie inside the plot boundary. See polar (p. 210).
• In plot or splot commands using 1-dimensional sampled data via the pseudofile "+". See sampling
1D (p. 140), special-filenames (p. 134).

Ttics
The set ttics command places tics around the perimeter of a polar plot. This is the border if set borderpolar is enabled, otherwise the outermost circle of the polar grid drawn at the rightmost ticmark along ther axis. See set grid (p. 171), set rtics (p. 213). The angular position is always labeled in degrees. The
full perimeter can be labeled regardless of the current trange setting. The desired range of the tic labels
should be given as shown below. Additional properties of the tic marks can be set. See xtics (p. 235).
set ttics -180, 30, 180
set ttics add ("Theta = 0" 0)
set ttics font ":Italic" rotate

UrangeSyntax: set urange [umin:umax] The range of the parametric variables u and v is useful in two contexts.
1) splot in parametric mode. See set parametric (p. 203), set isosamples (p. 174). 2) generating
2-dimension sampled data for either plot or splot using the pseudofile "++". See sampling 2D (p. 141).

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VersionThe show version command lists the version of gnuplot being run, its last modification date, the copyrightholders, and email addresses for the FAQ, the gnuplot-info mailing list, and reporting bugs–in short, theinformation listed on the screen when the program is invoked interactively.
Syntax:show version {long}Show version long also lists the operating system, configuration and compilation options used when thiscopy of gnuplot was built.

Vgrid
Syntax:set vgrid $gridname {size N}
unset vgrid $gridname
show vgrid

If the named grid already exists, mark it as active (use it for subsequent vfill and voxel operations). If a
new size is given, replace the existing content with a zero-filled N x N x N grid. If a grid with this namedoes not already exist, allocate an N x N x N grid (default N=100), zero the contents, and mark it as active.
Note that grid names must begin with ’$’.
show vgrid lists all currently defined voxel grids. Example output:$vgrid1: (active)
size 100 X 100 X 100
vxrange [-4:4] vyrange[-4:4] vzrange[-4:4]
non-zero voxel values: min 0.061237 max 94.5604
number of zero voxels: 992070(99.21%)

unset vgrid $gridname releases all data structures associated with that voxel grid. The data structures
are also released by reset session. The function voxel(x,y,z) returns the value of the active grid pointnearest that coordinate. See also splot voxel-grids (p. 250).

View
The set view command sets the viewing angle for splots. It controls how the 3D coordinates of the plot aremapped into the 2D screen space. It provides controls for both rotation and scaling of the plotted data, but
supports orthographic projections only. It supports both 3D projection or orthogonal 2D projection into a
2D plot-like map.
Syntax:set view <rot_x>{,{<rot_z>}{,{<scale>}{,<scale_z>}}}set view map {scale <scale>}set view projection {xy|xz|yz}
set view {no}equal {xy|xyz}
set view azimuth <angle>
show view

where <rot x> and <rot z> control the rotation angles (in degrees) in a virtual 3D coordinate systemaligned with the screen such that initially (that is, before the rotations are performed) the screen horizontal
axis is x, screen vertical axis is y, and the axis perpendicular to the screen is z. The first rotation applied is<rot x> around the x axis. The second rotation applied is <rot z> around the new z axis.
Command set view map is used to represent the drawing as a map. It is useful for contour plots or 2D
heatmaps using pm3d mode rather than with image. In the latter case, take care that you properly use
zrange and cbrange for input data point filtering and color range scaling, respectively.

gnuplot 6.0229<rot x> is bounded to the [0:180] range with a default of 60 degrees, while <rot z> is bounded to the [0:360]
range with a default of 30 degrees. <scale> controls the scaling of the entire splot, while <scale z> scales
the z axis only. Both scales default to 1.0.
Examples:set view 60, 30, 1, 1
set view ,,0.5

The first sets all the four default values. The second changes only scale, to 0.5.
Azimuth
set view azimuth <angle-in-degrees>

The setting of azimuth affects the orientation of the z axis in a 3D graph (splot). At the default azimuth =0 the z axis of the plot lies in the plane orthogonal to the screen horizontal. I.e. the projection of the z axis
lies along the screen vertical. Non-zero azimuth rotates the plot about the line of sight through the origin
so that a projection of the z axis is no longer vertical. When azimuth = 90 the z axis is horizontal rather
than vertical. During interactive viewing, hot-key z resets azimuth to 0.
Equal axes
The command set view equal xy forces the unit length of the x and y axes to be on the same scale, andchooses that scale so that the plot will fit on the page. The command set view equal xyz additionally sets
the z axis scale to match the x and y axes; however there is no guarantee that the z axis range will fit within
the plot boundary. See also set isotropic (p. 174). By default all three axes are scaled independently tofill the available area.
See also set xyplane (p. 239).
Projection
Syntax:set view projection {xy|xz|yz}

Rotates the view angles of a 3D plot so that one of the primary planes xy, xz, or yz lies in the plane of theplot. Axis label and tic positioning is adjusted accordingly; tics and labels on the third axis are disabled.
The plot is scaled up to approximately match the size that ’plot’ would generate for the same axis ranges.
set view projection xy is equivalent to set view map.
When the x and y coordinates used to specify objects, labels, arrows and other elements are both provided
as "graph" coordinates, then in projection views they are interpreted as "horizontal/vertical" rather than"x/y".
set key top right at graph 0.95, graph 0.95

# works in any projection

VrangeSyntax: set vrange [vmin:vmax] The range of the parametric variables u and v is useful in two contexts.
1) splot in parametric mode. See set parametric (p. 203), set isosamples (p. 174). 2) generating
2-dimension sampled data for either plot or splot using the pseudofile "++". See sampling 2D (p. 141).

Vxrange
Syntax: set vxrange [vxmin:vxmax]

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Establishes the range of x coordinates spanned by the active voxel grid. Analogous commands set vyrange
and set vzrange exist for the other two dimensions of the voxel grid. If no explicit ranges have been set
prior to the first vclear, vfill, or voxel(x,y,z) = command, vmin and vmax will be copied from the current
values of xrange.

VyrangeSee set vxrange (p. 229)

VzrangeSee set vxrange (p. 229)

Walls
Syntax:set walls
set wall {x0|y0|z0|x1|y1} {<fillstyle>} {fc <fillcolor>}

3D surfaces drawn by splot (p. 245) lie within a normalized unit cube regardless of the x y and z axis ranges.
The bounding walls of this cube are described by theplanes (graph coord x == 0), (graph coord x == 1),
etc. The set walls command renders the walls x0 y0
and z0 as solid surfaces. By default these surfaces aresemi-transparent (fillstyle transparent solid 0.5). You
can customize which walls are drawn and also their individual color and fill style. If you choose to enable walls,
you may also want to use set xyplane 0.

10
5
0
-5
-10
0

2

4

-2

0

2

Example:set wall x0; set wall y1; set wall z0 fillstyle solid 1.0 fillcolor "gray"splot f(x,y) with pm3d fc "goldenrod"

Watchpoints
One or more watchpoints may be set for each component plot in a plot command. All watchpoint targets
and hits from the previous plot command are summarized by the command show watchpoints.
Example:plot DATA using 1:2 smooth cnormal watch y=0.25 watch y=0.5 watch y=0.75
show watchpoints
Plot title:"DATA using 1:2 smooth cnormal"
Watch 1 target y = 0.25
(1 hits)
hit 1
x 50.6 y 0.25
Watch 2 target y = 0.5(1 hits)
hit 1
x 63.6 y 0.5
Watch 3 target y = 0.75
(1 hits)
hit 1
x 68.3 y 0.75

The coordinates of all points satisfying the first watchpoint (y=0.25) are stored in an array WATCH 1. The
points satisfying (y=0.5) are stored in an array WATCH 2, and so on.
Each hit is stored as a complex number with x as the real component and y as the imaginary component.
So the first hit of watchpoint 2 has x = real(WATCH 2[1]) y = imag(WATCH 2[1]). In this example only
the x coordinates of the hits are interesting, as the y coordinates will always match the corresponding target
y value. However if the watchpoint target is a z value or a function f(x,y), neither the x or the y coordinateof a hit is known in advance.

gnuplot 6.0

231

X2dataThe set x2data command sets data on the x2 (top) axis to timeseries (dates/times). Please see set xdata(p. 231).

X2dtics
The set x2dtics command changes tics on the x2 (top) axis to days of the week. Please see set xdtics(p. 232) for details.

X2labelThe set x2label command sets the label for the x2 (top) axis. Please see set xlabel (p. 232).

X2mtics
The set x2mtics command changes tics on the x2 (top) axis to months of the year. Please see set xmtics(p. 233) for details.

X2range
The set x2range command sets the horizontal range that will be displayed on the x2 (top) axis. See set
xrange (p. 233) for the full set of command options. See also set link (p. 183).

X2tics
The set x2tics command controls major (labeled) tics on the x2 (top) axis. Please see set xtics (p. 235)
for details.

X2zeroaxis
The set x2zeroaxis command draws a line at the origin of the x2 (top) axis (y2 = 0). For details, pleasesee set zeroaxis (p. 242).

Xdata
This command controls interpretation of data on the x axis. An analogous command acts on each of theother axes.
Syntax:set xdata {time}show xdata

The same syntax applies to ydata, zdata, x2data, y2data and cbdata.
The time option signals that data represents a time/date in seconds. Gnuplot version 6 stores time tomillisecond precision.
set xdata (with no time keyword) restores data interpretation to normal.

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Time
set xdata time indicates that the x coordinate represents a date or time to millisecond precision. There isan analogous command set ydata time.
There are separate format mechanisms for interpretation of time data on input and output. Input data isread from a file either by using the global timefmt or by using the function timecolumn() as part of the plot
command. These input mechanisms also apply to using time values to set an axis range. See set timefmt(p. 225), timecolumn (p. 46).
Example:set xdata time
set timefmt "%d-%b-%Y"
set xrange ["01-Jan-2013" : "31-Dec-2014"]
plot DATA using 1:2

orplot DATA using (timecolumn(1,"%d-%b-%Y")):2

For output, i.e. tick labels along that axis or coordinates output by mousing, the function ’strftime’ (type"man strftime" on unix to look it up) is used to convert from the internal time in seconds to a string
representation of a date. gnuplot tries to figure out a reasonable format for this. You can customize theformat using either set format x or set xtics format. See time specifiers (p. 170) for a special set oftime format specifiers. See also time/date (p. 68) for more information.

Xdtics
The set xdtics commands converts the x-axis tic marks to days of the week where 0=Sun and 6=Sat.
Overflows are converted modulo 7 to dates. set noxdtics returns the labels to their default values. Similarcommands do the same things for the other axes.
Syntax:set xdtics
unset xdtics
show xdtics

The same syntax applies to ydtics, zdtics, x2dtics, y2dtics and cbdtics.
See also the set format (p. 168) command.

XlabelThe set xlabel command sets the x axis label. Similar commands set labels on the other axes.
Syntax:set xlabel {"<label>"} {offset <offset>} {font "<font>{,<size>}"}{textcolor <colorspec>} {{no}enhanced}{rotate by <degrees> | rotate parallel | norotate}show xlabel

The same syntax applies to x2label, ylabel, y2label, zlabel and cblabel.
If <offset> is specified by either x,y or x,y,z the label is moved by the given offset. It may be preceded byfirst, second, graph, screen, or character to select the coordinate system. See coordinates (p. 33) for
details. By default, the character coordinate system is used. For example, "set xlabel offset -1,0" willchange only the x offset of the title, moving the label roughly one character width to the left. The size of acharacter depends on both the font and the terminal.
<font> is used to specify the font in which the label is written; the units of the font <size> depend uponwhich terminal is used.

gnuplot 6.0

233

noenhanced requests that the label text not be processed by the enhanced text mode parser, even if
enhanced text mode is currently active.
To clear a label, put no options on the command line, e.g., "set y2label".
The default positions of the axis labels are as follows:
xlabel: The x-axis label is centered below the bottom of the plot.
ylabel: The y-axis label is centered to the left of the plot, defaulting to either horizontal or vertical orientation
depending on the terminal type. The program may not reserve enough space to the left of the plot to holdlong non-rotated ylabel text. You can adjust this with set lmargin.
zlabel: The z-axis label is centered along the z axis and placed in the space above the grid level.
cblabel: The color box axis label is centered along the box and placed below or to the right according tohorizontal or vertical color box gradient.
y2label: The y2-axis label is placed to the right of the y2 axis. The position is terminal-dependent in thesame manner as is the y-axis label.
x2label: The x2-axis label is placed above the plot but below the title. It is also possible to create an x2-axislabel by using new-line characters to make a multi-line plot title, e.g.,
set title "This is the title\n\nThis is the x2label"

Note that double quotes must be used. The same font will be used for both lines, of course.
The orientation (rotation angle) of the x, x2, y and y2 axis labels in 2D plots can be changed by specifying
rotate by <degrees>. The orientation of the x and y axis labels in 3D plots defaults to horizontal but
can be changed to run parallel to the axis by specifying rotate parallel.
If you are not satisfied with the default position of an axis label, use set label instead–that command gives
you much more control over where text is placed.
Please see syntax (p. 67) for further information about backslash processing and the difference between
single- and double-quoted strings.

Xmtics
The set xmtics command converts the x-axis tic marks to months of the year where 1=Jan and 12=Dec.
Overflows are converted modulo 12 to months. The tics are returned to their default labels by unset xmtics.
Similar commands perform the same duties for the other axes.
Syntax:set xmtics
unset xmtics
show xmtics

The same syntax applies to x2mtics, ymtics, y2mtics, zmtics and cbmtics.
See also the set format (p. 168) command.

XrangeThe set xrange command sets the horizontal range that will be displayed. A similar command exists foreach of the other axes, as well as for the polar radius r and the parametric variables t, u, and v.
Syntax:set xrange [{{<min>}:{<max>}}] {{no}reverse} {{no}writeback} {{no}extend}| restore
show xrange

where <min> and <max> terms are constants, expressions or an asterisk to set autoscaling. If the data
are time/date, you must give the range as a quoted string according to the set timefmt format. If <min>234

gnuplot 6.0

or <max> is omitted the current value will not be changed. See below for full autoscaling syntax. See also
noextend (p. 152).
The same syntax applies to yrange, zrange, x2range, y2range, cbrange, rrange, trange, urange andvrange.
See set link (p. 183) for options that link the ranges of x and x2, or y and y2.
The reverse option reverses the direction of an autoscaled axis. For example, if the data values range from10 to 100, it will autoscale to the equivalent of set xrange [100:10]. The reverse flag has no effect if the axis
is not autoscaled.
Autoscaling: If <min> (the same applies for correspondingly to <max>) is an asterisk "*" autoscaling isturned on. The range in which autoscaling is being performed may be limited by a lower bound <lb> or an
upper bound <ub> or both. The syntax is{ <lb> < } * { < <ub> }For example,
0 < * < 200

sets <lb> = 0 and <ub> = 200. With such a setting <min> would be autoscaled, but its final value will
be between 0 and 200 (both inclusive despite the ’<’ sign). If no lower or upper bound is specified, the ’<’to also be omitted. If <ub> is lower than <lb> the constraints will be turned off and full autoscaling will
happen. This feature is useful to plot measured data with autoscaling but providing a limit on the range, toclip outliers, or to guarantee a minimum range that will be displayed even if the data would not need sucha big range.
The writeback option essentially saves the range found by autoscale in the buffers that would be filled
by set xrange. This is useful if you wish to plot several functions together but have the range determinedby only some of them. The writeback operation is performed during the plot execution, so it must be
specified before that command. To restore, the last saved horizontal range use set xrange restore. For
example,set xrange [-10:10]
set yrange [] writeback
plot sin(x)set yrange restore
replot x/2

results in a yrange of [-1:1] as found only from the range of sin(x); the [-5:5] range of x/2 is ignored. Executing
show yrange after each command in the above example should help you understand what is going on.
In 2D, xrange and yrange determine the extent of the axes, trange determines the range of the parametricvariable in parametric mode or the range of the angle in polar mode. Similarly in parametric 3D, xrange,
yrange, and zrange govern the axes and urange and vrange govern the parametric variables.
In polar mode, rrange determines the radial range plotted. <rmin> acts as an additive constant to theradius, whereas <rmax> acts as a clip to the radius — no point with radius greater than <rmax> will beplotted. xrange and yrange are affected — the ranges can be set as if the graph was of r(t)-rmin, withrmin added to all the labels.
Any range may be partially or totally autoscaled, although it may not make sense to autoscale a parametricvariable unless it is plotted with data.
Ranges may also be specified on the plot command line. A range given on the plot line will be used forthat single plot command; a range given by a set command will be used for all subsequent plots that do
not specify their own ranges. The same holds true for splot.
ExamplesExamples:To set the xrange to the default:

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set xrange [-10:10]

To set the yrange to increase downwards:
set yrange [10:-10]

To change zmax to 10 without affecting zmin (which may still be autoscaled):
set zrange [:10]

To autoscale xmin while leaving xmax unchanged:
set xrange [*:]

To autoscale xmin but keeping xmin positive:
set xrange [0<*:]To autoscale x but keep minimum range of 10 to 50 (actual might be larger):set xrange [*<10:50<*]

Autoscaling but limit maximum xrange to -1000 to 1000, i.e. autoscaling within [-1000:1000]
set xrange [-1000<*:*<1000]

Make sure xmin is somewhere between -200 and 100:
set xrange [-200<*<100:]

Extendset xrange noextend is the same as set autoscale x noextend. See noextend (p. 152).

Xtics
Fine control of the major (labeled) tics on the x axis is possible with the set xtics command. The tics may
be turned off with the unset xtics command, and may be turned on (the default state) with set xtics.
Similar commands control the major tics on the y, z, x2 and y2 axes.
Syntax:set xtics {axis | border} {{no}mirror}{in | out} {scale {default | <major> {,<minor>}}}{{no}rotate {by <ang>}} {offset <offset> | nooffset}{left | right | center | autojustify}{add}{ autofreq| <incr>| <start>, <incr> {,<end>}| ({"<label>"} <pos> {<level>} {,{"<label>"}...) }{format "formatstring"} {font "name{,<size>}"} {{no}enhanced}{ numeric | timedate | geographic }{{no}logscale}{ rangelimited }{ textcolor <colorspec> }unset xtics
show xtics

The same syntax applies to ytics, ztics, x2tics, y2tics and cbtics.
axis or border tells gnuplot to put the tics (both the tics themselves and the accompanying labels) along
the axis or the border, respectively. If the axis is very close to the border, the axis option will move thetic labels to outside the border. The relevant margin settings will usually be sized badly by the automaticlayout algorithm in this case.
mirror tells gnuplot to put unlabeled tics at the same positions on the opposite border. nomirror does
what you think it does.

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in and out change the tic marks to be drawn inwards or outwards.
With scale, the size of the tic marks can be adjusted. If <minor> is not specified, it is 0.5*<major>. The
default size 1.0 for major tics and 0.5 for minor tics is requested by scale default.
rotate asks gnuplot to rotate the text through 90 degrees, which will be done if the terminal driver in
use supports text rotation. norotate cancels this. rotate by <ang> asks for rotation by <ang> degrees,
supported by some terminal types.
The defaults are border mirror norotate for tics on the x and y axes, and border nomirror norotate
for tics on the x2 and y2 axes. For the z axis, the {axis | border} option is not available and the default
is nomirror. If you do want to mirror the z-axis tics, you might want to create a bit more room for themwith set border.
The <offset> is specified by either x,y or x,y,z, and may be preceded by first, second, graph, screen,or character to select the coordinate system. <offset> is the offset of the tics texts from their default
positions, while the default coordinate system is character. See coordinates (p. 33) for details. nooffset
switches off the offset.
Example:Move xtics more closely to the plot.
set xtics offset 0,graph 0.05

To change the relative order of drawing axis tics and the plot itself, use the set grid command with options’front’, ’back’ or ’layerdefault’. There is no option to assign different axis tics or grid lines to different layers.
By default, tic labels are justified automatically depending on the axis and rotation angle to produce aesthetically pleasing results. If this is not desired, justification can be overridden with an explicit left, rightor center keyword. autojustify restores the default behavior.
set xtics with no options restores the default border or axis if xtics are being displayed; otherwise it has noeffect. Any previously specified tic frequency or position {and labels} are retained.
Tic positions are calculated automatically by default or if the autofreq option is given.
A series of tic positions can be specified by giving either a tic interval alone, or a start point, interval, andend point (see xtics series (p. 236)).
Individual tic positions can be specified individually by providing an explicit list of positions, where eachposition may have an associated text label. See xtics list (p. 237).
However they are specified, tics will only be plotted when in range.
Format (or omission) of the tic labels is controlled by set format, unless the explicit text of a label is
included in the set xtics ("<label>") form.
Minor (unlabeled) tics can be added automatically by the set mxtics command, or at explicit positions by
the set xtics ("" <pos> 1, ...) form.
The appearance of the tics (line style, line width etc.) is determined by the border line (see set border(p. 153)), even if the tics are drawn at the axes.
Xtics series
Syntax:set xtics <incr>
set xtics <start>, <incr>, <end>

The implicit <start>, <incr>, <end> form specifies that a series of tics will be plotted on the axis between
the values <start> and <end> with an increment of <incr>. If <end> is not given, it is assumed to be
infinity. The increment may be negative. If neither <start> nor <end> is given, <start> is assumed to be
negative infinity, <end> is assumed to be positive infinity, and the tics will be drawn at integral multiplesof <incr>. If the axis is logarithmic, the increment will be used as a multiplicative factor.

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If you specify to a negative <start> or <incr> after a numerical value (e.g., rotate by <angle> or offset<offset>), the parser fails because it subtracts <start> or <incr> from that value. As a workaround,
specify 0-<start> resp. 0-<incr> in that case.
Example:set xtics border offset 0,0.5 -5,1,5

Fails with ’invalid expression’ at the last comma. Use instead
set xtics border offset 0,0.5 0-5,1,5

or
set xtics offset 0,0.5 border -5,1,5These place tics at the border, tics text with an offset of 0,0.5 characters, and sets the start, increment, andend to -5, 1, and 5, as requested.
Examples:
Make tics at 0, 0.5, 1, 1.5, ..., 9.5, 10.
set xtics 0,.5,10

Make tics at ..., -10, -5, 0, 5, 10, ...
set xtics 5

Make tics at 1, 100, 1e4, 1e6, 1e8.
set logscale x; set xtics 1,100,1e8

Xtics list
Syntax:set xtics {add} ("label1" <pos1> <level1>, "label2" <pos2> <level2>, ...)The explicit ("label" <pos> <level>, ...) form allows arbitrary tic positions or non-numeric tic labels. In
this form, the tics do not need to be listed in numerical order. Each tic has a position, optionally with alabel.
The label is a string enclosed by quotes or a string-valued expression. It may contain formatting information
for converting the position into its label, such as "%3f clients", or it may be the empty string "". See set
format (p. 168) for more information. If no string is given, the default label (numerical) is used.
An explicit tic mark has a third parameter, the level. The default is level 0, a major tic. Level 1 generates
a minor tic. Labels are never printed for minor tics. Major and minor tics may be auto-generated by the
program or specified explicitly by the user. Tics with level 2 and higher must be explicitly specified by theuser, and take priority over auto-generated tics. The size of tics marks at each level is controlled by thecommand set tics scale.
Examples:set xtics ("low" 0, "medium" 50, "high" 100)
set xtics (1,2,4,8,16,32,64,128,256,512,1024)
set ytics ("bottom" 0, "" 10, "top" 20)set ytics ("bottom" 0, "" 10 1, "top" 20)In the second example, all tics are labeled. In the third, only the end tics are labeled. In the fourth, theunlabeled tic is a minor tic.
Normally if explicit tics are given, they are used instead of auto-generated tics. Conversely if you specify
set xtics auto or the like it will erase any previously specified explicit tics. You can mix explicit and autogenerated tics by using the keyword add, which must appear before the tic style being added.
Example:set xtics 0,.5,10
set xtics add ("Pi" 3.14159)

This will automatically generate tic marks every 0.5 along x, but will also add an explicit labeled tic markat pi.

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Xtics timedata
Times and dates are stored internally as a number of seconds.
Input: Non-numeric time and date values are converted to seconds on input using the format specifier intimefmt. Axis range limits, tic placement, and plot coordinates may be given as quoted dates or times
interpreted using timefmt.
Output: Axis tic labels are generated using a separate format specified either by set format or set xtics
format. By default the usual numeric format specifiers are expected (set xtics numeric). Other options
are geographic coordinates (set xtics geographic), or times or dates (set xtics time).
Note: For backward compatibility with earlier gnuplot versions, the command set xdata time will implicitly
also do set xtics time, and set xdata or unset xdata will implicitly reset to set xtics numeric. However
you can change this with a later call to set xtics.
Examples:set xdata time
# controls interpretation of input data
set timefmt "%d/%m"# format used to read input data
set xtics timedate# controls interpretation of output format
set xtics format "%b %d" # format used for tic labels
set xrange ["01/12":"06/12"]
set xtics "01/12", 172800, "05/12"
set xdata time
set timefmt "%d/%m"
set xtics format "%b %d" time
set xrange ["01/12":"06/12"]
set xtics ("01/12", "" "03/12", "05/12")

Both of these will produce tics "Dec 1", "Dec 3", and "Dec 5", but in the second example the tic at "Dec3" will be unlabeled.
If the <start>, <incr>, <end> form is used, <incr> defaults to seconds but an explicit time unit ofminutes, hours, days, weeks, months, or years can be appended. The same is true if only an interval<incr> is given.
Examplesset xtics time 5 years# place labeled tics at five year intervals
set xtics "01-Jan-2000", 1 month, "01-Jan-2001"

There is also a special time mode for minor tics. See set mxtics time (p. 192).
Geographic
set xtics geographic indicates that x-axis values are to be interpreted as a geographic coordinate measured
in degrees. Use set xtics format or set format x to specify the appearance of the axis tick labels. The
format specifiers for geographic data are as follows:%D%<width.precision>d%M%<width.precision>m%S%<width.precision>s%E%N= integer degrees= floating point degrees= integer minutes= floating point minutes= integer seconds= floating point seconds= label with E/W instead of +/= label with N/S instead of +/-For example, the command set format x "%Ddeg %5.2mmin %E" will cause x coordinate -1.51 to belabeled as " 1deg 30.60min W".
If the xtics are left in the default state (set xtics numeric) the coordinate will be reported as a decimal
number of degrees, and format will be assumed to contain normal numeric format specifiers rather than thespecial set above.

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To output degrees/minutes/seconds in a context other than axis tics, such as placing labels on a map, you
can use the relative time format specifiers %tH %tM %tS for strptime. See time specifiers (p. 170),
strptime (p. 41).
Xtics logscale
If the logscale attribute is set for a tic series along a log-scaled axis, the tic interval is interpreted as amultiplicative factor rather than a constant. For example:# generate a series of tics at y=20 y=200 y=2000 y=20000
set log y
set ytics 20, 10, 50000 logscale

Note that no tic is placed at y=50000 because it is not in the series 2*10^x. If the logscale property isdisabled, the tic increment will be treated as an additive constant even for a log-scaled axis. For example:# generate a series of tics at y=20 y=40 y=60 ... y=200
set log y
set yrange [20:200]
set ytics 20 nologscale

The logscale attribute is set automatically by the set log command, so normally you do not need thiskeyword unless you want to force a constant tic interval as in the second example above.
Xtics rangelimited
This option limits both the auto-generated axis tic labels and the corresponding plot border to the range ofvalues actually present in the data that has been plotted. Note that this is independent of the current range
limits for the plot. For example, suppose that the data in "file.dat" all lies in the range 2 < y < 4. Thenthe following commands will create a plot for which the left-hand plot border (y axis) is drawn for only thisportion of the total y range, and only the axis tics in this region are generated. I.e., the plot will be scaled
to the full range on y, but there will be a gap between 0 and 2 on the left border and another gap between
4 and 10. This style is sometimes referred to as a range-frame graph.
set border 3
set yrange [0:10]
set ytics nomirror rangelimited
plot "file.dat"

Xyplane
The set xyplane command adjusts the position at which the xy plane is drawn in a 3D plot. The synonym"set ticslevel" is accepted for backwards compatibility.
Syntax:set xyplane at <zvalue>
set xyplane relative <frac>
set ticslevel <frac># equivalent to set xyplane relative
show xyplane

The form set xyplane relative <frac> places the xy plane below the range in Z, where the distance fromthe xy plane to Zmin is given as a fraction of the total range in z. The default value is 0.5. Negative values
are permitted, but tic labels on the three axes may overlap.
The alternative form set xyplane at <zvalue> fixes the placement of the xy plane at a specific Z value
regardless of the current z range. Thus to force the x, y, and z axes to meet at a common origin one would
specify set xyplane at 0.
See also set view (p. 228), and set zeroaxis (p. 242).

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Xzeroaxis
The set xzeroaxis command draws a line at y = 0. For details, please see set zeroaxis (p. 242).

Y2dataThe set y2data command sets y2 (right-hand) axis data to timeseries (dates/times). Please see set xdata(p. 231).

Y2dtics
The set y2dtics command changes tics on the y2 (right-hand) axis to days of the week. Please see set
xdtics (p. 232) for details.

Y2labelThe set y2label command sets the label for the y2 (right-hand) axis. Please see set xlabel (p. 232).

Y2mtics
The set y2mtics command changes tics on the y2 (right-hand) axis to months of the year. Please see set
xmtics (p. 233) for details.

Y2range
The set y2range command sets the vertical range that will be displayed on the y2 (right) axis. See set
xrange (p. 233) for the full set of command options. See also set link (p. 183).

Y2tics
The set y2tics command controls major (labeled) tics on the y2 (right-hand) axis. Please see set xtics(p. 235) for details.

Y2zeroaxis
The set y2zeroaxis command draws a line at the origin of the y2 (right-hand) axis (x2 = 0). For details,
please see set zeroaxis (p. 242).

Ydata
The set ydata commands sets y-axis data to timeseries (dates/times). Please see set xdata (p. 231).

Ydtics
The set ydtics command changes tics on the y axis to days of the week. Please see set xdtics (p. 232)
for details.

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YlabelThis command sets the label for the y axis. Please see set xlabel (p. 232).

Ymtics
The set ymtics command changes tics on the y axis to months of the year. Please see set xmtics (p. 233)
for details.

YrangeThe set yrange command sets the vertical range that will be displayed on the y axis. Please see set xrange(p. 233) for details.

Ytics
The set ytics command controls major (labeled) tics on the y axis. Please see set xtics (p. 235) for
details.

Yzeroaxis
The set yzeroaxis command draws a line at x = 0. For details, please see set zeroaxis (p. 242).

Zdata
The set zdata command sets zaxis data to timeseries (dates/times). Please see set xdata (p. 231).

Zdtics
The set zdtics command changes tics on the z axis to days of the week. Please see set xdtics (p. 232)
for details.

Zzeroaxis
The set zzeroaxis command draws a line through (x=0,y=0). This has no effect on 2D plots, including
splot with set view map. For details, please see set zeroaxis (p. 242) and set xyplane (p. 239).

CbdataSet color box axis data to timeseries (dates/times). Please see set xdata (p. 231).

Cbdtics
The set cbdtics command changes tics on the color box axis to days of the week. Please see set xdtics(p. 232) for details.

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Zero
The zero value is the default threshold for values approaching 0.0.
Syntax:set zero <expression>
show zerognuplot will not plot a point if its imaginary part is greater in magnitude than the zero threshold. This
threshold is also used in various other parts of gnuplot as a (crude) numerical-error threshold. The default
zero value is 1e-8. zero values larger than 1e-3 (the reciprocal of the number of pixels in a typical bitmap
display) should probably be avoided, but it is not unreasonable to set zero to 0.0.

Zeroaxis
The x axis may be drawn by set xzeroaxis and removed by unset xzeroaxis. Similar commands behave
similarly for the y, x2, y2, and z axes. set zeroaxis ... (no prefix) acts on the x, y, and z axes jointly.
Syntax:set {x|x2|y|y2|z}zeroaxis { {linestyle | ls <line_style>}| {linetype | lt <line_type>}{linewidth | lw <line_width>}{linecolor | lc <colorspec>}{dashtype | dt <dashtype>} }unset {x|x2|y|y2|z}zeroaxis
show {x|y|z}zeroaxis

By default, these options are off. The selected zero axis is drawn with a line of type <line type>, width<line width>, color <colorspec>, and dash type <dashtype> (if supported by the terminal driver currently
in use), or a user-defined style <line style> (see set style line (p. 218)).
If no linetype is specified, any zero axes selected will be drawn using the axis linetype (linetype 0).
Examples:To simply have the y=0 axis drawn visibly:
set xzeroaxis

If you want a thick line in a different color or pattern, instead:set xzeroaxis linetype 3 linewidth 2.5

ZlabelThis command sets the label for the z axis. Please see set xlabel (p. 232).

Zmtics
The set zmtics command changes tics on the z axis to months of the year. Please see set xmtics (p. 233)
for details.

ZrangeThe set zrange command sets the range that will be displayed on the z axis. The zrange is used only by
splot and is ignored by plot. Please see set xrange (p. 233) for details.

Ztics
The set ztics command controls major (labeled) tics on the z axis. Please see set xtics (p. 235) for details.

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CblabelThis command sets the label for the color box axis. Please see set xlabel (p. 232).

Cbmtics
The set cbmtics command changes tics on the color box axis to months of the year. Please see set xmtics(p. 233) for details.

Cbrange
The set cbrange command sets the range of values which are colored using the current palette by styles
with pm3d, with image and with palette. Values outside of the color range use color of the nearest
extreme.
If the cb-axis is autoscaled in splot, then the colorbox range is taken from zrange. Points drawn in splot... pm3d|palette can be filtered by using different zrange and cbrange.
Please see set xrange (p. 233) for details on set cbrange (p. 243) syntax. See also set palette (p. 198)and set colorbox (p. 159).

Cbtics
The set cbtics command controls major (labeled) tics on the color box axis. Please see set xtics (p. 235)
for details.

Shell
The shell command spawns an interactive shell. To return to gnuplot, type exit or the END-OF-FILE
character if using Unix, or exit if using MS-DOS or OS/2.
The shell command ignores anything else on the gnuplot command line. If instead you want to pass a
command string to a shell for immediate execution, use the system function or the shortcut !. See system(p. 253).
Examples:shellsystem "print previous_plot.ps"! print previous_plot.ps
current_time = system("date")

Show
Most set commands have a corresponding show command with no special options. For example
show linetype 3

will report the current properties in effect from previous commands likeset linetype 3 linewidth 2 dashpattern '.-'

A few show commands that diverge from this pattern are documented separately.

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Show colornames
Gnuplot knows about 100 colors by name (see colornames (p. 160)). You can dump a list of these to theterminal by using the command show colornames. There is currently no way to set new names.

Show functions
The show functions command lists all user-defined functions and their definitions.
Syntax:show functions

For information about the definition and usage of functions in gnuplot, please see expressions (p. 36).
See also splines as user defined functions (spline.dem)
and use of functions and complex variables for airfoils (airfoil.dem).

Show palette
Syntax:show paletteshow palette palette {<ncolors>} {{float | int | hex}}
show palette gradientshow palette rgbformulae
test palette

The test palette command will plot the R,G,B profiles for the current palette and store the profile values
in a datablock $PALETTE.
Show palette gradientshow palette gradient displays the piecewise gradient established by a prior set palette defined command. If the current palette is based on rgbformulae or a set of predefined values then this command doesnothing.
Show palette paletteshow palette palette {<ncolors>} {{float | int | hex}}

show palette palette <n> prints to the screen or to the file given by set print a table of color components
for each entry in the current palette. By default the continuous palette is sampled in 128 increments.
Specifying <ncolors> will sample the palette evenly at this number of increments (rather than 128). The
default is a long listing in the form
0. gray=0.0000, (r,g,b)=(0.0000,0.0000,0.0000), #000000 =0
1. gray=0.1111, (r,g,b)=(0.3333,0.0014,0.6428), #5500a4 = 85
2. gray=0.2222, (r,g,b)=(0.4714,0.0110,0.9848), #7803fb = 120
...

0
0
0 164
3 251

An optional trailing keyword float, int, or hex instead prints only single representation of the color components per entry:
int:float:
hex:

85
0.33330x5500a4

00.0014164
0.6428

By using set print to direct this output to a file, the current gnuplot color palette can be loaded into otherimaging applications such as Octave.
By using set print to direct output to a datablock, the current palette can be saved so that it is available
to future plot commands even if the active palette is redefined. This allows creating plots that draw frommultiple palettes, although the colorbox still represents only the current active palette.

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245Show palette rgbformulae
show palette rgbformulae prints the available fixed gray –> color transformation formulae. It does notshow the state of the current palette.

Show plot
The show plot command shows the most recent plotting command as it results from the last plot and/or
splot and possible subsequent replot commands.
In addition, the show plot add2history command adds this current plot command into the history. It
is useful if you have used replot to add more curves to the current plot and you want to edit the wholecommand now.

Show variables
The show variables command lists the current value of user-defined and internal variables. Gnuplot
internally defines variables whose names begin with GPVAL , MOUSE , FIT , and TERM .
Syntax:show variables# show variables that do not begin with GPVAL_
show variables all # show all variables including those beginning GPVAL_
show variables NAME # show only variables beginning with NAME

Splot
splot is the command for drawing 3D plots (well, actually projections on a 2D surface, but you knew that).
It is the 3D equivalent of the plot command. splot provides only a single x, y, and z axis; there is noequivalent to the x2 and y2 secondary axes provided by plot.
See the plot (p. 120) command for many options available in both 2D and 3D plots.
Syntax:splot {<ranges>}{<iteration>}<function> | {{<file name> | <datablock name>} {datafile-modifiers}}| <voxelgridname>| keyentry{<title-spec>} {with <style>}{, {definitions{,}} <function> ...}The splot command operates on a data generated by a function, read from a data file, or stored previously
in a named data block. Data file names are usually provided as a quoted string. The function can be amathematical expression, or a triple of mathematical expressions in parametric mode.
Starting in version 5.4 splot can operate on voxel data. See voxel-grids (p. 250), set vgrid (p. 228),
vxrange (p. 229). At present voxel grids can be be plotted using styles with dots, with points, or withisosurface. Voxel grid values can also be referenced in the using specifiers of other plot styles, for example
to assign colors.
By default splot draws the xy plane completely below the plotted data. The offset between the lowest ztic
and the xy plane can be changed by set xyplane. The orientation of a splot projection is controlled by
set view. See set view (p. 228) and set xyplane (p. 239) for more information.
The syntax for setting ranges on the splot command is the same as for plot. In non-parametric mode,
ranges must be given in the order
splot [<xrange>][<yrange>][<zrange>] ...

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splot [<urange>][<vrange>][<xrange>][<yrange>][<zrange>] ...

The title option is the same as in plot. The operation of with is also the same as in plot except that not
all 2D plotting styles are available.
The datafile options have more differences.
As an alternative to surfaces drawn using parametric or function mode, the pseudo-file ’++’ can be used togenerate samples on a grid in the xy plane.
See also show plot (p. 245), set view map (p. 228), and sampling (p. 140).

Data-file
Splot, like plot, can display from a file.
Syntax:splot '<file_name>' {binary <binary list>}{{nonuniform|sparse} matrix}{index <index list>}{every <every list>}{using <using list>}

The special filenames "" and "-" are permitted, as in plot. See special-filenames (p. 134).
Keywords binary and matrix indicate that the data are in a special form, index selects which data sets ina multi-data-set file are plotted, every specifies a subset of lines within a single data set, using determines
how the columns within a single record are interpreted.
The options index and every behave the same way as with plot; using does so also, except that the using
list must provide three entries instead of two.
The plot option smooth is not available for splot, but cntrparam and dgrid3d provide limited smoothing
capabilities.
Data file organization is essentially the same as for plot, except that each point is an (x,y,z) triple. If onlya single value is provided, it will be used for z, the block number will be used for y, and the index of thedata point in the block will be used for x. If two or four values are provided, gnuplot uses the last value
for calculating the color in pm3d plots. Three values are interpreted as an (x,y,z) triple. Additional values
are generally used as errors, which can be used by fit.
Single blank records separate blocks of data in a splot datafile; splot treats blocks as the equivalent offunction y-isolines. No line will join points separated by a blank record. If all blocks contain the same
number of points, gnuplot will draw cross-isolines between points in the blocks, connecting corresponding
points. This is termed "grid data", and is required for drawing a surface, for contouring (set contour) and
hidden-line removal (set hidden3d). See also splot grid data (p. 249).
MatrixMatrix data can be input in several formats (uniform, nonuniform, sparse) from either text or binary
files.
The first variant assumes a uniform grid of x and y coordinates and assigns each value in the input matrix
to one element M[i,j] of this uniform grid. The assigned x coordinates are the integers [0:NCOLS-1]. The
assigned y coordinates are the integers [0:NROWS-1]. This is the default for text data input, but not forbinary input. See uniform (p. 247) for examples and additional keywords.
The second variant handles a non-uniform grid with explicit x and y coordinates. The first row of input datacontains the y coordinates; the first column of input data contains the x coordinates. For binary input data,
the first element of the first row must contain the number of columns. This is the default for binary matrix
input, but requires an additional keyword nonuniform for text input data. See nonuniform (p. 247) for
examples.

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247

The sparse matrix variant defines a uniform grid into which any number of individual point values areread from the input file, one per line, in any order. This is primarily intended for the generation of heatmaps
from incomplete data. See sparse (p. 248) for examples.
Uniform matrix Example commands for plotting uniform matrix data:
splot 'file' matrix using 1:2:3
splot 'file' binary general using 1:2:3# text input# binary input

In a uniform grid matrix the z-values are read in a row at a time, i. e.,z11 z12 z13 z14 ...
z21 z22 z23 z24 ...
z31 z32 z33 z34 ...

and so forth.
For text input, if the first row contains column labels rather than data, use the additional keyword columnheaders. Similarly if the first field in each row contains a label rather than data, use the additional keyword
rowheaders. Here is an example that uses both:$DATA << EOD
xxx A
B
C
D
aa z11 z12 z13 z14
bb z21 z22 z23 z24
cc z31 z32 z33 z34
EODplot $DATA matrix columnheaders rowheaders with image

For text input, a blank line or comment line ends the matrix, and starts a new data block. You can selectamong the data blocks in a file by the index option to the splot command, as usual. The columnheaders
option, if present, is applied only to the first data block.
Nonuniform matrix The first row of input data contains the y coordinates. The first column of input
data contains the x coordinates. For binary input data, the first field of the first row must contain thenumber of columns. (This number is ignored for text input).
Example commands for plotting non-uniform matrix data:
splot 'file' nonuniform matrix using 1:2:3
splot 'file' binary matrix using 1:2:3# text input# binary input

Thus the data organization for non-uniform matrix input is<N+1> <x0><x1><x2> ... <xN><y0> <z0,0> <z0,1> <z0,2> ... <z0,N><y1> <z1,0> <z1,1> <z1,2> ... <z1,N>
:
:
:
:
...
:

which is then converted into triplets:<x0> <y0> <z0,0><x0> <y1> <z0,1><x0> <y2> <z0,2>:::<x0> <yN> <z0,N><x1> <y0> <z1,0><x1> <y1> <z1,1>:::

These triplets are then converted into gnuplot iso-curves and then gnuplot proceeds in the usual manner
to do the rest of the plotting.

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Sparse matrix

Syntax:sparse matrix=(cols,rows) origin=(x0,y0) dx=<delx> dy=<dely>\\The sparse matrix variant defines a uniform grid as part of the plot or splot command line. The grid is
initially empty. Any number of individual points are then read from the input file, one per line, and assigned
to the nearest grid point. I.e. a data linex y valueis evaluated asi = (x - x0) / delxj = (y - y0) / delymatrix[i,j] = value

The size of the matrix is required. origin (optional) defaults to origin=(0,0). dx (optional) defaults todx=1. dy (optional) defaults to dy=dx.
The intended use of this variant is to generate heatmaps from unordered, possibly incomplete, data using
the image, rgbimage, or rgbalpha plot styles. The example below generates a distance matrix in the formof a 4x4 heatmap with only the upper triangle elements present:$DATA << EOD
1 1 101 2 201 3 301 4 402 2 102 3 502 4 603 3 103 4 204 4 10EOD
plot $DATA sparse matrix=(4,4) origin=(1,1) with image

Atlantis

FiniasYs

ErewhonErewhon

Fare
⋎60.
⋎50.

Ys

⋎40.
⋎30.

Finias⋎20.
Atlantis

Intercity Transit⋎10.

Every The every keyword has special meaning when used with matrix data. Rather than applying toblocks of single points, it applies to rows and column values. Note that matrix rows and columns are indexed
starting from 0, so the row with index N is the (N+1)th row. Syntax:
plot 'file' matrix every {<column_incr>}{:{<row_incr>}{:{<start_column>}{:{<start_row>}{:{<end_column>}{:<end_row>}}}}}

Examples:plot 'file' matrix every :::N::N# plot all values in row with index N
plot 'file' matrix every ::3::7# plot columns 3 to 7 for all rows
plot 'file' matrix every ::3:0:7:4 # submatrix bounded by [3,0] and [7,4]

Examples A collection of matrix and vector manipulation routines (in C) is provided in binary.c. The
routine to write binary data is
int fwrite_matrix(file,m,nrl,nrl,ncl,nch,row_title,column_title)

An example of using these routines is provided in the file bf test.c, which generates binary files for the demo
file demo/binary.dem.
Usage in plot:gnuplot 6.0

249

plot 'a.dat' matrix
plot 'a.dat' matrix using 1:3
plot 'a.gpbin' {matrix} binary using 1:3

will plot rows of the matrix, while using 2:3 will plot matrix columns, and using 1:2 the point coordinates(rather useless). Applying the every option you can specify explicit rows and columns.
Example – rescale axes of a matrix in a text file:
splot `a.dat` matrix using (1+$1):(1+$2*10):3

Example – plot the 3rd row of a matrix in a text file:plot 'a.dat' matrix using 1:3 every 1:999:1:2(rows are enumerated from 0, thus 2 instead of 3).
Gnuplot can read matrix binary files by use of the option binary appearing without keyword qualifications
unique to general binary, i.e., array, record, format, or filetype. Other general binary keywords fortranslation should also apply to matrix binary. (See binary general (p. 121) for more details.)
Example datafile
A simple example of plotting a 3D data file issplot 'datafile.dat'

where the file "datafile.dat" might contain:# The valley of the Gnu.
0 0 100 1 100 2 101 0 101 1 5
1 2 102 0 102 1 1
2 2 103 0 103 1 0
3 2 10Note that "datafile.dat" defines a 4 by 3 grid ( 4 rows of 3 points each ). Rows (blocks) are separated byblank records.
Note also that the x value is held constant within each dataline. If you instead keep y constant, and plot
with hidden-line removal enabled, you will find that the surface is drawn ’inside-out’.
Actually for grid data it is not necessary to keep the x values constant within a block, nor is it necessary tokeep the same sequence of y values. gnuplot requires only that the number of points be the same for eachblock. However since the surface mesh, from which contours are derived, connects sequentially corresponding
points, the effect of an irregular grid on a surface plot is unpredictable and should be examined on a caseby-case basis.

Grid data
The 3D routines are designed for points in a grid format, with one sample, datapoint, at each mesh intersection; the datapoints may originate from either evaluating a function, see set isosamples (p. 174), or
reading a datafile, see splot datafile (p. 246). The term "isoline" is applied to the mesh lines for both
functions and data. Note that the mesh need not be rectangular in x and y, as it may be parameterized inu and v, see set isosamples (p. 174).

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However, gnuplot does not require that format. In the case of functions, ’samples’ need not be equal to’isosamples’, i.e., not every x-isoline sample need intersect a y-isoline. In the case of data files, if there arean equal number of scattered data points in each block, then "isolines" will connect the points in a block,and "cross-isolines" will connect the corresponding points in each block to generate a "surface". In either
case, contour and hidden3d modes may give different plots than if the points were in the intended format.
Scattered data can be fit to a grid before plotting. See set dgrid3d (p. 164).
The contour code tests for z intensity along a line between a point on a y-isoline and the corresponding pointin the next y-isoline. Thus a splot contour of a surface with samples on the x-isolines that do not coincidewith a y-isoline intersection will ignore such samples. Try:
set xrange [-pi/2:pi/2]; set yrange [-pi/2:pi/2]
set style function lp
set contour
set isosamples 10,10; set samples 10,10;
splot cos(x)*cos(y)set samples 4,10; replot
set samples 10,4; replot

Splot surfaces
splot can display a surface as a collection of points, or by connecting those points. As with plot, the points
may be read from a data file or result from evaluation of a function at specified intervals, see set isosamples(p. 174). The surface may be approximated by connecting the points with straight line segments, see set
surface (p. 222), in which case the surface can be made opaque with set hidden3d. The orientation fromwhich the 3d surface is viewed can be changed with set view.
Additionally, for points in a grid format, splot can interpolate points having a common amplitude (see set
contour (p. 160)) and can then connect those new points to display contour lines, either directly withstraight-line segments or smoothed lines (see set cntrparam (p. 157)). Functions are already evaluatedin a grid format, determined by set isosamples and set samples, while file data must either be in a gridformat, as described in data-file, or be used to generate a grid (see set dgrid3d (p. 164)).
Contour lines may be displayed either on the surface or projected onto the base. The base projections of
the contour lines may be written to a file, and then read with plot, to take advantage of plot’s additional
formatting capabilities.

Voxel-grid
Syntax:splot $voxelgridname with {dots|points} {above <threshold>} ...
splot $voxelgridname with isosurface {level <threshold>} ...

Voxel data can be plotted with dots or points marking individual voxels whose value is above the specified
threshold value (default threshold = 0). Color/pointtype/linewidth properties can be appended as usual.
At many view angles the voxel grid points will occlude each other or create Moiré artifacts on the display.
These effects can be avoided by introducing jitter so that the displayed dot or point is displaced randomly
from the true voxel grid coordinate. See set jitter (p. 175).
Dense voxel grids can be down-sampled by using the pointinterval property (pi for short) to reduce thenumber of points drawn.
splot $vgrid with points pointtype 6 pointinterval 2

with isosurface will create a tessellated surface in 3D enclosing all voxels with value greater than therequested threshold. The surface placement is adjusted by linear interpolation to pass through the thresholdvalue itself.
See set vgrid (p. 228), vfill (p. 255). See demos vplot.dem, isosurface.dem.

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Stats (Statistical Summary)Syntax:stats {<ranges>} 'filename' {matrix | using N{:M}} {name 'prefix'} {{no}output}
stats $voxelgridname {name 'prefix'}This command prepares a statistical summary of the data in one or two columns of a file. The using specifier
is interpreted in the same way as for plot commands. See plot (p. 120) for details on the index (p. 130),
every (p. 126), and using (p. 135) directives. Data points are filtered against both xrange and yrange
before analysis. See set xrange (p. 233). The summary is printed to the screen by default. Output canbe redirected to a file by prior use of the command set print, or suppressed altogether using the nooutput
option.
If the file cannot be found or cannot be read, a non-fatal warning is issued. This can be used to test for the
existence of a file without generating a program error. See stats test (p. 252).
In addition to printed output, the program stores the individual statistics into three sets of variables. The
first set of variables reports how the data is laid out in the file. The array of column headers is generated
only if option set datafile columnheaders is in effect:
STATS_records
STATS_outofrange
STATS_invalid
STATS_blank
STATS_blocks
STATS_columns
STATS_column_header

N

total number N of in-range data records
number of records filtered out by range limits
number of invalid/incomplete/missing records
number of blank lines in the filenumber of indexable blocks of data in the filenumber of data columns in the first row of dataarray of strings holding column headers foundThe second set reports properties of the in-range data from a single column. This column is treated as y. If
the y axis is autoscaled then no range limits are applied. Otherwise only values in the range [ymin:ymax]
are considered.
If two columns are analysed jointly by a single stats command, the suffix " x" or " y" is appended to eachvariable name. I.e. STATS min x is the minimum value found in the first column, while STATS min y is theminimum value found in the second column. In this case points are filtered by testing against both xrange
and yrange.
STATS_min
STATS_max
STATS_index_min
STATS_index_max
STATS_meanȳ =STATS_stddev

σy =STATS_ssd
STATS_lo_quartile
STATS_median
STATS_up_quartile
STATS_sum
STATS_sumsq
STATS_skewness
STATS_kurtosis
STATS_adev
STATS_mean_err
STATS_stddev_err
STATS_skewness_err
STATS_kurtosis_err

sy =min(y)
max(y)
i | yi = min(y)i|Pyi = max(y)
1
y
N
q P
2
1
(y − ȳ)qN P
21(y − ȳ)
N −1

P
P y2
yP
1
3
N σ 3 P (y − ȳ)
1(y − ȳ)4
4
N σP
1
N √|y − ȳ|
σy /√Nσpy / 2N
p6/N
24/N

minimum value of in-range data points
maximum value of in-range data points
index i for which data[i] == STATS min
index i for which data[i] == STATS max
mean value of the in-range data points
population standard deviation of the in-range data
sample standard deviation of the in-range data
value of the lower (1st) quartile boundary
median value
value of the upper (3rd) quartile boundarysum
sum of squares
skewness of the in-range data points
kurtosis of the in-range data points
mean absolute deviation of the in-range data
standard error of the mean value
standard error of the standard deviation
standard error of the skewness
standard error of the kurtosis

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The third set of variables is only relevant to analysis of two data columns.
STATS_correlation
STATS_slope
STATS_slope_err
STATS_intercept
STATS_intercept_err
STATS_sumxy
STATS_pos_min_y
STATS_pos_max_ysample correlation coefficient between x and y values
A corresponding to a linear fit y = Ax + B
uncertainty of A
B corresponding to a linear fit y = Ax + B
uncertainty of B
sum of x*yx coordinate of a point with minimum y value
x coordinate of a point with maximum y value

Keyword matrix indicates that the input consists of a matrix (see matrix (p. 246)); the usual statistics are
generated by considering all matrix elements. The matrix dimensions are saved in variables STATS size x
and STATS size y.
STATS_size_x
STATS_size_ynumber of matrix columns
number of matrix rows

The index reported in STATS index xxx corresponds to the value of pseudo-column 0 ($0) in plot commands.
I.e. the first point has index 0, the last point has index N-1.
Data values are sorted to find the median and quartile boundaries. If the total number of points N is odd,
then the median value is taken as the value of data point (N+1)/2. If N is even, then the median is reported
as the mean value of points N/2 and (N+2)/2. Equivalent treatment is used for the quartile boundaries.
For an example of using the stats command to annotate a subsequent plot, see stats.dem.
The stats command in this version of gnuplot can handle log-scaled data, but not the content of time/datefields (set xdata time or set ydata time). This restriction may be relaxed in a future version.

Name
It may be convenient to track the statistics from more than one file or data column in parallel. The nameoption causes the default prefix "STATS" to be replaced by a user-specified string. For example, the meanvalue of column 2 data from two different files could be compared bystats "file1.dat" using 2 name "A"stats "file2.dat" using 2 name "B"
if (A_mean < B_mean) {...}

Instead of providing a string constant as the name, the keyword columnheader or function columnheader(N) can be used to generate the name from whatever string is found in that column in the first row
of the data file:
do for [COL=5:8] { stats 'datafile' using COL name columnheader }Test for existence of a file
Trying to plot a nonexistent or unreadable file will generate an error that halts the progress of a script or
iteration. The stats command can be used to avoid this as in the example below
do for [i=first:last] {filename = sprintf("file%02d.dat", i)stats filename nooutput
if (GPVAL_ERRNO) {print GPVAL_ERRMSG
continue}
plot filename title filename}

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Voxelgridstats $vgridname {name "prefix"}

The stats command can be used to interrogate the content of a voxel grid. It yields the same information
as show vgrid but saves it in variables accessible for use in a script.
STATS_min
STATS_max
STATS_mean
STATS_stddev
STATS_ssum
STATS_nonzero

minimum non-zero value over all voxels in grid
maximum value over all voxels in gridmean value of non-zero voxels in grid
standard deviation of non-zero voxel values
sum over all values in grid
number of non-zero voxels

SystemSyntax:system "command string"! command string
output = system("command string")
show variable GPVAL_SYSTEM

system "command" executes "command" in a subprocess by invoking the operating system’s default shell.
If called as a function, system("command") returns the character stream from the subprocess’s stdout asa string. One trailing newline is stripped from the resulting string if present. See also backquotes (p. 66).
The exit status of the subprocess is reported in variables GPVAL SYSTEM ERRNO and GPVAL SYSTEM ERRMSG. Note that if the command string invokes more than one programs, the subprocess
may return "Success" even if one of the programs produced an error. E.g. file = system("ls -1 *.plt | tail-1") will return "Success" even if there are no *.plt files because tail succeeds even if ls does not.

Test
This command graphically tests or presents terminal and palette capabilities.
Syntax:test {terminal | palette}

test or test terminal creates a display of line and point styles and other useful things supported by theterminal you are currently using.
test palette plots profiles of R(z),G(z),B(z), where 0<=z<=1. These are the RGB components of thecurrent color palette as defined by set palette. It also plots the apparent net intensity as calculated using
NTSC coefficients to map RGB onto a grayscale. The command also loads the profile values into a datablock
named $PALETTE.

ToggleSyntax:toggle {<plotno> | "plottitle" | all}This command has the same effect as left-clicking on the key entry for a plot currently displayed by aninteractive terminal (qt, wxt, x11). If the plot is showing, it is toggled off; if it is currently hidden, it istoggled on. toggle all acts on all active plots, equivalent to the hotkey "i". toggle "title" requires anexact match to the plot title. toggle "ti*" acts on the first plot whose title matches the characters before
the final ’*’. If the current terminal is not interactive, the toggle command has no effect.

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gnuplot 6.0

Undefine
Clear one or more previously defined user variables. This is useful in order to reset the state of a script
containing an initialization test.
A variable name can contain the wildcard character * as last character. If the wildcard character is found,
all variables with names that begin with the prefix preceding the wildcard will be removed. This is useful toremove several variables sharing a common prefix. Note that the wildcard character is only allowed at theend of the variable name! Specifying the wildcard character as sole argument to undefine has no effect.
Example:undefine foo foo1 foo2
if (!exists("foo")) load "initialize.gp"
bar = 1; bar1 = 2; bar2 = 3
undefine bar*# removes all three variables

Unset
Options set using the set command may be returned to their default state by the corresponding unset
command. The unset command may contain an optional iteration clause. See plot for (p. 141).
Examples:set xtics mirror rotate by -45 0,10,100...
unset xtics# Unset labels numbered between 100 and 200
unset for [i=100:200] label iLinetype
Syntax:unset linetype N

Remove all characteristics previously associated with a single linetype. Subsequent use of this linetype will
use whatever characteristics and color that is native to the current terminal type (i.e. the default linetypes
properties available in gnuplot versions prior to 4.6).

Monochrome
Switches the active set of linetypes from monochrome to color. Equivalent to set color.

OutputBecause some terminal types allow multiple plots to be written into a single output file, the output file is
not automatically closed after plotting. In order to print or otherwise use the file safely, it should first be
closed explicitly by using unset output or by using set output to close the previous file and then open a
new one.

Terminal
The default terminal that is active at the time of program entry depends on the system platform, gnuplot
build options, and the environmental variable GNUTERM. Whatever this default may be, gnuplot saves it
to internal variable GNUTERM. The unset terminal command restores the initial terminal type. It isequivalent to set terminal GNUTERM. However if the string in GNUTERM contains terminal optionsin addition to the bare terminal name, you may want to instead use set terminal @GNUTERM.

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255

Warnings
set warnings
unset warnings

Warning messages for non-fatal errors are normally printed to stderr after echoing the file name, line number, and command line that triggered the warning. Warnings may be suppressed by the command unset
warnings. A warning may be generated on demand by the command warn "message". They remain
suppressed until explicitly reenabled by set warnings.

UpdateNote: This command is DEPRECATED. Use save fit instead.

VclearSyntax:vclear {$gridname}Resets the value of all voxels in an existing grid to zero. If no grid name is given, clears the currently active
grid.

Vfill
Syntax:vfill FILE using x:y:z:radius:(<expression>)
vgfill FILE using x:y:z:radius:(<expression>)

The vfill command acts analogously to a plot command except that instead of creating a plot it modifies
voxels in the currently active voxel grid. For each point read from the input file, the voxel containing thatpoint and also all other voxels within a sphere of given radius centered about (x,y,z) are incremented asfollows:• user variable VoxelDistance is set to the distance from (x,y,z) to that voxel’s origin in user coordinates(vx,vy,vz).
• user variable GridDistance is set to the distance from (x,y,z) to that voxel’s origin in grid coordinates.
• The expression provided in the 5th using specifier is evaluated. This expression can use the new valueof VoxelDistance and/or GridDistance.
• voxel(vx,vy,vz) += result of evaluating <expression>
Examples:vfill "file.dat" using 1:2:3:(3.0):(1.0)

This command adds 1 to the value of every voxel within a sphere of radius 3.0 around each point in file.dat.
The number of voxels that this sphere impinges on depends on the grid spacing in user coordinates, which
may be different along the x, y, and z directions.
vgfill "file.dat" using 1:2:3:(2):(1.0)

This command adds 1 to the value of voxels within a 5x5x5 cube of voxels centered on the current point.
The radius "2" is interpreted as extending exactly 2 voxels in either direction along x, 2 voxels in either
direction along y, etc, regardless of the relative scaling of user coordinates along those axes.
Example:256

gnuplot 6.0
vfill "file.dat" using 1:2:3:4:(VoxelDistance < 1 ? 1 : 1/VoxelDistance)

This command modifies all voxels in a sphere whose radius is determined for each point by the content ofcolumn 4. The increment added to a voxel decreases with its distance from the data point.
Note that vfill and vgfill always increments existing values in the current voxel grid. To reset a single voxel
to zero, use voxel(x,y,z) = 0. To reset the entire grid to zero, use vclear.

Warn
Syntax:warn "message"

The warn command is essentially the same as printerr except that it prepends the current filename orfunction block name and the current line number before printing the requested message to stderr. Unlike
printerr the output from warn is suppressed by unset warnings.

While
Syntax:while (<expr>) {<commands>}

Execute a block of commands repeatedly so long as <expr> evaluates to a non-zero value. This commandcannot be mixed with old-style (un-bracketed) if/else statements. See also do (p. 104), continue (p. 104),
break (p. 102).

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257

Part IV

Terminal types
Complete list of terminals
Gnuplot supports a large number of output formats. These are selected by choosing an appropriate terminal
type, possibly with additional modifying options. See set terminal (p. 223).
This document may describe terminal types that are not available to you because they were not configured
or installed on your system. Terminals marked legacy are not built by default in recent gnuplot versions
and may not actually work. To see a list of terminals available in a particular gnuplot session, type ’set
terminal’ with no modifiers.
Several terminals are designed for use with TeX/LaTeX document preparation. A summary of TeX-friendly
terminals is available here: http://www.gnuplot.info/docs/latex demo.pdf

Aifm
NOTE: Legacy terminal, originally written for Adobe Illustrator 3.0+. Since Adobe Illustrator understands PostScript level 1 commands directly, you should use set terminal post level1 instead.
Syntax:set terminal aifm {color|monochrome} {"<fontname>"} {<fontsize>}

Aqua
This terminal relies on AquaTerm.app for display on MacOS.
Syntax:set terminal aqua {<n>} {title "<wintitle>"} {size <x> <y>}{font "<fontname>{,<fontsize>}"}{linewidth <lw>}"}{{no}enhanced} {solid|dashed} {dl <dashlength>}}where <n> is the number of the window to draw in (default is 0), <wintitle> is the name shown in the titlebar (default "Figure <n>"), <x> <y> is the size of the plot (default is 846x594 pt = 11.75x8.25 in).
Use <fontname> to specify the font (default is "Times-Roman"), and <fontsize> to specify the font size
(default is 14.0 pt).
The aqua terminal supports enhanced text mode (see enhanced (p. 34)), except for overprint. Font support
is limited to the fonts available on the system. Character encoding can be selected by set encoding andcurrently supports iso latin 1, iso latin 2, cp1250, and UTF8 (default).
Lines can be drawn either solid or dashed, (default is solid) and the dash spacing can be modified by<dashlength> which is a multiplier > 0.

Be
The be terminal type is present if gnuplot is built for the beos operating system and for use with X servers.
It is selected at program startup if the DISPLAY environment variable is set, if the TERM environment
variable is set to xterm, or if the -display command line option is used.
Syntax:set terminal be {reset} {<n>}258gnuplot 6.0

Multiple plot windows are supported: set terminal be <n> directs the output to plot window number n.
If n>0, the terminal number will be appended to the window title and the icon will be labeled gplt <n>.
The active window may distinguished by a change in cursor (from default to crosshair.)
Plot windows remain open even when the gnuplot driver is changed to a different device. A plot window
can be closed by pressing the letter q while that window has input focus, or by choosing close from awindow manager menu. All plot windows can be closed by specifying reset, which actually terminates the
subprocess which maintains the windows (unless -persist was specified).
Plot windows will automatically be closed at the end of the session unless the -persist option was given.
The size or aspect ratio of a plot may be changed by resizing the gnuplot window.
Linewidths and pointsizes may be changed from within gnuplot with set linestyle.
For terminal type be, gnuplot accepts (when initialized) the standard X Toolkit options and resources suchas geometry, font, and name from the command line arguments or a configuration file. See the X(1) man
page (or its equivalent) for a description of such options.
A number of other gnuplot options are available for the be terminal. These may be specified either as
command-line options when gnuplot is invoked or as resources in the configuration file ".Xdefaults". They
are set upon initialization and cannot be altered during a gnuplot session.
Command-line options
In addition to the X Toolkit options, the following options may be specified on the command line whenstarting gnuplot or as resources in your ".Xdefaults" file:‘-mono‘‘-gray‘‘-clear‘‘-raise‘‘-noraise‘‘-persist‘forces monochrome rendering on color displays.
requests grayscale rendering on grayscale or color displays.
(Grayscale displays receive monochrome rendering by default.)
requests that the window be cleared momentarily before a
new plot is displayed.
raises plot window after each plot.
does not raise plot window after each plot.
plots windows survive after main gnuplot program exits.

The options are shown above in their command-line syntax. When entered as resources in ".Xdefaults",
they require a different syntax.
Example:gnuplot*gray: on

gnuplot also provides a command line option (-pointsize <v>) and a resource, gnuplot*pointsize: <v>,
to control the size of points plotted with the points plotting style. The value v is a real number (greaterthan 0 and less than or equal to ten) used as a scaling factor for point sizes. For example, -pointsize 2 uses
points twice the default size, and -pointsize 0.5 uses points half the normal size.
Monochrome options
For monochrome displays, gnuplot does not honor foreground or background colors. The default is blackon-white. -rv or gnuplot*reverseVideo: on requests white-on-black.
Color resources
For color displays, gnuplot honors the following resources (shown here with their default values) or thegreyscale resources. The values may be color names as listed in the BE rgb.txt file on your system, hexadecimal RGB color specifications (see BE documentation), or a color name followed by a comma and an
intensity value from 0 to 1. For example, blue, 0.5 means a half intensity blue.

gnuplot 6.0259

gnuplot*background: whitegnuplot*textColor: black
gnuplot*borderColor: black
gnuplot*axisColor: black
gnuplot*line1Color: red
gnuplot*line2Color: green
gnuplot*line3Color: blue
gnuplot*line4Color: magenta
gnuplot*line5Color: cyan
gnuplot*line6Color: sienna
gnuplot*line7Color: orange
gnuplot*line8Color: coral
The command-line syntax for these is, for example,
Example:gnuplot -background coral

Grayscale resources
When -gray is selected, gnuplot honors the following resources for grayscale or color displays (shown herewith their default values). Note that the default background is black.
gnuplot*background: black
gnuplot*textGray: whitegnuplot*borderGray: gray50
gnuplot*axisGray: gray50
gnuplot*line1Gray: gray100
gnuplot*line2Gray: gray60
gnuplot*line3Gray: gray80
gnuplot*line4Gray: gray40
gnuplot*line5Gray: gray90
gnuplot*line6Gray: gray50
gnuplot*line7Gray: gray70
gnuplot*line8Gray: gray30
Line resources
gnuplot honors the following resources for setting the width (in pixels) of plot lines (shown here with theirdefault values.) 0 or 1 means a minimal width line of 1 pixel width. A value of 2 or 3 may improve theappearance of some plots.
gnuplot*borderWidth: 2
gnuplot*axisWidth: 0
gnuplot*line1Width: 0
gnuplot*line2Width: 0
gnuplot*line3Width: 0
gnuplot*line4Width: 0
gnuplot*line5Width: 0
gnuplot*line6Width: 0
gnuplot*line7Width: 0
gnuplot*line8Width: 0

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gnuplot honors the following resources for setting the dash style used for plotting lines. 0 means a solidline. A two-digit number jk (j and k are >= 1 and <= 9) means a dashed line with a repeated pattern ofj pixels on followed by k pixels off. For example, ’16’ is a "dotted" line with one pixel on followed by six
pixels off. More elaborate on/off patterns can be specified with a four-digit value. For example, ’4441’ is fouron, four off, four on, one off. The default values shown below are for monochrome displays or monochrome
rendering on color or grayscale displays. For color displays, the default for each is 0 (solid line) except for
axisDashes which defaults to a ’16’ dotted line.
gnuplot*borderDashes: 0
gnuplot*axisDashes: 16
gnuplot*line1Dashes: 0
gnuplot*line2Dashes: 42
gnuplot*line3Dashes: 13
gnuplot*line4Dashes: 44
gnuplot*line5Dashes: 15
gnuplot*line6Dashes: 4441
gnuplot*line7Dashes: 42
gnuplot*line8Dashes: 13

Block
The block terminal generates pseudo-graphic output using Unicode block or Braille characters to increase
the resolution. It is an alternative for terminal graphics. It requires a UTF-8 capable terminal or viewer.
Drawing uses the internal bitmap code. Text is printed on top of the graphics using the dumb terminal’s
routines.
Syntax:set term block{dot | half | quadrants | sextants | octants | braille |sextpua | octpua}{{no}enhanced}{size <x>, <y>}{mono | ansi | ansi256 | ansirgb}{{no}optimize}{[no]attributes}{numpoints | charpoints | gppoints}{[no]animate}size sets the terminal size in character cells.
dot, half, quadrants, sextants, or braille select the character set used for the creation of pseudo-graphics.
dot uses simple dots, while half uses half-block characters. quadrants uses block characters which yielddouble resolution in both directions. sextants uses 2x3 block characters, and braille uses Braille characterswhich give a 2x4 pseudo-resolution. octants uses the proposed 2x4 block characters. sextpua and octpua
use the sextants or octants, respectively, in the CreativeKorp private-use-area (PUA) which might be only
available with their FairfaxHD and KreativeSquare fonts.
Note that the 2x3 block characters (’sextants’) have only been included in Unicode 13. Hence, font support
is still limited. Similarly for Braille. Usable fonts include e.g. unscii, IBM 3270, GNU Unifont, DejaVu
Sans, and, FairfaxHD. 2x4 block characters (’octants’) have only been accepted for inclusion in a future
Unicode standard in 2022 and are available in the FairfaxHD font.
The ansi, ansi256, and ansirgb options will include escape sequences in the output to output colors. Notethat these might not be handled by your terminal. Default is mono. See terminal dumb (p. 270) for alist of escape sequences.
The attributes option enables bold and italic text on terminals or emulators that support these escapesequences, see terminal dumb (p. 270).

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Using block characters increases the pseudo-resolution of the bitmap. But this is not the case for the color.
Multiple ’pixels’ necessarily share the same color. This is dealt with by averaging the color of all pixels ina charcell. With optimize, the terminal tries to improve by setting both, the background and foregroundcolors. This trick works perfectly for the half mode, but is increasingly difficult for quadrants, sextants,
or octants. For braille this cannot be used.
gppoints draws point symbols using graphics commands. Due to the low resolution of the terminal, this ismostly viable for braille or octant mode, and probably most useful for error bars. charpoints uses Unicode
symbol characters instead. Note that these are also always drawn on top of the graphics. numpoints uses
super- and subscript numerals to double the vertical resolution. For sextants, points in the character cell’scenter position have to be drawn using ordinary numerals, though. Note that the bitmap resolution is still
different and lines and symbols in general do not align exactly when using charpoints or numpoints.
The animate option resets the cursor position to the top left of the plot after every plot so that successiveplots overwrite the same area on the screen rather than having earlier plots scroll off the top. This may bedesirable in order to create an in-place animation.

Caca[EXPERIMENTAL] The caca terminal is a mostly-for-fun output mode that uses libcaca to plot using ascii
characters. In contrast to the dumb terminal it includes support for color, box fill, images, rotated text,
filled polygons, and mouse interaction.
Syntax:set terminal caca {{driver | format} {default | <driver> | list}}{color | monochrome}{{no}inverted}{enhanced | noenhanced}{background <rgb color>}{title "<plot window title>"}{size <width>,<height>}{charset ascii|blocks|unicode}

The driver option selects the libcaca display driver or export format. Use default is to let libcaca choose
the platform default display driver. The default driver can be changed by setting the environment variable
CACA DRIVER before starting gnuplot. Use set term caca driver list to print a list of supported output
modes.
The color and monochrome options select colored or mono output. Note that this also changes line
symbols. Use the inverted option if you prefer a black background over the default white. This alsochanges the color of black default linetypes to white.
Enhanced text support can be activated using the enhanced option, see enhanced text (p. 34).
The title of the output window can be changed with the title option, if supported by the libcaca driver.
The size option selects the size of the canvas in characters. The default is 80 by 25. If supported by thebackend, the canvas size will be automatically adjusted to the current window/terminal size. The default
size of the "x11" and "gl" window can be controlled via the CACA GEOMETRY environment variable.
The geometry of the window of the "win32" driver can be controlled and permanently changed via the app
menu.
The charset option selects the character set used for lines, points, filling of polygons and boxes and ditheringof images. Note that some backend/terminal/font combinations might not support some characters of theblocks or unicode character set. On Windows it is recommend to use a non-raster font such as "Lucida
Console" or "Consolas".
The caca terminal supports mouse interaction. Please beware that some backends of libcaca (e.g. slang,ncurses) only update the mouse position on mouse clicks. Modifier keys (ctrl, alt, shift) are not supported
by libcaca and are thus unavailable.
The default encoding of the caca terminal is utf8. It also supports the cp437 encoding.

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The number of colors supported by libcaca backends differs. Most backends support 16 foreground and 16
background colors only, whereas e.g. the "x11" backend supports truecolor.
Depending on the terminal and libcaca backend, only 8 different background colors might be supported.
Bright colors (with the most most significant bit of the background color set) are then interpreted as indicatorfor blinking text. Try using background rgb "gray" in that case.
See also the libcaca web site at http://caca.zoy.org/wiki/libcaca
and libcaca environment variables http://caca.zoy.org/doxygen/libcaca/libcaca-env.html
Caca limitations and bugs
The caca terminal has known bugs and limitations:Unicode support depends on the driver and the terminal. The "x11" backend supports unicode since libcaca
version 0.99.beta17. Due to a bug in libcaca <0.99.beta20, the "slang" driver does not support unicode.
Note that libcaca <0.99.beta19 contains a bug which results in an endless loop if you supply illegal 8bit
sequences.
Bright background colors may cause blinking.
Modifier keys are not supported for mousing, see term caca (p. 261).
Rotated enhanced text, and transparency are not supported. The size option is not considered for on-screen
display.
In order to correctly draw the key box, use
set key width 1 height 1

Alignment of enhanced text is wrong if it contains utf8 characters. Resizing of Windows console window
does not work correctly due to a bug in libcaca. Closing the terminal window by clicking the "X" on thetitle line will terminate wgnuplot. Press "q" to close the window.

Cairolatex
The cairolatex terminal device generates encapsulated PostScript (*.eps), PDF, or PNG output using thecairo and pango support libraries and uses LaTeX for text output using the same routines as the epslatex
terminal.
Syntax:set terminal cairolatex{eps | pdf | png}
{standalone | input}{blacktext | colortext | colourtext}{header <header> | noheader}{mono|color}{{no}transparent} {{no}crop} {background <rgbcolor>}{font <font>} {fontscale <scale>}{linewidth <lw>} {rounded|butt|square} {dashlength <dl>}{size <XX>{unit},<YY>{unit}}{resolution <dpi>}

The cairolatex terminal prints a plot like terminal epscairo or terminal pdfcairo but transfers the texts
to LaTeX instead of including them in the graph. For reference of options not explained here see pdfcairo(p. 285).
eps, pdf, or png select the type of graphics output. Use eps with latex/dvips and pdf for pdflatex. If
your plot has a huge number of points use png to keep the filesize down. When using the png option, theterminal accepts an extra option resolution to control the pixel density of the resulting PNG. The argumentof resolution is an integer with the implied unit of DPI.
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The cairolatex driver offers a special way of controlling text positioning: (a) If any text string begins with’{’, you also need to include a ’}’ at the end of the text, and the whole text will be centered both horizontallyand vertically by LaTeX. (b) If the text string begins with ’[’, you need to continue it with: a position
specification (up to two out of t,b,l,r,c), ’]{’, the text itself, and finally, ’}’. The text itself may be anything
LaTeX can typeset as an LR-box. \rule{}{}’s may help for best positioning. See also the documentation forthe pslatex (p. 293) terminal driver. To create multiline labels, use \shortstack, for example
set ylabel '[r]{\shortstack{first line \\ second line}}'

The back option of set label commands is handled slightly different than in other terminals. Labels using’back’ are printed behind all other elements of the plot while labels using ’front’ are printed above everythingelse.
The driver produces two different files, one for the eps, pdf, or png part of the figure and one for the LaTeX
part. The name of the LaTeX file is taken from the set output command. The name of the eps/pdf/png
file is derived by replacing the file extension (normally ’.tex’) with ’.eps’/’.pdf’/’.png’ instead. There is no
LaTeX output if no output file is given! Remember to close the output file before next plot unless in
multiplot mode.
In your LaTeX documents use ’\input{filename}’ to include the figure. The ’.eps’/’.pdf’/’.png’ file is included by the command \includegraphics{...}, so you must also include \usepackage{graphicx} in the LaTeX
preamble. If you want to use coloured text (option colourtext) you also have to include \usepackage{color}in the LaTeX preamble.
The behaviour concerning font selection depends on the header mode. In all cases, the given font size is used
for the calculation of proper spacing. When not using the standalone mode the actual LaTeX font and fontsize at the point of inclusion is taken, so use LaTeX commands for changing fonts. If you use e.g. 12pt as
font size for your LaTeX document, use ’", 12"’ as options. The font name is ignored. If using standalone
the given font and font size are used, see below for a detailed description.
If text is printed coloured is controlled by the TeX booleans \ifGPcolor and \ifGPblacktext. Only if\ifGPcolor is true and \ifGPblacktext is false, text is printed coloured. You may either change them in
the generated TeX file or provide them globally in your TeX file, for example by using\newif\ifGPblacktext\GPblacktexttrue

in the preamble of your document. The local assignment is only done if no global value is given.
When using the cairolatex terminal give the name of the TeX file in the set output command including thefile extension (normally ".tex"). The graph filename is generated by replacing the extension.
If using the standalone mode a complete LaTeX header is added to the LaTeX file; and "-inc" is added
to the filename of the gaph file. The standalone mode generates a TeX file that produces output with thecorrect size when using dvips, pdfTeX, or VTeX. The default, input, generates a file that has to be included
into a LaTeX document using the \input command.
If a font other than "" or "default" is given it is interpreted as LaTeX font name. It contains up to three parts,
separated by a comma: ’fontname,fontseries,fontshape’. If the default fontshape or fontseries are requested,
they can be omitted. Thus, the real syntax for the fontname is ’{fontname}{,fontseries}{,fontshape}’. The
naming convention for all parts is given by the LaTeX font scheme. The fontname is 3 to 4 characterslong and is built as follows: One character for the font vendor, two characters for the name of the font, andoptionally one additional character for special fonts, e.g., ’j’ for fonts with old-style numerals or ’x’ for expert
fonts. The names of many fonts is described in http://www.tug.org/fontname/fontname.pdf
For example, ’cmr’ stands for Computer Modern Roman, ’ptm’ for Times-Roman, and ’phv’ for Helvetica.
The font series denotes the thickness of the glyphs, in most cases ’m’ for normal ("medium") and ’bx’ or’b’ for bold fonts. The font shape is ’n’ for upright, ’it’ for italics, ’sl’ for slanted, or ’sc’ for small caps, ingeneral. Some fonts may provide different font series or shapes.
Examples:Use Times-Roman boldface (with the same shape as in the surrounding text):
set terminal cairolatex font 'ptm,bx'

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Use Helvetica, boldface, italics:
set terminal cairolatex font 'phv,bx,it'

Continue to use the surrounding font in slanted shape:
set terminal cairolatex font ',,sl'Use small capitals:
set terminal cairolatex font ',,sc'

By this method, only text fonts are changed. If you also want to change the math fonts you have to use the"gnuplot.cfg" file or the header option, described below.
In standalone mode, the font size is taken from the given font size in the set terminal command. To beable to use a specified font size, a file "size<size>.clo" has to reside in the LaTeX search path. By default,
10pt, 11pt, and 12pt are supported. If the package "extsizes" is installed, 8pt, 9pt, 14pt, 17pt, and 20pt areadded.
The header option takes a string as argument. This string is written into the generated LaTeX file. If using
the standalone mode, it is written into the preamble, directly before the \begin{document} command. In
the input mode, it is placed directly after the \begingroup command to ensure that all settings are local tothe plot.
Examples:Use T1 fontencoding, change the text and math font to Times-Roman as well as the sans-serif font toHelvetica:
set terminal cairolatex standalone header \"\\usepackage[T1]{fontenc}\n\\usepackage{mathptmx}\n\\usepackage{helvet}"

Use a boldface font in the plot, not influencing the text outside the plot:
set terminal cairolatex input header "\\bfseries"

If the file "gnuplot.cfg" is found by LaTeX it is input in the preamble the LaTeX document, when using
standalone mode. It can be used for further settings, e.g., changing the document font to Times-Roman,
Helvetica, and Courier, including math fonts (handled by "mathptmx.sty"):\usepackage{mathptmx}\usepackage[scaled=0.92]{helvet}\usepackage{courier}

The file "gnuplot.cfg" is loaded before the header information given by the header command. Thus, you
can use header to overwrite some of settings performed using "gnuplot.cfg"

Canvas
The canvas terminal creates a set of javascript commands that draw onto the HTML5 canvas element.
Syntax:set terminal canvas {size <xsize>, <ysize>} {background <rgb_color>}{font {<fontname>}{,<fontsize>}} | {fsize <fontsize>}{{no}enhanced} {linewidth <lw>}{rounded | butt | square}{dashlength <dl>}{standalone {mousing} | name '<funcname>'}{jsdir 'URL/for/javascripts'}{title '<some string>'}

where <xsize> and <ysize> set the size of the plot area in pixels. The default size in standalone mode is
600 by 400 pixels. The default font size is 10.
NB: Only one font is available, the ascii portion of Hershey simplex Roman provided in the file canvastext.js.
You can replace this with the file canvasmath.js, which contains also UTF-8 encoded Hershey simplex Greek

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and math symbols. For consistency with other terminals, it is also possible to use font "name,size".
Currently the font name is ignored, but browser support for named fonts is likely to arrive eventually.
The default standalone mode creates an html page containing javascript code that renders the plot using the HTML 5 canvas element. The html page links to two required javascript files ’canvastext.js’ and’gnuplot common.js’. An additional file ’gnuplot dashedlines.js’ is needed to support dashed lines. By default
these point to local files, on unix-like systems usually in directory /usr/local/share/gnuplot/<version>/js.
See installation notes for other platforms. You can change this by using the jsdir option to specify eithera different local directory or a general URL. The latter is usually appropriate if the plot is exported forviewing on remote client machines.
All plots produced by the canvas terminal are mouseable. The additional keyword mousing causes thestandalone mode to add a mouse-tracking box underneath the plot. It also adds a link to a javascript
file ’gnuplot mouse.js’ and to a stylesheet for the mouse box ’gnuplot mouse.css’ in the same local or URL
directory as ’canvastext.js’.
The name option creates a file containing only javascript. Both the javascript function it contains and theid of the canvas element that it draws onto are taken from the following string parameter. The commands
set term canvas name 'fishplot'
set output 'fishplot.js'

will create a file containing a javascript function fishplot() that will draw onto a canvas with id=fishplot. An
html page that invokes this javascript function must also load the canvastext.js function as described above.
A minimal html file to wrap the fishplot created above might be:<html><head><script src="canvastext.js"></script><script src="gnuplot_common.js"></script></head><body onload="fishplot();"><script src="fishplot.js"></script><canvas id="fishplot" width=600 height=400><div id="err_msg">No support for HTML 5 canvas element</div></canvas></body></html>The individual plots drawn on this canvas will have names fishplot plot 1, fishplot plot 2, and so on. Thesecan be referenced by external javascript routines, for example gnuplot.toggle visibility("fishplot plot 2").

Cgm
The cgm terminal generates a Computer Graphics Metafile, Version 1. This file format is a subset of the
ANSI X3.122-1986 standard entitled "Computer Graphics - Metafile for the Storage and Transfer of Picture
Description Information".
Syntax:set terminal cgm {color | monochrome} {solid | dashed} {{no}rotate}{<mode>} {width <plot_width>} {linewidth <line_width>}{font "<fontname>,<fontsize>"}{background <rgb_color>}[deprecated]{<color0> <color1> <color2> ...}

solid draws all curves with solid lines, overriding any dashed patterns; <mode> is landscape, portrait, or
default; <plot width> is the assumed width of the plot in points; <line width> is the line width in points(default 1); <fontname> is the name of a font (see list of fonts below) <fontsize> is the size of the font inpoints (default 12).
The first six options can be in any order. Selecting default sets all options to their default values.
The mechanism of setting line colors in the set term command is deprecated. Instead you should set thebackground using a separate keyword and set the line colors using set linetype. The deprecated mechanism

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accepted colors of the form ’xrrggbb’, where x is the literal character ’x’ and ’rrggbb’ are the red, green andblue components in hex. The first color was used for the background, subsequent colors are assigned tosuccessive line types.
Examples:set terminal cgm landscape color rotate dashed width 432 \linewidth 1 'Helvetica Bold' 12# defaults
set terminal cgm linewidth 2 14 # wider lines & larger font
set terminal cgm portrait "Times Italic" 12
set terminal cgm color solid# no pesky dashes!

Cgm font
The first part of a Computer Graphics Metafile, the metafile description, includes a font table. In the picture
body, a font is designated by an index into this table. By default, this terminal generates a table with thefollowing 35 fonts, plus six more with italic replaced by oblique, or vice-versa (since at least the Microsoft
Office and Corel Draw CGM import filters treat italic and oblique as equivalent):
CGM fonts
Helvetica
Hershey/Cartographic Roman
Helvetica Bold
Hershey/Cartographic Greek
Helvetica Oblique
Hershey/Simplex Roman
Helvetica Bold Oblique Hershey/Simplex Greek
Times Roman
Hershey/Simplex Script
Times Bold
Hershey/Complex Roman
Times Italic
Hershey/Complex Greek
Times Bold Italic
Hershey/Complex Italic
Courier
Hershey/Complex Cyrillic
Courier Bold
Hershey/Duplex Roman
Courier Oblique
Hershey/Triplex Roman
Courier Bold Oblique
Hershey/Triplex Italic
SymbolHershey/Gothic German
ZapfDingbats
Hershey/Gothic English
ScriptHershey/Gothic Italian
15
Hershey/Symbol Set 1
Hershey/Symbol Set 2
Hershey/Symbol Math
The first thirteen of these fonts are required for WebCGM. The Microsoft Office CGM import filter implements the 13 standard fonts listed above, and also ’ZapfDingbats’ and ’Script’. However, the script font may
only be accessed under the name ’15’. For more on Microsoft import filter font substitutions, check its help
file which you may find here:
C:\Program Files\Microsoft Office\Office\Cgmimp32.hlp

and/or its configuration file, which you may find here:
C:\Program Files\Common Files\Microsoft Shared\Grphflt\Cgmimp32.cfg

In the set term command, you may specify a font name which does not appear in the default font table.
In that case, a new font table is constructed with the specified font as its first entry. You must ensure thatthe spelling, capitalization, and spacing of the name are appropriate for the application that will read the
CGM file. (Gnuplot and any MIL-D-28003A compliant application ignore case in font names.) If you needto add several new fonts, use several set term commands.
Example:set terminal cgm 'Old English'
set terminal cgm 'Tengwar'

gnuplot 6.0267

set terminal cgm 'Arabic'
set output 'myfile.cgm'
plot ...
set output

You cannot introduce a new font in a set label command.

Cgm fontsize
Fonts are scaled assuming the page is 6 inches wide. If the size command is used to change the aspect ratioof the page or the CGM file is converted to a different width, the resulting font sizes will be scaled up or
down accordingly. To change the assumed width, use the width option.

Cgm linewidth
The linewidth option sets the width of lines in pt. The default width is 1 pt. Scaling is affected by theactual width of the page, as discussed under the fontsize and width options.

Cgm rotate
The norotate option may be used to disable text rotation. For example, the CGM input filter for Word
for Windows 6.0c can accept rotated text, but the DRAW editor within Word cannot. If you edit a graph(for example, to label a curve), all rotated text is restored to horizontal. The Y axis label will then extend
beyond the clip boundary. With norotate, the Y axis label starts in a less attractive location, but the pagecan be edited without damage. The rotate option confirms the default behavior.

Cgm solid
The solid option may be used to disable dashed line styles in the plots. This is useful when color is enabled
and the dashing of the lines detracts from the appearance of the plot. The dashed option confirms thedefault behavior, which gives a different dash pattern to each line type.

Cgm size
Default size of a CGM plot is 32599 units wide and 23457 units high for landscape, or 23457 units wide by
32599 units high for portrait.

Cgm width
All distances in the CGM file are in abstract units. The application that reads the file determines the sizeof the final plot. By default, the width of the final plot is assumed to be 6 inches (15.24 cm). This distanceis used to calculate the correct font size, and may be changed with the width option. The keyword should
be followed by the width in points. (Here, a point is 1/72 inch, as in PostScript. This unit is known as a"big point" in TeX.) Gnuplot expressions can be used to convert from other units.
Example:set terminal cgm width 432
set terminal cgm width 6*72
set terminal cgm width 10/2.54*72# default# same as above# 10 cm wide

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Cgm nofontlist
The default font table includes the fonts recommended for WebCGM, which are compatible with the Computer Graphics Metafile input filter for Microsoft Office and Corel Draw. Another application might use
different fonts and/or different font names, which may not be documented. The nofontlist (synonym winword6) option deletes the font table from the CGM file. In this case, the reading application should use adefault table. Gnuplot will still use its own default font table to select font indices. Thus, ’Helvetica’ will
give you an index of 1, which should get you the first entry in your application’s default font table. ’Helvetica
Bold’ will give you its second entry, etc.

Context
ConTeXt is a macro package for TeX, highly integrated with Metapost (for drawing figures) and intended
for creation of high-quality PDF documents. The terminal outputs Metafun source, which can be edited
manually, but you should be able to configure most things from outside.
For an average user of ConTeXt + gnuplot module it’s recommended to refer to Using ConTeXt rather
than reading this page or to read the manual of the gnuplot module for ConTeXt.
The context terminal supports the following options:
Syntax:set term context {default}{defaultsize | size <scale> | size <xsize>{in|cm}, <ysize>{in|cm}}{input | standalone}{timestamp | notimestamp}{noheader | header "<header>"}{color | colour | monochrome}{rounded | mitered | beveled} {round | butt | squared}{dashed | solid} {dashlength | dl <dl>}{linewidth | lw <lw>}{fontscale <fontscale>}{mppoints | texpoints}{inlineimages | externalimages}{defaultfont | font "{<fontname>}{,<fontsize>}"}In non-standalone (input) graphic only parameters size to select graphic size, fontscale to scale all thelabels for a factor <fontscale> and font size, make sense, the rest is silently ignored and should be configuredin the .tex file which inputs the graphic. It’s highly recommended to set the proper fontsize if document
font differs from 12pt, so that gnuplot will know how much space to reserve for labels.
default resets all the options to their default values.
defaultsize sets the plot size to 5in,3in. size <scale> sets the plot size to <scale> times <default value>.
If two arguments are given (separated with ’,’), the first one sets the horizontal size and the second one thevertical size. Size may be given without units (in which case it means relative to the default value), with
inches (’in’) or centimeters (’cm’).
input (default) creates a graphic that can be included into another ConTeXt document. standalone adds
some lines, so that the document might be compiled as-is. You might also want to add header in that case.
Use header for any additional settings/definitions/macros that you might want to include in a standalone
graphic. noheader is the default.
notimestamp prevents printing creation time in comments (if version control is used, one may prefer not
to commit new version when only date changes).
color to make color plots is the default, but monochrome doesn’t do anything special yet. If you haveany good ideas how the behaviour should differ to suit the monochrome printers better, your suggestions arewelcome.
rounded (default), mitered and beveled control the shape of line joins. round (default), butt andsquared control the shape of line caps. See PostScript or PDF Reference Manual for explanation. For

gnuplot 6.0269

wild-behaving functions and thick lines it is better to use rounded and round to prevent sharp corners inline joins. (Some general support for this should be added to Gnuplot, so that the same options could be
set for each line (style) separately).
dashed (default) uses different dash patterns for different line types, solid draws all plots with solid lines.
dashlength or dl scales the length of the dashed-line segments by <dl>. linewidth or lw scales all
linewidths by <lw>. (lw 1 stands for 0.5bp, which is the default line width when drawing with Metapost.)
fontscale scales text labels for factor <fontscale> relative to default document font.
mppoints uses predefined point shapes, drawn in Metapost. texpoints uses easily configurable set ofsymbols, defined with ConTeXt in the following way:
\defineconversion[my own points][+,{\ss x},\mathematics{\circ}]\setupGNUPLOTterminal[context][points=tex,pointset=my own points]

inlineimages writes binary images to a string and only works in ConTeXt MKIV. externalimages writes
PNG files to disk and also works with ConTeXt MKII. Gnuplot needs to have support for PNG images built
in for this to work.
With font you can set font name and size in standalone graphics. In non-standalone (input) mode only the
font size is important to reserve enough space for text labels. The command
set term context font "myfont,ss,10"

will result in\setupbodyfont[myfont,ss,10pt]

If you additionally set fontscale to 0.8 for example, then the resulting font will be 8pt big andset label ... font "myfont,12"

will come out as 9.6pt.
It is your own responsibility to provide proper typescripts (and header), otherwise switching the font will
have no effect. For a standard font in ConTeXt MKII (pdfTeX) you could use:
set terminal context standalone header '\usetypescript[iwona][ec]' \font "iwona,ss,11"Please take a look into ConTeXt documentation, wiki or mailing list (archives) for any up-to-date information
about font usage.
Examples:set terminal context size 10cm, 5cm
set terminal context size 4in, 3in# 10cm, 5cm# 4in, 3in

For standalone (whole-page) plots with labels in UTF-8 encoding:
set terminal context standalone header '\enableregime[utf-8]'

Requirements
You need gnuplot module for ConTeXt http://ctan.org/pkg/context-gnuplot
and a recent version of ConTeXt. If you want to call gnuplot on-the-fly, you also need write18 enabled. In
most TeX distributions this can be set with shell escape=t in texmf.cnf.
See http://wiki.contextgarden.net/Gnuplot
for details about this terminal and for more exhaustive help & examples.

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Calling gnuplot from ConTeXt
The easiest way to make plots in ConTeXt documents is\usemodule[gnuplot]\starttext\title{How to draw nice plots with {\sc gnuplot}?}\startGNUPLOTscript[sin]set format y "%.1f"
plot sin(x) t '$\sin(x)$'\stopGNUPLOTscript\useGNUPLOTgraphic[sin]\stoptext

This will run gnuplot automatically and include the resulting figure in the document.

Debug
This terminal is provided to allow for the debugging of gnuplot. It is likely to be of use only for users who
are modifying the source code.

Domterm
Syntax:set terminal domterm{font "<fontname>{,<fontsize>}"} {{no}enhanced}{fontscale <multiplier>}{rounded|butt|square} {solid|dashed} {linewidth <lw>}{background <rgb_color>}{animate}

The domterm terminal device runs on the DomTerm terminal emulator including the domterm andqtdomterm programs. It supports SVG graphics embedded directly in the terminal output. See
http://domterm.org .
For information on terminal options, please see the svg (p. 297) terminal.
Animateset term domterm animate

The animate option resets the cursor position to the terminal top left at the start of every plot so thatsuccessive plots overwrite the same area on the screen. This may be desirable in order to create an in-place
animation.

Dumb
The dumb terminal driver plots into a text block using ascii characters. It has an optional size specification
and a trailing linefeed flag.
Syntax:set terminal dumb {size <xchars>,<ychars>} {[no]feed}{aspect <htic>{,<vtic>}}{[no]enhanced}{fillchar {solid|"<char>"}}{[no]attributes}{mono|ansi|ansi256|ansirgb}

where <xchars> and <ychars> set the size of the text block. The default is 79 by 24. The last newline isprinted only if feed is enabled.

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271

The aspect option can be used to control the aspect ratio of the plot by setting the length of the horizontal
and vertical tic marks. Only integer values are allowed. Default is 2,1 – corresponding to the aspect ratio ofcommon screen fonts.
The character "#" is used for area-fill. You can replace this with any character available in the terminal
font. fillchar solid is short for fillchar "\U+2588" (unicode FULL BLOCK).
The ansi, ansi256, and ansirgb options will include escape sequences in the output to handle colors. Notethat these might not be handled by your terminal. Default is mono. To obtain the best color match in ansi
mode, you should use set colorsequence classic. Depending on the mode, the dumb terminal will emit
the following sequences (without the additional whitespace):
ESC [ 0 m
reset attributes to defaults
foreground color:
ESC [ 1 m
set intense/bold
ESC [ 22 m
intense/bold off
ESC [ <fg> mwith color code 30 <= <fg> <= 37
ESC [ 39 m
reset to default
ESC [ 38; 5; <c> m with palette index 16 <= <c> <= 255
ESC [ 38; 2; <r>; <g>; <b> m with components 0 <= <r,g,b> <= 255
background color:
ESC [ <bg> mwith color code 40 <= <bg> <= 47
ESC [ 49 m
reset to default
ESC [ 48; 5; <c> m with palette index 16 <= <c> <= 231
ESC [ 48; 2; <r>; <g>; <b> m with components 0 <= <r,g,b> <= 255

See also e.g. the description at https://en.wikipedia.org/wiki/ANSI escape code#Colors
The attributes option enables bold and italic text on terminals or emulators that support the escapesequences
ESC [ 1 m / 22 m
ESC [ 3 m / 23 m

for bold on/off andfor italic on /off.

Example:set term dumb mono size 60,15 aspect 1
set tics nomirror scale 0.5
plot [-5:6.5] sin(x) with impulse ls -1
1 +-------------------------------------------------+
0.8 +|||++++||||++|
0.6 +|||||+++|||||||+ sin(x) +----+ |0.4 +||||||+++|||||||||+|
0.2 +|||||||+++|||||||||||++|
0 ++++++++++++++++++++++++++++++++++++++++++++++++++|-0.2 ++|||||||||||++|||||||||||+ |-0.4 ++|||||||||++|||||||||+ |-0.6 ++|||||||++|||||||+|-0.8 +++||||+++||||+|-1 +---+--------+--------+-------+--------+--------+-+
-4
-2
0
2
4
6

Dxf
Terminal driver dxf for export to AutoCad (Release 10.x). It has no options. The default size is 120x80
AutoCad units. dxf uses seven colors (white, red, yellow, green, cyan, blue and magenta) that can bechanged only by modifying the source file. If a black-and-white plotting device is used the colors are mapped
to differing line thicknesses. Note: someone please update this terminal to the 2012 DXF standard!

Emf
The emf terminal generates an Enhanced Metafile Format file. This file format is recognized by many
Windows applications.
Syntax:272

gnuplot 6.0
set terminal emf {color | monochrome}{enhanced {noproportional}}{rounded | butt}{linewidth <LW>} {dashlength <DL>}{size XX,YY} {background <rgb_color>}{font "<fontname>{,<fontsize>}"}{fontscale <scale>}

In monochrome mode successive line types cycle through dash patterns. linewidth <factor> multiplies
all line widths by this factor. dashlength <factor> is useful for thick lines. <fontname> is the name of afont; and <fontsize> is the size of the font in points.
The nominal size of the output image defaults to 1024x768 in arbitrary units. You may specify a different
nominal size using the size option.
Enhanced text mode tries to approximate proportional character spacing. If you are using a monospaced
font, or don’t like the approximation, you can turn off this correction using the noproportional option.
The default settings are color font "Arial,12" size 1024,768 Selecting default sets all options to theirdefault values.
Examples:set terminal emf 'Times Roman Italic, 12'

Epscairo
The epscairo terminal device generates encapsulated PostScript (*.eps) using the cairo and pango support
libraries. cairo version >= 1.6 is required.
Please read the help for the pdfcairo terminal.

Epslatex
The epslatex driver generates output for further processing by LaTeX.
Syntax:set terminal epslatex
set terminal epslatex{default}{standalone | input}{level1 | leveldefault | level3}{color | colour | monochrome}{background <rgbcolor> | nobackground}{dashlength | dl <DL>}{linewidth | lw <LW>} {pointscale | ps <PS>}{rounded | butt}{clip | noclip}{palfuncparam <samples>{,<maxdeviation>}}{size <XX>{unit},<YY>{unit}}{header <header> | noheader}{blacktext | colortext | colourtext}{{font} "fontname{,fontsize}" {<fontsize>}}{fontscale <scale>}

The epslatex terminal prints a plot as terminal postscript eps but transfers the texts to LaTeX insteadof including in the PostScript code. Thus, many options are the same as in the postscript terminal.
If you see the error message"Can't find PostScript prologue file ... "Please see and follow the instructions in postscript prologue (p. 292).
The option color enables color, while monochrome prefers black and white drawing elements. Further,monochrome uses gray palette but it does not change color of objects specified with an explicit colorspec.

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273

dashlength or dl scales the length of dashed-line segments by <DL>, which is a floating-point number
greater than zero. linewidth or lw scales all linewidths by <LW>.
By default the generated PostScript code uses language features that were introduced in PostScript Level 2,
notably filters and pattern-fill of irregular objects such as filledcurves. PostScript Level 2 features are conditionally protected so that PostScript Level 1 interpreters do not issue errors but, rather, display a message
or a PostScript Level 1 approximation. The level1 option substitutes PostScript Level 1 approximationsof these features and uses no PostScript Level 2 code. This may be required by some old printers and old
versions of Adobe Illustrator. The flag level1 can be toggled later by editing a single line in the PostScript
output file to force PostScript Level 1 interpretation. In the case of files containing level 2 code, the above
features will not appear or will be replaced by a note when this flag is set or when the interpreting program
does not indicate that it understands level 2 PostScript or higher. The flag level3 enables PNG encoding
for bitmapped images, which can reduce the output size considerably.
rounded sets line caps and line joins to be rounded; butt is the default, butt caps and mitered joins.
clip tells PostScript to clip all output to the bounding box; noclip is the default.
palfuncparam controls how set palette functions are encoded as gradients in the output. Analytic
color component functions (set via set palette functions) are encoded as linear interpolated gradientsin the postscript output: The color component functions are sampled at <samples> points and all points
are removed from this gradient which can be removed without changing the resulting colors by more than<maxdeviation>. For almost every useful palette you may safely leave the defaults of <samples>=2000 and<maxdeviation>=0.003 untouched.
The default size for postscript output is 10 inches x 7 inches. The default for eps output is 5 x 3.5 inches.
The size option changes this to whatever the user requests. By default the X and Y sizes are taken to be in
inches, but other units are possibly (currently only cm). The BoundingBox of the plot is correctly adjusted
to contain the resized image. Screen coordinates always run from 0.0 to 1.0 along the full length of the plotedges as specified by the size option.
blacktext forces all text to be written in black even in color mode;
The epslatex driver offers a special way of controlling text positioning: (a) If any text string begins with ’{’,
you also need to include a ’}’ at the end of the text, and the whole text will be centered both horizontallyand vertically by LaTeX. (b) If the text string begins with ’[’, you need to continue it with: a position
specification (up to two out of t,b,l,r,c), ’]{’, the text itself, and finally, ’}’. The text itself may be anything
LaTeX can typeset as an LR-box. \rule{}{}’s may help for best positioning. See also the documentation forthe pslatex (p. 293) terminal driver. To create multiline labels, use \shortstack, for example
set ylabel '[r]{\shortstack{first line \\ second line}}'

The back option of set label commands is handled slightly different than in other terminals. Labels using’back’ are printed behind all other elements of the plot while labels using ’front’ are printed above everythingelse.
The driver produces two different files, one for the eps part of the figure and one for the LaTeX part. The
name of the LaTeX file is taken from the set output command. The name of the eps file is derived byreplacing the file extension (normally .tex) with .eps instead. There is no LaTeX output if no output file isgiven! Remember to close the output file before next plot unless in multiplot mode.
In your LaTeX documents use ’\input{filename}’ to include the figure. The .eps file is included by thecommand \includegraphics{...}, so you must also include \usepackage{graphicx} in the LaTeX preamble.
If you want to use coloured text (option textcolour) you also have to include \usepackage{color} in the
LaTeX preamble.
Pdf files can be made from the eps file using ’epstopdf’. If the graphics package is properly configured, the
LaTeX files can also be processed by pdflatex without changes, using the pdf files instead of the eps files.
The behaviour concerning font selection depends on the header mode. In all cases, the given font size is used
for the calculation of proper spacing. When not using the standalone mode the actual LaTeX font and fontsize at the point of inclusion is taken, so use LaTeX commands for changing fonts. If you use e.g. 12pt as
font size for your LaTeX document, use ’"" 12’ as options. The font name is ignored. If using standalone274

gnuplot 6.0

the given font and font size are used, see below for a detailed description.
If text is printed coloured is controlled by the TeX booleans \ifGPcolor and \ifGPblacktext. Only if\ifGPcolor is true and \ifGPblacktext is false, text is printed coloured. You may either change them in
the generated TeX file or provide them globally in your TeX file, for example by using\newif\ifGPblacktext\GPblacktexttrue

in the preamble of your document. The local assignment is only done if no global value is given.
When using the epslatex terminal give the name of the TeX file in the set output command including thefile extension (normally ".tex"). The eps filename is generated by replacing the extension by ".eps".
If using the standalone mode a complete LaTeX header is added to the LaTeX file; and "-inc" is added
to the filename of the eps file. The standalone mode generates a TeX file that produces output with thecorrect size when using dvips, pdfTeX, or VTeX. The default, input, generates a file that has to be included
into a LaTeX document using the \input command.
If a font other than "" or "default" is given it is interpreted as LaTeX font name. It contains up to three parts,
separated by a comma: ’fontname,fontseries,fontshape’. If the default fontshape or fontseries are requested,
they can be omitted. Thus, the real syntax for the fontname is ’[fontname][,fontseries][,fontshape]’. The
naming convention for all parts is given by the LaTeX font scheme. The fontname is 3 to 4 characterslong and is built as follows: One character for the font vendor, two characters for the name of the font, andoptionally one additional character for special fonts, e.g., ’j’ for fonts with old-style numerals or ’x’ for expert
fonts. The names of many fonts is described in http://www.tug.org/fontname/fontname.pdf
For example, ’cmr’ stands for Computer Modern Roman, ’ptm’ for Times-Roman, and ’phv’ for Helvetica.
The font series denotes the thickness of the glyphs, in most cases ’m’ for normal ("medium") and ’bx’ or’b’ for bold fonts. The font shape is ’n’ for upright, ’it’ for italics, ’sl’ for slanted, or ’sc’ for small caps, ingeneral. Some fonts may provide different font series or shapes.
Examples:Use Times-Roman boldface (with the same shape as in the surrounding text):
set terminal epslatex 'ptm,bx'

Use Helvetica, boldface, italics:
set terminal epslatex 'phv,bx,it'

Continue to use the surrounding font in slanted shape:
set terminal epslatex ',,sl'Use small capitals:
set terminal epslatex ',,sc'

By this method, only text fonts are changed. If you also want to change the math fonts you have to use the"gnuplot.cfg" file or the header option, described below.
In standalone mode, the font size is taken from the given font size in the set terminal command. To beable to use a specified font size, a file "size<size>.clo" has to reside in the LaTeX search path. By default,
10pt, 11pt, and 12pt are supported. If the package "extsizes" is installed, 8pt, 9pt, 14pt, 17pt, and 20pt areadded.
The header option takes a string as argument. This string is written into the generated LaTeX file. If using
the standalone mode, it is written into the preamble, directly before the \begin{document} command. In
the input mode, it is placed directly after the \begingroup command to ensure that all settings are local tothe plot.
Examples:Use T1 fontencoding, change the text and math font to Times-Roman as well as the sans-serif font toHelvetica:
set terminal epslatex standalone header \"\\usepackage[T1]{fontenc}\n\\usepackage{mathptmx}\n\\usepackage{helvet}"gnuplot 6.0

275

Use a boldface font in the plot, not influencing the text outside the plot:
set terminal epslatex input header "\\bfseries"

If the file "gnuplot.cfg" is found by LaTeX it is input in the preamble the LaTeX document, when using
standalone mode. It can be used for further settings, e.g., changing the document font to Times-Roman,
Helvetica, and Courier, including math fonts (handled by "mathptmx.sty"):\usepackage{mathptmx}\usepackage[scaled=0.92]{helvet}\usepackage{courier}

The file "gnuplot.cfg" is loaded before the header information given by the header command. Thus, you
can use header to overwrite some of settings performed using "gnuplot.cfg"

Epson 180dpi
Note: only available if gnuplot is configured –with-bitmap-terminals. This driver supports a family of Epson
printers and derivatives.
epson 180dpi and epson 60dpi are drivers for Epson LQ-style 24-pin printers with resolutions of 180 and
60 dots per inch, respectively.
epson lx800 is a generic 9-pin driver appropriate for printers like the Epson LX-800, the Star NL-10 and
NX-1000, the PROPRINTER, and so forth.
nec cp6 is generic 24-pin driver that can be used for printers like the NEC CP6 and the Epson LQ-800.
The okidata driver supports the 9-pin OKIDATA 320/321 Standard printers.
The starc driver is for the Star Color Printer.
The tandy 60dpi driver is for the Tandy DMP-130 series of 9-pin, 60-dpi printers.
The dpu414 driver is for the Seiko DPU-414 thermal printer.
nec cp6 has the options:
Syntax:set terminal nec_cp6 {monochrome | colour | draft}which defaults to monochrome.
dpu414 has the options:
Syntax:set terminal dpu414 {small | medium | large} {normal | draft}which defaults to medium (=font size) and normal. Preferred combinations are medium normal and small
draft.

Fig
The fig terminal device generates output in the Fig graphics language for import into the xfig interactive
drawing tool. Notes:
The fig terminal was significantly revised in gnuplot version 5.3.
Currently only version 3.2 of the fig file format is supported.
Use of dash patterns may require Xfig 3.2.6 or newer.

Syntax:set terminal fig {monochrome | color}{small | big | size <xsize>{in|cm},<ysize>{in|cm}}{landscape | portrait}{pointsmax <max_points>}{font "<fontname>{,<fontsize>}"} {fontsize <size>}{textnormal | {textspecial texthidden textrigid}}{{linewidth|lw} <multiplier>}

276

gnuplot 6.0

The default settings are
set term fig color small landscape font "Times Roman,10" lw 1.0

size sets the size of the drawing area to <xsize>*<ysize> in units of inches (default) or centimeters. The
default is size 5in,3in. small is shorthand for size 5in,3in (3in,5in in portrait mode). big is shorthandfor size 8in,5in.
pointsmax sets the maximum number of vertices in a polyline; longer polylines will be broken into segments.
font sets the text font face to <fontname> and its size to <fontsize> points. Choice is limited to the 35
standard PostScript fonts. textnormal resets the text flags and selects postscript fonts, textspecial sets
the text flags for LaTeX specials, texthidden sets the hidden flag and textrigid the rigid flag.
linewidth is a multiplier for the linewidth property of all lines.
Additional point-plot symbols are also available in the fig driver. The symbols can be used through pointtype values % 100 above 50, with different fill intensities controlled by <pointtype> % 5 and outlines inblack (for <pointtype> % 10 < 5) or in the current color. Available symbols are
50 - 59:
60 - 69:
70 - 79:
80 - 89:
90 - 99:

circlessquares
diamonds
upwards triangles
downwards triangles

The size of these symbols scales with the font size.
RGB colors will be replaced with gray unless they have been defined in a linetype prior to plotting or matcha known named color or palette value. See colornames (p. 160). E.g.
set linetype 999 lc rgb '#aabbcc'
plot $data with fillecurve fillcolor rgb '#aabbcc'

Gif
Syntax:set terminal gif{{no}enhanced}{{no}transparent} {rounded|butt}{linewidth <lw>} {dashlength <dl>}{tiny | small | medium | large | giant}{font "<face> {,<pointsize>}"} {fontscale <scale>}{size <x>,<y>} {{no}crop}{background <rgb_color>}{animate {delay <d>} {loop <n>} {optimize}}

PNG, JPEG and GIF images are created using the external library libgd. GIF plots may be viewed interactively by piping the output to the ’display’ program from the ImageMagick package as follows:
set term gif
set output '| display gif:-'

You can view the output from successive plot commands interactively by typing <space> in the display
window. To save the current plot to a file, left click in the display window and choose save.
transparent instructs the driver to make the background color transparent. Default is notransparent.
The linewidth and dashlength options are scaling factors that affect all lines drawn, i.e. they are multipliedby values requested in various drawing commands.
butt instructs the driver to use a line drawing method that does not overshoot the desired end point of aline. This setting is only applicable for line widths greater than 1. This setting is most useful when drawing
horizontal or vertical lines.
The output plot size <x,y> is given in pixels — it defaults to 640x480. Please see additional information
under canvas (p. 32) and set size (p. 213). Blank space at the edges of the finished plot may be trimmed
using the crop option, resulting in a smaller final image size. Default is nocrop.

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277

Animateset term gif animate {delay <d>} {loop <n>} {{no}optimize}}

The gif terminal animate option creates a single gif file containing multiple frames. The delay between
display of successive frames may be specified in units of 1/100 second (default 5), but this value may or may
not be honored accurately by a program used to view the animation later. The number of animation loops
during playback can be specified, with the default of 0 meaning unlimited looping. Again this value may or
may not be honored by the program later used for viewing. An animation sequence is terminated by thenext set output or set term command.
Example showing continuous rotation:
set term gif animate loop 0
set output 'rotating_surface.gif'
do for [ang=1:359] {set view 60, ang
splot f(x,y) with pm3d}
unset output

Optimize
set term gif animate optimize

The optimize option [DEPRECATED] is passed to the gd library when the output file is opened. It has
two effects on the animation.
1) A single color map is used for the entire animation. This requires that all colors used in any frame of theanimation are already defined in the first frame.
2) If possible, only the portions of a frame that differ from the previous frame are stored in the animation
file. This space saving may not be possible if the animation uses transparency.
Both of these optimizations are intended to produce a smaller output file, but the decrease in size is probably
only significant for long animations. Caveat: The implementation of optimization in libgd is known to be
buggy. Therefore use of this option in gnuplot is not recommended.
Fonts
The details of font selection are complicated. For more information please see the separate section under
fonts gd (p. 54).
Examples:set terminal gif medium noenhanced size 640,480 background '#ffffff'

Use the medium size built-in non-scaleable, non-rotatable font. Enhanced text mode will not work with thisfont. Use white (24 bit RGB in hexadecimal) for the non-transparent background.
set terminal gif font arial 14

Searches for a font with face name ’arial’ and sets the font size to 14pt.

Gpic
Note: Legacy terminal (present only if gnuplot was configured –with-gpic). The gpic terminal driver generates GPIC graphs in the Free Software Foundations’s "groff" package. The default size is 5 x 3 inches. The
only option is the origin, which defaults to (0,0).
Syntax:set terminal gpic {<x> <y>}where x and y are in inches.
A simple graph can be formatted using

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gnuplot 6.0
groff -p -mpic -Tps file.pic > file.ps.

The output from pic can be pipe-lined into eqn, so it is possible to put complex functions in a graph withthe set label and set {x/y}label commands. For instance,
set ylab '@space 0 int from 0 to x alpha ( t ) roman d t@'

will label the y axis with a nice integral if formatted with the command:
gpic filename.pic | geqn -d@@ -Tps | groff -m[macro-package] -Tps
> filename.ps

Figures made this way can be scaled to fit into a document. The pic language is easy to understand, so thegraphs can be edited by hand if need be. All co-ordinates in the pic-file produced by gnuplot are given as
x+gnuplotx and y+gnuploty. By default x and y are given the value 0. If this line is removed with an editor
in a number of files, one can put several graphs in one figure like this (default size is 5.0x3.0 inches):.PS 8.0
x=0;y=3
copy "figa.pic"
x=5;y=3
copy "figb.pic"
x=0;y=0
copy "figc.pic"
x=5;y=0
copy "figd.pic".PE

This will produce an 8-inch-wide figure with four graphs in two rows on top of each other.
One can also achieve the same thing by specifying x and y in the command
set terminal gpic x y

GrassNote: legacy terminal. The grass terminal driver gives gnuplot capabilities to users of the GRASS geographic information system. Contact grassp-list@moon.cecer.army.mil for more information. Pages are
written to the current frame of the GRASS Graphics Window. There are no options.

HP terminals
Gnuplot provides two generic terminals for old Hewlett-Packard pen plotters and printers. The HPGL printercontrol language was introduced in 1974 and is recognized by many plotters and printers from that era. See
set term hpgl (p. 278). The PCL5 printer control language was introduced in 1990 and became standard
for many devices by HP and others. See set term pcl5 (p. 284). Both of these terminals are included ingnuplot by default.
There are also legacy terminals to support specific plotters (hp26 hp2648), inkjet printers (hp500c), andearly laserjet printers (hplj hpljii). These are not included unless you modify the source code file term.h.

Hpgl
Syntax:set terminal hpgl {<number_of_pens>} {eject} {fontscale <scale>}

The hpgl driver produces HPGL output for Hewlett Packard pen plotters like the HP7475A and many otherplotters dating back to the 1970s. Also, HPGL graphics can be imported by many software packages. The
HPGL command language was largely superseded in later printers by the PCL command language. See set
term pcl5 (p. 284).

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Terminal options control the number of pens used and whether or not the plotter ejects a page when done.
The default is to use 6 pens and not eject the page.
All text is drawn in a uniform size. The fontscale option applies a scale factor to make this size larger orsmaller. If gnuplot’s current encoding is set to either iso 8859 1 cp850, non-ascii characters are translated
for handling by some printer models that support the corresponding character set. If your printer model
does not support this, do not set these encodings.

ImagenThe imagen terminal driver supports Imagen laser printers. It is capable of placing multiple graphs on asingle page.
Syntax:set terminal imagen {<fontsize>} {portrait | landscape}{[<horiz>,<vert>]}where fontsize defaults to 12 points and the layout defaults to landscape. <horiz> and <vert> are thenumber of graphs in the horizontal and vertical directions; these default to unity.
Example:set terminal imagen portrait [2,3]puts six graphs on the page in three rows of two in portrait orientation.

Jpeg
Syntax:set terminal jpeg{{no}enhanced}{{no}interlace}{linewidth <lw>} {dashlength <dl>} {rounded|butt}{tiny | small | medium | large | giant}{font "<face> {,<pointsize>}"} {fontscale <scale>}{size <x>,<y>} {{no}crop}{background <rgb_color>}

PNG, JPEG and GIF images are created using the external library libgd. In most cases, PNG is to bepreferred for single plots, and GIF for animations. Both are loss-less image formats, and produce better
image quality than the lossy JPEG format. This is in particular noticeable for solid color lines against asolid background, i.e. exactly the sort of image typically created by gnuplot.
The interlace option creates a progressive JPEG image. Default is nointerlace.
The linewidth and dashlength options are scaling factors that affect all lines drawn, i.e. they are multipliedby values requested in various drawing commands.
butt instructs the driver to use a line drawing method that does not overshoot the desired end point of aline. This setting is only relevant for line widths greater than 1. The alternative is rounded.
The details of font selection are complicated. Two equivalent simple examples are given below:
set term jpeg font arial 11
set term jpeg font "arial,11"

For more information please see the separate section under fonts (p. 54).
The output plot size <x,y> is given in pixels — it defaults to 640x480. Please see additional information
under canvas (p. 32) and set size (p. 213). Blank space at the edges of the finished plot may be trimmed
using the crop option, resulting in a smaller final image size. Default is nocrop.

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Kittycairo
The kittycairo terminal generates in-window output on terminal emulators that support the kitty graphics
protocol. The actual drawing is done via cairo, a 2D graphics library, and pango, a library for text rendering.
The kitty protocol is an alternative to sixel graphics, with the advantage of support for 24-bit RGB colors
and slightly lower required bandwidth to transfer the image data between computer and terminal in a remotesession.
Syntax:set terminal kittycairo{{no}enhanced} {mono|color}{font <font>} {fontscale <scale>}{linewidth <lw>} {rounded|butt|square} {dashlength <dl>}{transparent | background <rgbcolor>}{size <XX>,<YY>} {anchor|scroll}This terminal processes labels and other text using enhanced formatting by default. See enhanced (p. 34).
The width of all lines in the plot can be modified by the factor <lw> specified in linewidth. The font size
can similarly be uniformly modified the scale factor provided by fontscale. For discussion of font and text
encoding options, see the pdfcairo (p. 285) terminal. The option rounded sets line caps and line joins to
be rounded; butt is the default, producing butt caps and mitered joins.
The size of the plot is given in screen pixels. By default (anchor) each plot is drawn at the top left of theterminal window. This is useful for animation or pseudo-mousing using the keyboard (see pseudo-mousing(p. 120)). scroll instead starts each plot at the current cursor position so that it scrolls with the terminal
text.

Kittygd
Syntax:set terminal kittygd{{no}enhanced} {{no}truecolor} {rounded|butt}{linewidth <lw>} {dashlength <dl>}{font "<face> {,<pointsize>}"} {fontscale <scale>}{size <x>,<y>} {anchor|scroll}{background <rgb_color>}

The kittygd terminal generates in-window output on terminal emulators that support the kitty graphics
protocol. The plot is composed using the gdlib library. By default the library creates a 24-bit RGB png
image that is mapped down onto 256 colors (truecolor) for output. notruecolor restricts the output tofewer colors but there is no obvious advantage to this. Transparent fill styles require the truecolor option.
See fillstyle (p. 217). If your copy of gnuplot was built with support for cairo graphics, the kittycairo
terminal may be preferable.
This terminal processes labels and other text using enhanced formatting by default. See enhanced (p. 34).
The width of al lines in the pot can be modified by the factor <lw> specified in linewidth. The font size
can similarly be uniformly modified by the scale factor provided in fontscale. For discussion of font andtext encoding options, see the png (p. 287) terminal.
butt instructs the driver to use a line drawing method that does not overshoot the desired end point of aline. This setting is only relevant for line widths greater than 1. The alternative is rounded, which produces
somewhat more uniform curved lines but can be much slower.
The size of the plot is given in screen pixels. By default (anchor) each new plot is drawn starting at the
top left of the window. This is useful for animation or pseudo-mousing using the keyboard (see pseudomousing (p. 120)). The scroll option instead plots at the current cursor position so that successive plots
scroll with the terminal text.

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Latex
Gnuplot provides a variety of terminals for use with TeX/LaTeX.
(1) TeX/LaTeX compatible terminals based on use of PostScript See epslatex (p. 272), pslatex (p. 293),
and pstricks (p. 294).
(2) TeX/LaTeX compatible terminals based on cairo graphics See cairolatex (p. 262).
(3) The tikz terminal uses an external lua script (see lua (p. 281)) to produce files for the PGF and TikZ
packages. Use the command set term tikz help to print terminal options.
(4) The pict2e terminal (added in version 5.4) replaces a set of legacy terminals latex, emtex, eepic, andtpic present in older versions of gnuplot. See pict2e (p. 286).
(5) Others, see context (p. 268) and legacy terminal texdraw (p. 298).
A summary of TeX-friendly terminals is available here: http://www.gnuplot.info/docs/latex demo.pdf

Linux console
Older gnuplot versions required special terminals linux or vgagl in order to display graphics on the linux
console, i.e. in the absence of X11 or other windowing environment. These terminals have been deprecated.
The recommended way to run gnuplot from the linux console is now to use a console terminal emulator suchas yaft (https://github.com/uobikiemukot/yaft) that supports sixel graphics. With yaft as your console
terminal you can run gnuplot and select a terminal with sixel output. See sixelgd (p. 296). As a fall-back
option you could use set term dumb, but sixel graphics are much nicer.

Lua
The lua generic terminal driver works in conjunction with an external Lua script to create a target-specificplot file. Currently the only supported target is TikZ -> pdflatex.
Information about Lua is available at http://www.lua.org .
Syntax:set terminal lua <target name> | "<file name>"{<script_args> ...}
{help}

A ’target name’ or ’file name’ (in quotes) for a script is mandatory. If a ’target name’ for the script isgiven, the terminal will look for "gnuplot-<target name>.lua" in the local directory and on failure in theenvironmental variable GNUPLOT LUA DIR.
All arguments will be provided to the selected script for further evaluation. E.g. ’set term lua tikz help’ willcause the script itself to print additional help on options and choices for the script.
Lua tikz
The TikZ driver is one output mode of the generic Lua terminal.
Syntax:set terminal lua tikz
{latex | tex | context}{color | monochrome}{nooriginreset | originreset}{nogparrows | gparrows}{nogppoints | gppoints}{picenvironment | nopicenvironment}

282

gnuplot 6.0{noclip | clip}{butt}{notightboundingbox | tightboundingbox}{background "<colorpec>"}{size <x>{unit},<y>{unit}}{scale <x>,<y>}{plotsize <x>{unit},<y>{unit}}{charsize <x>{unit},<y>{unit}}{font "<fontdesc>"}{{fontscale | textscale} <scale>}{dashlength | dl <DL>}{linewidth | lw <LW>}{nofulldoc | nostandalone | fulldoc | standalone}{{preamble | header} "<preamble_string>"}{tikzplot <ltn>,...}{notikzarrows | tikzarrows}{rgbimages | cmykimages}{noexternalimages|externalimages}{bitmap | nobitmap}{providevars <var name>,...}{createstyle}{help}For all options that expect lengths as their arguments they will default to ’cm’ if no unit is specified. For all
lengths the following units may be used: ’cm’, ’mm’, ’in’ or ’inch’, ’pt’, ’pc’, ’bp’, ’dd’, ’cc’. Blanks between
numbers and units are not allowed.
’monochrome’ disables line coloring and switches to grayscaled fills.
’originreset’ moves the origin of the TikZ picture to the lower left corner of the plot. It may be used to alignseveral plots within one tikzpicture environment. This is not tested with multiplots and pm3d plots!
’gparrows’ use gnuplot’s internal arrow drawing function instead of the ones provided by TikZ.
’gppoints’ use gnuplot’s internal plotmark drawing function instead of the ones provided by TikZ.
’nopicenvironment’ omits the declaration of the ’tikzpicture’ environment in order to set it manually. Thispermits putting some PGF/TikZ code directly before or after the plot.
’clip’ crops the plot at the defined canvas size. Default is ’noclip’ by which only a minimum bounding box ofthe canvas size is set. Neither a fixed bounding box nor a crop box is set if the ’plotsize’ or ’tightboundingbox’
option is used.
’butt’ changes the linecap property to "butt" and the linejoin property to "miter". The defaults are "round"and "round".
If ’tightboundingbox’ is set the ’clip’ option is ignored and the final bounding box is the natural boundingbox calculated by tikz.
’background’ sets the background color to the value specified in the <colorpec> argument. <colorspec>must be a valid color name or a 3 byte RGB code as a hexadecimal number with a preceding number sign(’#’). E.g. ’#ff0000’ specifies pure red. If omitted the background is transparent.
The ’size’ option expects two lengths <x> and <y> as the canvas size. The default size of the canvas is
12.5cm x 8.75cm.
The ’scale’ option works similar to the ’size’ option but expects scaling factors <x> and <y> instead oflengths.
The ’plotsize’ option permits setting the size of the plot area instead of the canvas size, which is the usual
gnuplot behaviour. Using this option may lead to slightly asymmetric tic lengths. Like ’originreset’ thisoption may not lead to convenient results if used with multiplots or pm3d plots. An alternative approach is
to set all margins to zero and to use the ’noclip’ option. The plot area has then the dimensions of the given
canvas sizes.
The ’charsize’ option expects the average horizontal and vertical size of the used font. Look at the generated
style file for an example of how to use it from within your TeX document.

gnuplot 6.0

283’fontscale’ or ’textscale’ expects a scaling factor as a parameter. All texts in the plot are scaled by this factorthen.
’dashlength’ or ’dl’ scales the length of dashed-line segments by <DL>, which is a floating-point number
greater than zero. ’linewidth’ or ’lw’ scales all linewidths by <LW>.
The options ’tex’, ’latex’ and ’context’ choose the TeX output format. LaTeX is the default. To load thestyle file put the according line at the beginning of your document:\input gnuplot-lua-tikz.tex\usepackage{gnuplot-lua-tikz}\usemodule[gnuplot-lua-tikz]% (for plain TeX)
% (for LaTeX)% (for ConTeXt)’createstyle’ derives the TeX/LaTeX/ConTeXt styles from the script and writes them to the appropriate
files.
’fulldoc’ or ’standalone’ produces a full LaTeX document for direct compilation.
’preamble’ or ’header’ may be used to put any additional LaTeX code into the document preamble instandalone mode.
With the ’tikzplot’ option the ’\path plot’ command will be used instead of only ’\path’. The following listof numbers of linetypes (<ltn>,...) defines the affected plotlines. There exists a plotstyle for every linetype.
The default plotstyle is ’smooth’ for every linetype >= 1.
By default the tikz terminal produces simple LaTeX arrows. To produce arrows in accord with gnuplot’s’arrowstyle’ settings, use the ’gparrows’ option. The ’tikzarrows’ option is a third alternative that bypasses
both of these. Instead the arrowstyle ’angle’ parameter is used to index a set of 12 pre-defined TikZ arrowstyles. E.g. an arrow style with the angle ’7’ will be mapped to the TikZ style ’gp arrow 7’ ignoring all otherarrowstyle settings.
With ’cmykimages’ the CMYK color model will be used for inline image data instead of the RGB model.
All other colors (like line colors etc.) are not affected by this option, since they are handled e.g. by LaTeX’s
xcolor package. This option is ignored if images are externalized.
By using the ’externalimages’ option all bitmap images will be written as external PNG images and included
at compile time of the document. Generating DVI and later postscript files requires to convert the PNGs
into EPS files in a separate step e.g. by using ImageMagick’s convert. Transparent bitmap images arealways generated as an external PNGs.
The ’nobitmap’ option let images be rendered as filled rectangles instead of the nativ PS or PDF inline image
format. This option is ignored if images are externalized.
The ’providevars’ options makes gnuplot’s internal and user variables available by using the ’\gpgetvar{<varname>}’ command within the TeX script. Use gnuplot’s ’show variables all’ command to see the list of valid
variables.
The <fontdesc> string may contain any valid TeX/LaTeX/ConTeXt font commands like e.g. ’\small’. It
is passed directly as a node parameter in form of "font={<fontdesc>}". This can be ’misused’ to add
further code to a node, e.g. ’\small,yshift=1ex’ or ’,yshift=1ex’ are also valid while the latter does notchange the current font settings. One exception is the second argument of the list. If it is a number ofthe form <number>{unit} it will be interpreted as a fontsize like in other terminals and will be appended
to the first argument. If the unit is omitted the value is interpreted as ’pt’. As an example the string’\sffamily,12,fill=red’ sets the font to LaTeX’s sans serif font at a size of 12pt and red background color. The
same applies to ConTeXt, e.g. ’\switchtobodyfont[iwona],10’ changes the font to Iwona at a size of 10pt.
Plain TeX users have to change the font size explicitly within the first argument. The second should be set
to the same value to get proper scaling of text boxes.
Strings have to be put in single or double quotes. Double quoted strings may contain special characters likenewlines ’\n’ etc.

284gnuplot 6.0

Pbm
Note: only available if gnuplot is configured –with-bitmap-terminals. Syntax:
set terminal pbm {<fontsize>} {<mode>} {size <x>,<y>}where <fontsize> is small, medium, or large and <mode> is monochrome, gray or color. The default
plot size is 640 pixels wide and 480 pixels high. The output size is white-space padded to the nearest multipleof 8 pixels on both x and y. This empty space may be cropped later if needed.
The output of the pbm driver depends upon <mode>: monochrome produces a portable bitmap (one bit
per pixel), gray a portable graymap (three bits per pixel) and color a portable pixmap (color, four bits per
pixel).
The output of this driver can be used with various image conversion and manipulation utilities provided by
NETPBM. Based on Jef Poskanzer’s PBMPLUS package, NETPBM provides programs to convert the above
PBM formats to GIF, TIFF, MacPaint, Macintosh PICT, PCX, X11 bitmap and many others. Complete
information is available at http://netpbm.sourceforge.net/.
Examples:set terminal pbm small monochrome# defaults
set terminal pbm color medium size 800,600
set output '| pnmrotate 45 | pnmtopng > tilted.png' # uses NETPBM

Pcl5
The pcl5 driver supports Hewlett Packard and other printers from the 1990s and later.
Syntax:set terminal pcl5 {<mode>} {{no}enhanced}{size <plotsize> | size <width>{unit},<height>{unit}}{font "<fontname>,<size>"} {pspoints | nopspoints}{fontscale <scale>} {pointsize <scale>} {linewidth <scale}{rounded|butt} {color <number_of_pens>}<mode> is landscape or portrait. <plotsize> is the physical plotting size of the plot, which can be oneof the following formats: letter for standard (8 1/2" X 11") displays, legal for (8 1/2" X 14") displays,
noextended for (36" X 48") displays (a letter size ratio), extended for (36" X 55") displays (almost alegal size ratio), or a4 for (296mm X 210mm) displays. You can also explicitly specify the canvas size using
the width and height options. Default unit is in. Default size is letter.
<fontname> can be one of stick, univers (default), albertus, antique olive, arial, avant garde gothic,
bookman, zapf chancery, clarendon, coronet, courier courier ps, cg times, garamond antigua, helvetica,
helvetica narrow, letter gothic, marigold, new century schlbk, cg omega, palatino, times new roman,times roman, zapf dingbats, truetype symbols, or wingdings. Font names are case-insensitive and underscores may be replaced by spaces or dashes or may be left out. <fontsize> is the font size in points.
The point type selection can be the a limited default set by specifying nopspoints, or the same set of pointtypes as provided by the postscript terminal by specifying pspoints (default).
The butt option selects lines with butt ends and mitered joins (default), whereas rounded selects roundedline ends and joins.
Line widths, and point and font sizes can be scaled using the linewidth, pointscale, or fontscale options,
respectively.
color selects the number of pens <number of pens> used in plots. Default is 8, minimum 2.
Note that built-in support of some of these options is printer device dependent. For instance, all the fonts
are supposedly supported by the HP Laserjet IV, but only a few (e.g. univers, stick) may be supported by
the HP Laserjet III and the Designjet 750C. Also, color obviously won’t work on monochrome devices, but
newer ones will do grey-scale.

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Defaults: landscape, a4, 8 pens, univers, 12 point, pspoints, butt, no scaling
The pcl5 terminal will try to request fonts which match your encoding. Note that this has highest priority,
so you might end up with a different font face. The terminal’s default encoding is HP Roman-8.
Limitations:This terminal does not support alpha transparency. Transparent filling is emulated using shading patterns.
Boxed text is not implemented.
The support for UTF-8 is limited. Lacking the label mode for UTF-8 output in HP-GL/2, the driver reverts
to PCL for strings containing 8bit characters. UTF-8 text is limited to angles of 0, 90, 180, and 270 degrees.
Also vertical alignment might be off depending on the font.
Some enhanced text features (phantom box, overprinting) require using PCL features in addition to HPGL/2. This conforms to the specs but may not work with your printer or software.

Pdfcairo
The pdfcairo terminal device generates output in pdf. The actual drawing is done via cairo, a 2D graphics
library, and pango, a library for laying out and rendering text.
Syntax:set term pdfcairo{{no}enhanced} {mono|color}{font <font>} {fontscale <scale>}{linewidth <lw>} {rounded|butt|square} {dashlength <dl>}{background <rgbcolor>}{size <XX>{unit},<YY>{unit}}

This terminal processes labels and other text using enhanced formatting by default. See enhanced (p. 34).
The width of all lines in the plot can be modified by the factor <lw> specified in linewidth. The default
linewidth is 0.5 points. (1 "PostScript" point = 1/72 inch = 0.353 mm)
rounded sets line caps and line joins to be rounded; butt is the default, butt caps and mitered joins.
The default size for output is 5 inches x 3 inches. The size option changes this to whatever the user requests.
By default the X and Y sizes are taken to be in inches, but other units are possible (currently only cm).
font is in the format "FontFace,FontSize", i.e. the face and the size comma-separated in a single string.
FontFace is a usual font face name, such as ’Arial’. If you do not provide FontFace, the pdfcairo terminal
will use ’Sans’. FontSize is the font size, in points. If you do not provide it, the pdfcairo terminal will use
a nominal font size of 12 points. However, the default fontscale parameter for this terminal is 0.5, so theapparent font size is smaller than the nominal point size if the pdf output is viewed at full size.
Examples :set term pdfcairo font "Arial,12"
set term pdfcairo font "Serif" # to change the font face only
set term pdfcairo font ",14" # to change the font size only
set term pdfcairo font "" # to reset the font name and size

The fonts are retrieved from the usual fonts subsystems. Under Windows, those fonts are to be found andconfigured in the entry "Fonts" of the control panel. Under UNIX, they are handled by "fontconfig".
Pango, the library used to process the text, is based on utf-8. The pdfcairo terminal will convert from yourencoding to utf-8 if needed. The assumed input encoding is taken from your ’locale’. If your text actuallyuses a different encoding, make sure gnuplot knows which one you are using. See encoding (p. 166) for
more details.
Pango may give unexpected results with fonts that do not respect the unicode mapping. With the Symbol
font, for example, the pdfcairo terminal will use the map provided by http://www.unicode.org/ to translate character codes to unicode. Note that "the Symbol font" is to be understood as the Adobe Symbol.PFB". Alternatively, the OpenSymbol font, distributed
font, distributed with Acrobat Reader as "SY
with OpenOffice.org as "opens .ttf", offers the same characters. Microsoft has distributed a Symbol font286

gnuplot 6.0("symbol.ttf"), but it has a different character set with several missing or moved mathematic characters. If
you experience problems with your default setup (if the demo enhancedtext.dem is not displayed properly
for example), you probably have to install one of the Adobe or OpenOffice Symbol fonts, and remove theMicrosoft one. Other non-conform fonts, such as "wingdings" have been observed working.
The rendering of the plot involves two mechanisms : antialiasing and oversampling. Antialiasing producessmoother non-horizontal and non-vertical lines. Oversampling combined with antialiasing provides subpixel
accuracy, so that gnuplot can draw a line from non-integer coordinates. This avoids wobbling effects on
diagonal lines (’plot x’ for example).

Pict2eThe pict2e terminal uses the LaTeX2e variant of the picture environment. It replaces terminals which werebased on the original LaTeX picture environment: latex, emtex, tpic, and eepic.
Alternatives to this terminal with a more complete support of gnuplot’s features are tikz, pstricks, cairolatex, pslatex, epslatex and mp.
Syntax:set terminal pict2e{font "{<fontname>}{,<fontsize>}"}{size <XX>{unit}, <YY>{unit}}{color | monochrome}{linewidth <lw>} {rounded | butt}{texarrows | gparrows} {texpoints | gppoints}{smallpoints | tinypoints | normalpoints}

This terminal requires the following standard LaTeX packages: pict2e, xcolor, graphics/graphicx andamssymb. For pdflatex, the transparent package is used to support transparency.
By default the plot will inherit font settings from the embedding document. You have the option to force
a font with the font option, like cmtt (Courier) or cmr (Roman), instead. In this case you may also force
a specific fontsize. Otherwise the fontsize argument is used to estimate the required space for text. Unless
your driver is capable of building fonts at any size (e.g. dvips), stick to the standard 10, 11 and 12 point
sizes.
The default size for the plot is 5 inches by 3 inches. The size option changes this to whatever the user
requests. By default the X and Y sizes are taken to be in inches, but other units are possible (currently onlycm).
With texpoints, points are drawn using LaTeX commands like "\Diamond" and "\Box". These are provided by the the latexsym package, which is part of the base distribution and thus part of any LaTeX
implementation. Other point types use symbols from the amssymb package. With gppoints, the terminal
will use gnuplot’s internal routines for drawing point symbols instead.
With the texpoints option, you can select three different point sizes: normalpoints, smallpoints, andtinypoints.
color causes gnuplot to produce \color{...} commands so that the graphs are colored. Using this option,
you must include \usepackage{xcolor} in the preamble of your LaTeX document. monochrome will avoid
the use of any color commands in the output. Transparent color fill is available if pdflatex is used.
linewidth sets the scale factor for the width of lines. rounded sets line caps and line joins to be rounded.
butt sets butt caps and mitered joins and is the default.
pict2e only supports dotted lines, but not dashed lines. All default line types are solid. Use set linetypewith the dashtype property to change.
texarrows draws arrows using LaTeX commands which are shorter but do not offer all options. gparrows
selects drawing arrows using gnuplot’s own routine for full functionality instead.

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Pm
The pm terminal driver provides an OS/2 Presentation Manager window in which the graph is plotted. The
window is opened when the first graph is plotted. This window has its own online help as well as facilities
for printing and copying to the clipboard.
Syntax:set terminal pm{{server} {n} | noserver}{nopersist | persist}{enhanced | noenhanced}{font <fontspec>}{nowidelines | widelines}{fontscale <scale>}{linewidth <scale>}{pointscale <scale>}{{title} "title"}

If persist is specified, each graph appears in its own window and all windows remain open after gnuplot
exits. If server is specified, all graphs appear in the same window, which remains open when gnuplot exits.
This option takes an optional numerical argument which specifies an instance of the server process. Thus
multiple server windows can be in use at the same time.
If widelines is specified, all plots will be drawn with wide lines. If enhanced is specified, sub- andsuperscripts and multiple fonts are enabled (see enhanced text (p. 34) for details). Font names for thecore PostScript fonts may be abbreviated to a single letter (T/H/C/S for Times/Helvetica/Courier/Symbol).
linewidth, fontscale, pointscale can be used to scale the width of lines, the size of text, or the size of thepoint symbols.
If title is specified, it will be used as the title of the plot window. It will also be used as the name of theserver instance, and will override the optional numerical argument.
The gnuplot outboard driver, gnupmdrv.exe, is searched in the same directory as gnuplot itself. You canoverride that by defining one of the environment variables GNUPLOT DRIVER DIR or GNUPLOT. As alast resort the current directory and the PATH are tried to locate gnupmdrv.exe.

Png
Syntax:set terminal png{{no}enhanced}{{no}transparent} {{no}interlace}{{no}truecolor} {rounded|butt}{linewidth <lw>} {dashlength <dl>}{tiny | small | medium | large | giant}{font "<face> {,<pointsize>}"} {fontscale <scale>}{size <x>,<y>} {{no}crop}{background <rgb_color>}

PNG, JPEG and GIF images are created using the external library libgd. PNG plots may be viewed
interactively by piping the output to the ’display’ program from the ImageMagick package as follows:
set term png
set output '| display png:-'

You can view the output from successive plot commands interactively by typing <space> in the display
window. To save the current plot to a file, left click in the display window and choose save.
transparent instructs the driver to make the background color transparent. Default is notransparent.
interlace instructs the driver to generate interlaced PNGs. Default is nointerlace.
The linewidth and dashlength options are scaling factors that affect all lines drawn, i.e. they are multipliedby values requested in various drawing commands.

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By default the png terminal creates TrueColor images with 24 bits of color information per pixel. The
notruecolor option instead uses only 8 bits, (256 indexed colors). Transparent fill styles require the truecolor option. See fillstyle (p. 217). A transparent background is possible in either indexed or TrueColor
images. Antialiasing also requires TrueColor.
butt instructs the driver to use a line drawing method that does not overshoot the desired end point of aline. This setting is only relevant for line widths greater than 1. The alternative is rounded, which produces
somewhat more uniform curved lines if antialiasing is not available (notruecolor) but can be much slower.
The details of font selection are complicated. Two equivalent simple examples are given below:
set term png font arial 11
set term png font "arial,11"

For more information please see the separate section under fonts (p. 54).
The output plot size <x,y> is given in pixels — it defaults to 640x480. Please see additional information
under canvas (p. 32) and set size (p. 213). Blank space at the edges of the finished plot may be trimmed
using the crop option, resulting in a smaller final image size. Default is nocrop.
Examplesset terminal png font "arial,14" size 800,600 background "white"

Searches for a scalable font with face name ’arial’ and sets the font size to 14pt. Please see fonts (p. 54)
for details of how the font search is done.
set terminal png transparent enhanced

Use 24 bits of color information per pixel, with a transparent background. Use the enhanced text mode
to control the layout of strings to be printed.

Pngcairo
The pngcairo terminal device generates output in png. The actual drawing is done via cairo, a 2D graphics
library, and pango, a library for laying out and rendering text.
Syntax:set term pngcairo{{no}enhanced} {mono|color}{{no}transparent} {{no}crop} {background <rgbcolor>{font <font>} {fontscale <scale>}{linewidth <lw>} {rounded|butt|square} {dashlength <dl>}{pointscale <ps>}{size <XX>{unit},<YY>{unit}}

This terminal supports an enhanced text mode, which allows font and other formatting commands (subscripts, superscripts, etc.) to be embedded in labels and other text strings. The enhanced text mode syntax
is shared with other gnuplot terminal types. See enhanced (p. 34) for more details.
The width of all lines in the plot can be modified by the factor <lw>.
rounded sets line caps and line joins to be rounded; butt is the default, butt caps and mitered joins.
The default size for the output is 640 x 480 pixels. The size option changes this to whatever the user
requests. By default the X and Y sizes are taken to be in pixels, but other units are possible (currently cm
and inch). A size given in centimeters or inches will be converted into pixels assuming a resolution of 72 dpi.
Screen coordinates always run from 0.0 to 1.0 along the full length of the plot edges as specified by the size
option.
<font> is in the format "FontFace,FontSize", i.e. the face and the size comma-separated in a single string.
FontFace is a usual font face name, such as ’Arial’. If you do not provide FontFace, the pngcairo terminal
will use ’Sans’. FontSize is the font size, in points. If you do not provide it, the pngcairo terminal will use asize of 12 points.

gnuplot 6.0289

For example :set term pngcairo font "Arial,12"
set term pngcairo font "Arial" # to change the font face only
set term pngcairo font ",12" # to change the font size only
set term pngcairo font "" # to reset the font name and size

The fonts are retrieved from the usual fonts subsystems. Under Windows, those fonts are to be found andconfigured in the entry "Fonts" of the control panel. Under UNIX, they are handled by "fontconfig".
Pango, the library used to layout the text, is based on utf-8. Thus, the pngcairo terminal has to convert
from your encoding to utf-8. The default input encoding is based on your ’locale’. If you want to use anotherencoding, make sure gnuplot knows which one you are using. See encoding (p. 166) for more detail.
Pango may give unexpected results with fonts that do not respect the unicode mapping. With the Symbol
font, for example, the pngcairo terminal will use the map provided by http://www.unicode.org/ to translate character codes to unicode. Note that "the Symbol font" is to be understood as the Adobe Symbol.PFB". Alternatively, the OpenSymbol font, distributed
font, distributed with Acrobat Reader as "SY
with OpenOffice.org as "opens .ttf", offers the same characters. Microsoft has distributed a Symbol font("symbol.ttf"), but it has a different character set with several missing or moved mathematic characters. If
you experience problems with your default setup (if the demo enhancedtext.dem is not displayed properly
for example), you probably have to install one of the Adobe or OpenOffice Symbol fonts, and remove theMicrosoft one.
Rendering uses oversampling, antialiasing, and font hinting to the extent supported by the cairo and pango
libraries.

Postscript
Several options may be set in the postscript driver.
Syntax:set terminal postscript {default}
set terminal postscript {landscape | portrait | eps}{enhanced | noenhanced}{defaultplex | simplex | duplex}{fontfile {add | delete} "<filename>"| nofontfiles} {{no}adobeglyphnames}{level1 | leveldefault | level3}{color | colour | monochrome}{background <rgbcolor> | nobackground}{dashlength | dl <DL>}{linewidth | lw <LW>} {pointscale | ps <PS>}{rounded | butt}{clip | noclip}{palfuncparam <samples>{,<maxdeviation>}}{size <XX>{unit},<YY>{unit}}{blacktext | colortext | colourtext}{{font} "fontname{,fontsize}" {<fontsize>}}{fontscale <scale>}If you see the error message"Can't find PostScript prologue file ... "Please see and follow the instructions in postscript prologue (p. 292).
landscape and portrait choose the plot orientation. eps mode generates EPS (Encapsulated PostScript)
output, which is just regular PostScript with some additional lines that allow the file to be imported into avariety of other applications. (The added lines are PostScript comment lines, so the file may still be printed
by itself.) To get EPS output, use the eps mode and make only one plot per file. In eps mode the wholeplot, including the fonts, is reduced to half of the default size.
enhanced enables enhanced text mode features (subscripts, superscripts and mixed fonts). See enhanced(p. 34) for more information. blacktext forces all text to be written in black even in color mode;

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Duplexing in PostScript is the ability of the printer to print on both sides of the same sheet of paper. With
defaultplex, the default setting of the printer is used; with simplex only one side is printed; duplex prints
on both sides (ignored if your printer can’t do it).
"<fontname>" is the name of a valid PostScript font; and <fontsize> is the size of the font in PostScript
points. In addition to the standard postscript fonts, an oblique version of the Symbol font, useful formathematics, is defined. It is called "Symbol-Oblique".
default sets all options to their defaults: landscape, monochrome, dl 1.0, lw 1.0, defaultplex, enhanced, "Helvetica" and 14pt. Default size of a PostScript plot is 10 inches wide and 7 inches high.
The option color enables color, while monochrome prefers black and white drawing elements. Further,monochrome uses gray palette but it does not change color of objects specified with an explicit colorspec. dashlength or dl scales the length of dashed-line segments by <DL>, which is a floating-point
number greater than zero. linewidth or lw scales all linewidths by <LW>.
By default the generated PostScript code uses language features that were introduced in PostScript Level 2,
notably filters and pattern-fill of irregular objects such as filledcurves. PostScript Level 2 features are conditionally protected so that PostScript Level 1 interpreters do not issue errors but, rather, display a message
or a PostScript Level 1 approximation. The level1 option substitutes PostScript Level 1 approximationsof these features and uses no PostScript Level 2 code. This may be required by some old printers and old
versions of Adobe Illustrator. The flag level1 can be toggled later by editing a single line in the PostScript
output file to force PostScript Level 1 interpretation. In the case of files containing level 2 code, the above
features will not appear or will be replaced by a note when this flag is set or when the interpreting program
does not indicate that it understands level 2 PostScript or higher. The flag level3 enables PNG encoding
for bitmapped images, which can reduce the output size considerably.
rounded sets line caps and line joins to be rounded; butt is the default, butt caps and mitered joins.
clip tells PostScript to clip all output to the bounding box; noclip is the default.
palfuncparam controls how set palette functions are encoded as gradients in the output. Analytic
color component functions (set via set palette functions) are encoded as linear interpolated gradientsin the postscript output: The color component functions are sampled at <samples> points and all points
are removed from this gradient which can be removed without changing the resulting colors by more than<maxdeviation>. For almost every useful palette you may safely leave the defaults of <samples>=2000 and<maxdeviation>=0.003 untouched.
The default size for postscript output is 10 inches x 7 inches. The default for eps output is 5 x 3.5 inches.
The size option changes this to whatever the user requests. By default the X and Y sizes are taken to be in
inches, but other units are possibly (currently only cm). The BoundingBox of the plot is correctly adjusted
to contain the resized image. Screen coordinates always run from 0.0 to 1.0 along the full length of the plotedges as specified by the size option.
Fonts listed by fontfile or fontfile add encapsulate the font definitions of the listed font from a postscript
Type 1 or TrueType font file directly into the gnuplot output postscript file. Thus, the enclosed font canbe used in labels, titles, etc. See the section postscript fontfile (p. 291) for more details. With fontfile
delete, a fontfile is deleted from the list of embedded files. nofontfiles cleans the list of embedded fonts.
The postscript driver supports about 70 distinct pointtypes, selectable through the pointtype option onplot and set linetype.
Several possibly useful files about gnuplot’s PostScript are included in the /docs/psdoc subdirectory of thegnuplot distribution and at the distribution sites. These are "ps symbols.gpi" (a gnuplot command filethat, when executed, creates the file "ps symbols.ps" which shows all the symbols available through thepostscript terminal), "ps guide.ps" (a PostScript file that contains a summary of the enhanced syntax anda page showing what the octal codes produce with text and symbol fonts), "ps file.doc" (a text file that
contains a discussion of the organization of a PostScript file written by gnuplot), and "ps fontfile doc.tex"(a LaTeX file which contains a short documentation concerning the encapsulation of LaTeX fonts with aglyph table of the math fonts).
A PostScript file is editable, so once gnuplot has created one, you are free to modify it to your heart’sgnuplot 6.0

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desire. See the editing postscript (p. 291) section for some hints.
Editing postscript
The PostScript language is a very complex language — far too complex to describe in any detail in thisdocument. Nevertheless there are some things in a PostScript file written by gnuplot that can be changed
without risk of introducing fatal errors into the file.
For example, the PostScript statement "/Color true def" (written into the file in response to the command
set terminal postscript color), may be altered in an obvious way to generate a black-and-white version of
a plot. Similarly line colors, text colors, line weights and symbol sizes can also be altered in straight-forward
ways. Text (titles and labels) can be edited to correct misspellings or to change fonts. Anything can berepositioned, and of course anything can be added or deleted, but modifications such as these may require
deeper knowledge of the PostScript language.
The organization of a PostScript file written by gnuplot is discussed in the text file "ps file.doc" in thedocs/ps subdirectory of the gnuplot source distribution.
Postscript fontfile
set term postscript ... fontfile {add|delete} <filename>

The fontfile or fontfile add option takes one file name as argument and encapsulates this file into thepostscript output in order to make this font available for text elements (labels, tic marks, titles, etc.). The
fontfile delete option also takes one file name as argument. It deletes this file name from the list of
encapsulated files.
The postscript terminal understands some font file formats: Type 1 fonts in ASCII file format (extension".pfa"), Type 1 fonts in binary file format (extension ".pfb"), and TrueType fonts (extension ".ttf"). pfa
files are understood directly, pfb and ttf files are converted on the fly if appropriate conversion tools are
installed (see below). You have to specify the full filename including the extension. Each fontfile option
takes exact one font file name. This option can be used multiple times in order to include more than one
font file.
The search order for find font files is (1) absolute pathname or current working directory (2) any of thedirectories specified by set loadpath (3) the directory specified by set fontpath (4) the directory given in
environmental variable GNUPLOT FONTPATH.
To use the encapsulated font file you have to specify the font name, which normally is not the same as thefile name. When embedding a font file by using the fontfile option in interactive mode, the font name isprinted on the screen.
Example:set term post "VAGRoundedBT_Regular" 14 fontfile "bvrr8a.pfa"
Font file 'bvrr8a.pfa' contains the font 'VAGRoundedBT_Regular'.
Location: /usr/share/fonts/Type1/bvrr8a.pfa

When using pfa or pfb fonts, you can also find it out by looking into the font file. There is a line similar
to "/FontName /URWPalladioL-Bold def". The middle string without the slash is the fontname, here
"URWPalladioL-Bold". For TrueType fonts, this is not so easy since the font name is stored in a binary
format. In addition, they often have spaces in the font names which is not supported by Type 1 fonts (inwhich a TrueType is converted on the fly). The font names are changed in order to eliminate the spaces in
the fontnames. The easiest way to find out which font name is generated for use with gnuplot, start gnuplot
in interactive mode and type in "set terminal postscript fontfile ’<filename.ttf>’".
For converting font files (either ttf or pfb) to pfa format, the conversion tool has to read the font from a fileand write it to standard output. If the output cannot be written to standard output, on-the-fly conversion
is not possible.
For pfb files "pfbtops" is a tool which can do this. If this program is installed on your system the on
the fly conversion should work. Just try to encapsulate a pfb file. If the compiled in program call292

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does not work correctly you can specify how this program is called by defining the environment variable
GNUPLOT PFBTOPFA e.g. to "pfbtops %s". The %s will be replaced by the font file name and thus has
to exist in the string.
If you don’t want to do the conversion on the fly but get a pfa file of the font you can use the tool "pfb2pfa"
which is written in simple c and should compile with any c compiler. It is available from many ftp servers,
e.g. ftp://ftp.dante.de/tex-archive/fonts/utilities/ps2mf/
In fact, "pfbtopfa" and "pfb2ps" do the same job. "pfbtopfa" puts the resulting pfa code into a file, whereas"pfbtops" writes it to standard output.
TrueType fonts are converted into Type 1 pfa format, e.g. by using the tool "ttf2pt1" which is available
from http://ttf2pt1.sourceforge.net/
If the builtin conversion does not work, the conversion command can be changed by the environment variable
GNUPLOT TTFTOPFA. For usage with ttf2pt1 it may be set to "ttf2pt1 -a -e -W 0 %s - ". Here again,%s stands for the file name.
For special purposes you also can use a pipe (if available for your operating system). Therefore you start
the file name definition with the character "<" and append a program call. This program has to write pfa
data to standard output. Thus, a pfa file may be accessed by set fontfile "< cat garamond.pfa".
For example, including Type 1 font files can be used for including the postscript output in LaTeX documents.
The "european computer modern" font (which is a variant of the "computer modern" font) is available inpfb format from any CTAN server, e.g. ftp://ftp.dante.de/tex-archive/fonts/ps-type1/cm-super/For example, the file "sfrm1000.pfb" contains the normal upright fonts with serifs in the design size 10pt (fontname "SFRM1000"). The computer modern fonts, which are still necessary for mathematics, are available
from ftp://ftp.dante.de/tex-archive/fonts/cm/ps-type1/bluesky
With these you can use any character available in TeX. However, the computer modern fonts have a strange
encoding. (This is why you should not use cmr10.pfb for text, but sfrm1000.pfb instead.) The usage of TeX
fonts is shown in one of the demos. The file "ps fontfile doc.tex" in the /docs/psdoc subdirectory of thegnuplot source distribution contains a table with glyphs of the TeX mathfonts.
If the font "CMEX10" is embedded (file "cmex10.pfb") gnuplot defines the additional font "CMEX10Baseline". It is shifted vertically in order to fit better to the other glyphs (CMEX10 has its baseline at the
top of the symbols).
Postscript prologue
Each PostScript output file includes a %%Prolog section and possibly some additional user-defined sections
containing, for example, character encodings. These sections are copied from a set of PostScript prologue
files that are either compiled into the gnuplot executable or stored elsewhere on your computer. A default
directory where these files live is set at the time gnuplot is built. However, you can override this default
either by using the gnuplot command set psdir or by defining an environment variable GNUPLOT PS DIR.
See set psdir (p. 212).
Postscript adobeglyphnames
This setting is only relevant to PostScript output with UTF-8 encoding. It controls the names used todescribe characters with Unicode entry points higher than 0x00FF. That is, all characters outside of theLatin1 set. In general unicode characters do not have a unique name; they have only a unicode identification
code. However, Adobe have a recommended scheme for assigning names to certain ranges of characters(extended Latin, Greek, etc). Some fonts use this scheme, others do not. By default, gnuplot will use
the Adobe glyph names. E.g. the lower case Greek letter alpha will be called /alpha. If you specificnoadobeglyphnames then instead gnuplot will use /uni03B1 to describe this character. If you get thissetting wrong, the character may not be found even if it is present in the font. It is probably always correct
to use the default for Adobe fonts, but for other fonts you may have to try both settings. See also fontfilegnuplot 6.0

293(p. 291).

Pslatex and pstex
The pslatex driver generates output for further processing by LaTeX, while the pstex driver generates
output for further processing by TeX. pslatex uses \specials understandable by dvips and xdvi. Figures
generated by pstex can be included in any plain-based format (including LaTeX).
Syntax:set terminal [pslatex | pstex] {default}
set terminal [pslatex | pstex]{rotate | norotate}{auxfile | noauxfile}{level1 | leveldefault | level3}{color | colour | monochrome}{background <rgbcolor> | nobackground}{dashlength | dl <DL>}{linewidth | lw <LW>} {pointscale | ps <PS>}{rounded | butt}{clip | noclip}{palfuncparam <samples>{,<maxdeviation>}}{size <XX>{unit},<YY>{unit}}{<font_size>}If you see the error message"Can't find PostScript prologue file ... "Please see and follow the instructions in postscript prologue (p. 292).
The option color enables color, while monochrome prefers black and white drawing elements. Further,monochrome uses gray palette but it does not change color of objects specified with an explicit colorspec.
dashlength or dl scales the length of dashed-line segments by <DL>, which is a floating-point number
greater than zero. linewidth or lw scales all linewidths by <LW>.
By default the generated PostScript code uses language features that were introduced in PostScript Level 2,
notably filters and pattern-fill of irregular objects such as filledcurves. PostScript Level 2 features are conditionally protected so that PostScript Level 1 interpreters do not issue errors but, rather, display a message
or a PostScript Level 1 approximation. The level1 option substitutes PostScript Level 1 approximationsof these features and uses no PostScript Level 2 code. This may be required by some old printers and old
versions of Adobe Illustrator. The flag level1 can be toggled later by editing a single line in the PostScript
output file to force PostScript Level 1 interpretation. In the case of files containing level 2 code, the above
features will not appear or will be replaced by a note when this flag is set or when the interpreting program
does not indicate that it understands level 2 PostScript or higher. The flag level3 enables PNG encoding
for bitmapped images, which can reduce the output size considerably.
rounded sets line caps and line joins to be rounded; butt is the default, butt caps and mitered joins.
clip tells PostScript to clip all output to the bounding box; noclip is the default.
palfuncparam controls how set palette functions are encoded as gradients in the output. Analytic
color component functions (set via set palette functions) are encoded as linear interpolated gradientsin the postscript output: The color component functions are sampled at <samples> points and all points
are removed from this gradient which can be removed without changing the resulting colors by more than<maxdeviation>. For almost every useful palette you may safely leave the defaults of <samples>=2000 and<maxdeviation>=0.003 untouched.
The default size for postscript output is 10 inches x 7 inches. The default for eps output is 5 x 3.5 inches.
The size option changes this to whatever the user requests. By default the X and Y sizes are taken to be in
inches, but other units are possibly (currently only cm). The BoundingBox of the plot is correctly adjusted
to contain the resized image. Screen coordinates always run from 0.0 to 1.0 along the full length of the plotedges as specified by the size option.

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if rotate is specified, the y-axis label is rotated. <font size> is the size (in pts) of the desired font.
If auxfile is specified, it directs the driver to put the PostScript commands into an auxiliary file instead of
directly into the LaTeX file. This is useful if your pictures are large enough that dvips cannot handle them.
The name of the auxiliary PostScript file is derived from the name of the TeX file given on the set output
command; it is determined by replacing the trailing .tex (actually just the final extent in the file name) with
.ps in the output file name, or, if the TeX file has no extension, .ps is appended. The .ps is included into
the .tex file by a \special{psfile=...} command. Remember to close the output file before next plot unlessin multiplot mode.
The pslatex driver offers a special way of controlling text positioning: (a) If any text string begins with ’{’,
you also need to include a ’}’ at the end of the text, and the whole text will be centered both horizontallyand vertically by LaTeX. (b) If the text string begins with ’[’, you need to continue it with: a position
specification (up to two out of t,b,l,r), ’]{’, the text itself, and finally, ’}’. The text itself may be anything
LaTeX can typeset as an LR-box. \rule{}{}’s may help for best positioning.
The options not described here are identical to the Postscript terminal. Look there if you want to knowwhat they do.
Examples:set term pslatex monochrome rotate# set to defaults

To write the PostScript commands into the file "foo.ps":
set term pslatex auxfile
set output "foo.tex"; plot ...; set output

About label positioning: Use gnuplot defaults (mostly sensible, but sometimes not really best):
set title '\LaTeX\ -- $ \gamma $'Force centering both horizontally and vertically:
set label '{\LaTeX\ -- $ \gamma $}' at 0,0Specify own positioning (top here):set xlabel '[t]{\LaTeX\ -- $ \gamma $}'The other label – account for long ticlabels:
set ylabel '[r]{\LaTeX\ -- $ \gamma $\rule{7mm}{0pt}}'

Linewidths and pointsizes may be changed with set style line.

Pstricks
The pstricks driver is intended for use with the "pstricks.sty" macro package for TeX or LaTeX. You need
"pstricks.sty", and, of course, a printer that understands PostScript, or a converter such as Ghostscript.
PSTricks is available at http://tug.org/PSTricks/.
This driver definitely does not come close to using the full capability of the PSTricks package.
Syntax:set terminal pstricks{unit | size <XX>{unit},<YY>{unit}}{standalone | input}{blacktext | colortext | colourtext}{linewidth <lw>} {rounded | butt}{pointscale <ps>}{psarrows | gparrows}{background <rgbcolor>}{pstricks | pdftricks2}

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The unit option produces a plot with internal dimensions 1x1. The default is a plot of size 5in,3in.
standalone produces a LaTeX file with possibly multiple plots, ready to be compiled. The default is input
to produce a TeX file which can be included.
blacktext forces all text to be written in black. colortext enables colored text. The default is blacktext.
rounded sets line caps and line joins to be rounded. butt sets butt caps and mitered joins and is thedefault.
linewidth and pointscale scale the width of lines and the size of point symbols, respectively.
psarrows draws arrows using PSTricks commands which are shorter but do not offer all options. gparrows
selects drawing arrows using gnuplot’s own routine for full functionality instead.
With the option pdftricks2 you can create output for the pdftricks2 macro package, which can be usedwith pdflatex/lualatex. Otherwise, output for the pstricks package with traditional tex/latex or xelatex is
produced.
The old hacktext option has been replaced by the new default format (%h), see format specifiers (p. 169).
Transparency requires support by Ghostscript or conversion to PDF.

Qt
The qt terminal device generates output in a separate window with the Qt library. Syntax:
set term qt {<n>}{size <width>,<height>}{position <x>,<y>}{title "title"}{font <font>} {{no}enhanced}{rounded|butt}{{no}replotonresize}{{no}antialias}{linewidth <lw>} {dashlength <dl>}{{no}persist} {{no}raise} {{no}ctrl}{close}{widget <id>}Multiple plot windows are supported: set terminal qt <n> directs the output to plot window number n.
The default window title is based on the window number. This title can also be specified with the keyword"title".
Plot windows remain open even when the gnuplot driver is changed to a different device. A plot window
can be closed by pressing the letter ’q’ while that window has input focus, by choosing close from a window
manager menu, or with set term qt <n> close.
The size of the plot area is given in pixels, it defaults to 640x480. In addition to that, the actual size of
the window also includes the space reserved for the toolbar and the status bar. When you resize a window,
the plot is immediately scaled to fit in the new size of the window. The qt terminal scales the whole plot,
including fonts and linewidths, and keeps its global aspect ratio constant. If you type replot, click the
replot icon in the terminal toolbar or type a new plot command, the new plot will completely fit in thewindow and the font size and the linewidths will be reset to their defaults.
The position option can be used to set the position of the plot window. The position option only applies tothe first plot after the set term command.
The active plot window (the one selected by set term qt <n>) is interactive. Its behaviour is shared withother terminal types. See mouse (p. 187) for details. It also has some extra icons, which are supposed to
be self-explanatory.
This terminal supports an enhanced text mode, which allows font and other formatting commands (subscripts, superscripts, etc.) to be embedded in labels and other text strings. The enhanced text mode syntax
is shared with other gnuplot terminal types. See enhanced (p. 34) for more details.

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gnuplot 6.0<font> is in the format "FontFace,FontSize", i.e. the face and the size comma-separated in a single string.
FontFace is a usual font face name, such as ’Arial’. If you do not provide FontFace, the qt terminal will use’Sans’. FontSize is the font size, in points. If you do not provide it, the qt terminal will use a size of 9 points.
For example :set term qt font "Arial,12"
set term qt font "Arial" # to change the font face only
set term qt font ",12" # to change the font size only
set term qt font "" # to reset the font name and size

The dashlength affects only custom dash patterns, not Qt’s built-in set.
To obtain the best output possible, the rendering involves three mechanisms : antialiasing, oversampling
and hinting. Oversampling combined with antialiasing provides subpixel accuracy, so that gnuplot can draw
a line from non-integer coordinates. This avoids wobbling effects on diagonal lines (’plot x’ for example).
Hinting avoids the blur on horizontal and vertical lines caused by oversampling. The terminal will snap theselines to integer coordinates so that a one-pixel-wide line will actually be drawn on one and only one pixel.
butt instructs the driver to use a line drawing method that does not overshoot the desired end point of aline. This setting is only applicable for line widths greater than 1. This setting is most useful when drawing
horizontal or vertical lines. Default is rounded.
The option replotonresize replots the data when the plot window is resized. Without this option, theeven-aspect-ratio scaling may result in the plot filling only part of the window after resizing. With thisoption, gnuplot does a full replot on each resize event, resulting in better space utilization. This option is
generally desirable, unless the potentially CPU-intensive replotting during resizing is a concern. Replots canbe manually initiated with hotkey ’e’ or the ’replot’ command.
By default, the window is raised to the top of your desktop when a plot is drawn. This can be controlledwith the keyword "raise". The keyword "persist" will prevent gnuplot from exiting before you explicitly
close all the plot windows.
The <space> key raises the gnuplot console window [MS Windows only]. The ’q’ key closes the plot window.
These hot keys can be changed to ctrl-space and ctrl-q using the terminal option keyword "{no}ctrl".
However the preferred way to select ctrl-q rather than ’q’ is to use the toggle in the tools widget of the plot
window.
The gnuplot outboard driver, gnuplot qt, is searched in a default place chosen when the program is compiled.
You can override that by defining the environment variable GNUPLOT DRIVER DIR.

Regis
Note: legacy terminal. The regis terminal device generates output in the REGIS graphics language. It has
the option of using 4 (the default) or 16 colors.
Syntax:set terminal regis {4 | 16}

Sixelgd
Syntax:set terminal sixelgd{{no}enhanced} {{no}truecolor} {rounded|butt}{linewidth <lw>} {dashlength <dl>}{tiny | small | medium | large | giant}{font "<face> {,<pointsize>}"} {fontscale <scale>}{size <x>,<y>} {anchor|scroll} {{no}transparent}{background <rgb_color>}

The sixel output format was originally used by DEC terminals and printers. The gnuplot sixelgd driverproduces a sixel output stream by converting a PNG image created internally using the gd library. The sixel

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output stream can be viewed in the terminal as it is created or it can be written to a file so that it can be
replayed later by echoing the file to the terminal.
The sixel terminal is also useful for displaying gnuplot graphics on the linux console when no windowing
system or graphics display manager is active. See linux console (p. 281).
The linewidth and dashlength options are scaling factors that affect all lines drawn. They are multipliedby values requested in drawing commands.
By default the sixel output uses 16 indexed colors. The truecolor option instead creates a 24-bit RGB png
image that is mapped down onto 256 colors in the output sixel image. Transparent fill styles require thetruecolor option. See fillstyle (p. 217).
butt instructs the driver to use a line drawing method that does not overshoot the desired end point of aline. This setting is only relevant for line widths greater than 1. The alternative is rounded, which produces
somewhat more uniform curved lines but can be much slower.
The details of font selection in the gdlib terminals are complicated. For more information please see fonts(p. 54).
The output plot size <x,y> is given in pixels. It defaults to 640x480, which is probably smaller than thesize of your terminal window.
transparent instructs the driver to make the background color transparent, but most terminal emulators
do not support this. Default is notransparent.
Gnuplot’s sixelgd output has been successfully tested with terminal emulators including konsole, mlterm,mintty, and the vt340 mode of xterm (note that distributed copies of xterm may not have been configured
to support sixel graphics). Sixel support in the KDE konsole terminal was added in version 22.04.0.
By default (anchor) each plot is drawn by overwriting the area at the top left of the window. This allows
redrawing to create an in-place animation and pseudo-mousing using the arrow keys during pause mouse.
The scroll option instead starts each plot at the current cursor position so that successive plots scroll withany intervening text.

Svg
This terminal produces files in the W3C Scalable Vector Graphics format.
Syntax:set terminal svg {size <x>,<y> {|fixed|dynamic}}{mouse} {standalone | jsdir <dirname>}{name <plotname>}{font "<fontname>{,<fontsize>}"} {{no}enhanced}{fontscale <multiplier>}{rounded|butt|square} {solid|dashed} {linewidth <lw>}{background <rgb_color>}

where <x> and <y> are the size of the SVG plot to generate, dynamic allows a svg-viewer to resize plot,
whereas the default setting, fixed, will request an absolute size.
linewidth <w> increases the width of all lines used in the figure by a factor of <w>.
<font> is the name of the default font to use (default Arial) and <fontsize> is the font size (in points,
default 12). SVG viewing programs may substitute other fonts when the file is displayed.
The enhanced text mode syntax is shared with other gnuplot terminal types. See enhanced (p. 34) for
more details.
The mouse option tells gnuplot to add support for mouse tracking and for toggling individual plots on/off
by clicking on the corresponding key entry. By default this is done by including a link that points to a script
in a local directory, usually /usr/local/share/gnuplot/<version>/js. You can change this by using the jsdir
option to specify either a different local directory or a general URL. The latter is usually appropriate if you
are embedding the svg into a web page. Alternatively, the standalone option embeds the mousing code in
the svg document itself rather than linking to an external resource.

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When an SVG file will be used in conjunction with external files, e.g. if it is referenced by javascript codein a web page or parent document, then a unique name is required to avoid potential conflicting references
to other SVG plots. Use the name option to ensure uniqueness.

Svga
Legacy terminal. The svga terminal driver supports PCs with SVGA graphics. It is typically only compiled
with DJGPP and uses the GRX graphics library. There is also a variant for Windows 32bit, which is mainly
used for debugging. The underlying library also supports X11, Linux console and SDL, but these targets are
currently not supported.
Syntax:set terminal svga {font "<fontname>"}{{no}enhanced}{background <rgb color>}{linewidth|lw <lw>}{pointscale|ps <scale>}{fontscale|fs <scale>}Enhanced text support can be activated using the enhanced option, see enhanced text (p. 34). Notethat changing the font size in enhanced text is currently not supported. Hence, super- and subscripts will
have the same size.
The linewidth parameter scales the width of lines. The pointscale parameter sets the scale factor for point
symbols. You can use fontscale to scale the bitmap font. This might be useful if you have a hi-res display.
Note that integer factors give best results.

Tek40
This family of terminal drivers supports a variety of VT-like terminals. tek40xx supports Tektronix 4010
and others as well as most TEK emulators. vttek supports VT-like tek40xx terminal emulators. The following are present only if selected when gnuplot is built: kc-tek40xx supports MS-DOS Kermit Tek4010
terminal emulators in color; km-tek40xx supports them in monochrome. selanar supports Selanar graphics. bitgraph supports BBN Bitgraph terminals. None have any options.

Tek410x
The tek410x terminal driver supports the 410x and 420x family of Tektronix terminals. It has no options.

Texdraw
The texdraw terminal driver supports the (La)TeX texdraw environment. It is intended for use with thetexdraw package, see https://www.ctan.org/tex-archive/graphics/texdraw/ .
set terminal texdraw{size <XX>{unit},<YY>{unit}}{standalone | input}{blacktext | colortext | colourtext}{linewidth <lw>} {rounded | butt}{pointscale <ps>}{psarrows | gparrows} {texpoints | gppoints}{background <rgbcolor>}

Note: Graphics are in grayscale only. Text is always black. Boxes and polygons are filled using solid graylevels only. Patterns are not available.
Points, among other things, are drawn using the LaTeX commands "\Diamond" and "\Box". These commands no longer belong to the LaTeX2e core; they are included in the latexsym package, which is part ofgnuplot 6.0299

the base distribution and thus part of any LaTeX implementation. Please do not forget to use this package.
Other point types use symbols from the amssymb package. For compatibility with plain TeX you need to
specify the gppoints option.
standalone produces a LaTeX file with possibly multiple plots, ready to be compiled. The default is input
to produce a TeX file which can be included.
blacktext forces all text to be written in black. colortext enables "colored" text. The default is blacktext
and "color" means grayscale really.
rounded sets line caps and line joins to be rounded; butt sets butt caps and mitered joins and is the default.
linewidth and pointscale scale the width of lines and the size of point symbols, respectively. pointscale
only applies to gppoints.
psarrows draws arrows using TeXdraw commands which are shorter but do not offer all options. gparrows
selects drawing arrows using gnuplot’s own routine for full functionality instead. Similarly, texpoints, andgppoints select LaTeX symbols or gnuplot’s point drawing routines.

Tgif
Legacy terminal (present only if gnuplot was configured –with-tgif). Tgif is/was an Xlib based interactive
2-D vector graphics drawing tool also capable of importing and marking up bitmap images.
The tgif driver supports a choice of font and font size and multiple graphs on the page. The proportions of
the axes are not changed.
Syntax:set terminal tgif {portrait | landscape | default} {<[x,y]>}{monochrome | color}{{linewidth | lw} <LW>}{solid | dashed}{font "<fontname>{,<fontsize>}"}where <[x,y]> specifies the number of graphs in the x and y directions on the page, color enables color,linewidth scales all linewidths by <LW>, "<fontname>" is the name of a valid PostScript font, and<fontsize> specifies the size of the PostScript font. defaults sets all options to their defaults: portrait,[1,1], color, linewidth 1.0, dashed, "Helvetica,18".
The solid option is usually preferred if lines are colored, as they often are in the editor. Hardcopy will beblack-and-white, so dashed should be chosen for that.
Multiplot is implemented in two different ways.
The first multiplot implementation is the standard gnuplot multiplot feature:
set terminal tgif
set output "file.obj"
set multiplot
set origin x01,y01
set size xs,ys
plot ...
...
set origin x02,y02
plot ...
unset multiplot

See set multiplot (p. 189) for further information.
The second version is the [x,y] option for the driver itself. The advantage of this implementation is thateverything is scaled and placed automatically without the need for setting origins and sizes; the graphs keep
their natural x/y proportions of 3/2 (or whatever is fixed by set size).
If both multiplot methods are selected, the standard method is chosen and a warning message is given.
Examples of single plots (or standard multiplot):300

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set terminal tgif
# defaults
set terminal tgif "Times-Roman,24"
set terminal tgif landscape
set terminal tgif landscape solid

Examples using the built-in multiplot mechanism:
set terminal tgif portrait [2,4]# portrait; 2 plots in the x# and 4 in the y-direction
set terminal tgif [1,2]# portrait; 1 plot in the x# and 2 in the y-direction
set terminal tgif landscape [3,3] # landscape; 3 plots in both# directions

Tikz
This driver creates output for use with the TikZ package of graphics macros in TeX. It is currently implemented via an external lua script, and set term tikz is a short form of the command set term lua tikz.
See term lua tikz (p. 281) for a complete description. Use the command set term tikz help to print
terminal options.

Tkcanvas
This terminal driver generates Tk canvas widget commands in one of the following scripting languages: Tcl(default), Perl, Python, Ruby, or REXX.
Syntax:set terminal tkcanvas {tcl | perl | perltkx | python | ruby | rexx}{standalone | input}{interactive}{rounded | butt}{nobackground | background <rgb color>}{{no}rottext}{size <width>,<height>}{{no}enhanced}{externalimages | pixels}

Execute the following sequence of Tcl/Tk commands to display the result:package require Tk# the following two lines are only required to support external images
package require img::png
source resize.tcl
source plot.tcl
canvas .c -width 800 -height 600
pack .cgnuplot .c

Or, for Perl/Tk use a program like this:use Tk;my $top = MainWindow->new;
my $c = $top->Canvas(-width => 800, -height => 600)->pack;my $gnuplot = do "plot.pl";$gnuplot->($c);
MainLoop;

Or, for Perl/Tkx use a program like this:use Tkx;
my $top = Tkx::widget->new(".");
my $c = $top->new_tk__canvas(-width => 800, -height => 600);$c->g_pack;my $gnuplot = do "plot.pl";$gnuplot->($c);
Tkx::MainLoop();gnuplot 6.0

301

Or, for Python/Tkinter use a program like this:from tkinter import *from tkinter import fontroot = Tk()
c = Canvas(root, width=800, height=600)
c.pack()exec(open('plot.py').read())
gnuplot(c)root.mainloop()

Or, for Ruby/Tk use a program like this:require 'tk'
root = TkRoot.new { title 'Ruby/Tk' }c = TkCanvas.new(root, 'width'=>800, 'height'=>600) { packload('plot.rb')
gnuplot(c)Tk.mainloop{ } }Or, for Rexx/Tk use a program like this:/**/call RxFuncAdd 'TkLoadFuncs', 'rexxtk', 'TkLoadFuncs'
call TkLoadFuncs
cv = TkCanvas('.c', '-width', 800, '-height', 600)
call TkPack cv
call 'plot.rex' cv
do forever
cmd = TkWait()
if cmd = 'AWinClose' then leave
interpret 'call' cmd
end

The code generated by gnuplot (in the above examples, this code is written to "plot.<ext>") contains thefollowing procedures:
gnuplot(canvas)
takes the name of a canvas as its argument.
When called, it clears the canvas, finds the size of the canvas anddraws the plot in it, scaled to fit.

gnuplot plotarea()
returns a list containing the borders of the plotting area
(xleft, xright, ytop, ybot) in canvas screen coordinates.

It works only for 2-dimensional plotting (`plot`).

gnuplot axisranges()returns the ranges of the two axes in plot coordinates(x1min, x1max, y1min, y1max, x2min, x2max, y2min, y2max).
It works only for 2-dimensional plotting (`plot`).

You can create self-contained, minimal scripts using the standalone option. The default is input which
creates scripts which have to be source’d (or loaded or called or whatever the adequate term is for the
language selected).
If the interactive option is specified, mouse clicking on a line segment will print the coordinates of its
midpoint to stdout. The user can supersede this behavior by supplying a procedure user gnuplot coordinates
which takes the following arguments:
win id x1s y1s x2s y2s x1e y1e x2e y2e x1m y1m x2m y2m,i.e. the name of the canvas and the id of the line segment followed by the coordinates of its start and end
point in the two possible axis ranges; the coordinates of the midpoint are only filled for logarithmic axes.
By default the canvas is transparent, but an explicit background color can be set with the background
option.
rounded sets line caps and line joins to be rounded; butt is the default: butt caps and mitered joins.

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Text at arbitrary angles can be activated with the rottext option, which requires Tcl/Tk 8.6 or later. The
default is norottext.
The size option tries to optimize the tic and font sizes for the given canvas size. By default an output sizeof 800 x 600 pixels is assumed.
enhanced selects enhanced text processing (default), but is currently only available for Tcl.
The pixels (default) option selects the failsafe pixel-by-pixel image handler, see also image pixels (p. 86).
The externalimages option saves images as external png images, which are later loaded and scaled by thetkcanvas code. This option is only available for Tcl and display may be slow in some situations since the Tk
image handler does not provide arbitrary scaling. Scripts need to source the provided rescale.tcl.
Interactive mode is not yet implemented for Python/Tk and Rexx/Tk. Interactive mode for Ruby/Tk does
not yet support user gnuplot coordinates.

Webp
The webp terminal generates either a single frame or an animation. The actual drawing is done via cairo,
a 2D graphics library, and pango, a library for laying out and rendering text.
Syntax:set term webp
{size <x_pixels>,<y_pixels>}{font <font>} {fontscale <scale>} {{no}enhanced}{{no}transparent} {background <rgbcolor>{linewidth <lw>} {rounded|butt|square} {dashlength <dl>}{pointscale <ps>}{{no}animate {quality <q>} {delay <msec>} {loop <n>}}Individual frames produced by the webp terminal are first created as 32-bit RGB + alpha channel images
using routines shared with the pngcairo terminal. See set term pngcairo (p. 288) for more details about
font and terminal options. The frames are then converted to webp format on output.
The animate option produces a webp file containing multiple frames, each one created by a separate plot or
splot command. The animation sequence is terminated by the next set output or set terminal command.
quality (1..100) affects the size of the output file. q values from 1 to 74 use lossy compression; smaller
values produce a smaller file at the cost of lost detail in the rendered image. q values from 75 to 100 use
lossless compression. All produce the same image quality (lossless!). Larger values spend more computing
time for diminishing benefit in reduced file size. The default is 75, lossless compression without excessive
computation.
The delay suboption sets the delay time in milliseconds between frames during playback (default 50 milliseconds).
The loop suboption specifies how many times the animation sequence should be repeated during playback.
The default (0) gives a continuous loop.

Windows
The windows terminal is a fast interactive terminal driver that uses the Windows GDI to draw and write
text. The cross-platform terminal wxt and terminal qt are also supported on Windows.
Syntax:set terminal windows {<n>}{color | monochrome}{solid | dashed}{rounded | butt}{enhanced | noenhanced}{font <fontspec>}

gnuplot 6.0

303{fontscale <scale>}{linewidth <scale>}{pointscale <scale>}{background <rgb color>}{title "Plot Window Title"}{{size | wsize} <width>,<height>}{position <x>,<y>}{docked {layout <rows>,<cols>} | standalone}{close}Multiple plot windows are supported: set terminal win <n> directs the output to plot window numbern.
color and monochrome select colored or mono output, dashed and solid select dashed or solid lines.
Note that color defaults to solid, whereas monochrome defaults to dashed. rounded sets line caps andline joins to be rounded; butt is the default, butt caps and mitered joins. enhanced enables enhanced text
mode features (subscripts, superscripts and mixed fonts, see enhanced text (p. 34) for more information).
<fontspec> is in the format "<fontface>,<fontsize>", where "<fontface>" is the name of a valid Windows
font, and <fontsize> is the size of the font in points and both components are optional. Note that in previous
versions of gnuplot the font statement could be left out and <fontsize> could be given as a number without
double quotes. This is no longer supported. linewidth, fontscale, pointscale can be used to scale thewidth of lines, the size of text, or the size of the point symbols. title changes the title of the graph window.
size defines the width and height of the window’s drawing area in pixels, wsize defines the actual size of
the window itself and position defines the origin of the window i.e. the position of the top left corner on
the screen (again in pixel). These options override any default settings from the wgnuplot.ini file.
docked embeds the graph window in the wgnuplot text window and the size and position options are
ignored. Note that docked is not available for console-mode gnuplot. Setting this option changes thedefault for new windows. The initial default is standalone. The layout option allows to reserve a minimal
number of columns and rows for graphs in docked mode. If there are more graphs than fit the given layout,
additional rows will be added. Graphs are sorted by the numerical id, filling rows first.
Other options may be changed using the graph-menu or the initialization file wgnuplot.ini.
The Windows version normally terminates immediately as soon as the end of any files given as commandline arguments is reached (i.e. in non-interactive mode), unless you specify - as the last command line
option. It will also not show the text-window at all, in this mode, only the plot. By giving the optional
argument -persist (same as for gnuplot under x11; former Windows-only options /noend or -noend arestill accepted as well), will not close gnuplot. Contrary to gnuplot on other operating systems, gnuplot’s
interactive command line is accessible after the -persist option.
The plot window remains open when the gnuplot terminal is changed with a set term command. The plot
window can be closed with set term windows close.
gnuplot supports different methods to create printed output on Windows, see windows printing (p. 304).
The windows terminal supports data exchange with other programs via clipboard and EMF files, see graphmenu (p. 303). You can also use the terminal emf to create EMF files.
Graph-menu
The gnuplot graph window has the following options on a pop-up menu accessed by pressing the rightmouse button(*) or selecting Options from the system menu or the toolbar:
Copy to Clipboard copies a bitmap and an enhanced metafile picture.
Save as EMF... allows the user to save the current graph window as enhanced metafile (EMF or EMF+).
Save as Bitmap... allows the user to save a copy of the graph as bitmap file.
Print... prints the graphics windows using a Windows printer driver and allows selection of the printer andscaling of the output. See also windows printing (p. 304).
Bring to Top when checked raises the graph window to the top after every plot.

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Color when checked enables color output. When unchecked it forces all grayscale output. This is e.g. usefulto test appearance of monochrome printouts.
The GDI backend which uses the classic GDI API is deprecated and has been disabled in this version.
GDI+ backend draws to the screen using the GDI+ Windows API. It supports full antialiasing, oversampling, transparency and custom dash patterns. This was the default in versions 5.0 and 5.2.
Direct2D backend uses Direct2D & DirectWrite APIs to draw. It uses graphic card acceleration and ishence typically much faster. Since Direct2D can not create EMF data, saving and copying to clipboard of
EMF data fall back to GDI+ while bitmap data is generated by D2d. This is the recommended and default
backend since version 5.3.
Oversampling draws diagonal lines at fractional pixel positions to avoid "wobbling" effects. Vertical or
horizontal lines are still snapped to integer pixel positions to avoid blurry lines.
Antialiasing enables smoothing of lines and edges. Note that this slows down drawing. Antialiasing ofpolygons is enabled by default but might slow down drawing with the GDI+ backend.
Fast rotation switches antialiasing temporarily off while rotating the graph with the mouse. This speeds
up drawing considerably at the expense of an additional redraw after releasing the mouse button.
Background... sets the window background color.
Choose Font... selects the font used in the graphics window.
Update wgnuplot.ini saves the current window locations, window sizes, text window font, text window fontsize, graph window font, graph window font size, background color to the initialization file wgnuplot.ini.
(*) Note that this menu is only available by pressing the right mouse button with unset mouse.

Printing
In order of preference, graphs may be printed in the following ways:
1. Use the gnuplot command set terminal to select a printer and set output to redirect output to a file.
2. Select the Print... command from the gnuplot graph window. An extra command screendump does
this from the text window.
3. If set output "PRN" is used, output will go to a temporary file. When you exit from gnuplot orwhen you change the output with another set output command, a dialog box will appear for you to select a
printer port. If you choose OK, the output will be printed on the selected port, passing unmodified throughthe print manager. It is possible to accidentally (or deliberately) send printer output meant for one printerto an incompatible printer.

Text-menu
The gnuplot text window has the following options on a pop-up menu accessed by pressing the right mousebutton or selecting Options from the system menu:
Copy to Clipboard copies marked text to the clipboard.
Paste copies text from the clipboard as if typed by the user.
Choose Font... selects the font used in the text window.
System Colors when selected makes the text window honor the System Colors set using the Control Panel.
When unselected, text is black or blue on a white background.
Wrap long lines when selected lines longer than the current window width are wrapped.
Update wgnuplot.ini saves the current settings to the initialisation file wgnuplot.ini, which is located in
the user’s application data directory.

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Wgnuplot.mnu
If the menu file wgnuplot.mnu is found in the same directory as gnuplot, then the menu specified in
wgnuplot.mnu will be loaded. Menu commands:[Menu][EndMenu][--][|][Button]starts a new menu with the name on the following line.
ends the current menu.
inserts a horizontal menu separator.
inserts a vertical menu separator.
puts the next macro on a push button instead of a menu.

Macros take two lines with the macro name (menu entry) on the first line and the macro on the second line.
Leading spaces are ignored. Macro commands:[INPUT][EOS][OPEN]

Input string with prompt terminated by [EOS] or {ENTER}
End Of String terminator. Generates no output.
Get name of a file to open, with the title of the dialog
terminated by [EOS], followed by a default filename terminatedby [EOS] or {ENTER}.
[SAVE]
Get name of a file to save. Parameters like [OPEN][DIRECTORY] Get name of a directory, with the title of the dialog
terminated by [EOS] or {ENTER}

Macro character substitutions:{ENTER}
{TAB}
{ESC}
{^A}
...
{^_}

Carriage Return '\r'
Tab '\011'
Escape '\033''\001''\031'

Macros are limited to 256 characters after expansion.
Wgnuplot.ini
The Windows text window and the windows terminal will read some of their options from the [WGNUPLOT] section of wgnuplot.ini. This file is located in the user’s application data directory. Here’s asample wgnuplot.ini file:[WGNUPLOT]TextOrigin=0 0
TextSize=640 150
TextFont=Consolas,9TextWrap=1
TextLines=400
TextMaximized=0
SysColors=0
GraphOrigin=0 150
GraphSize=640 330
GraphFont=Tahoma,10GraphColor=1
GraphToTop=1
GraphGDI+=1
GraphD2D=0
GraphGDI+Oversampling=1
GraphAntialiasing=1
GraphPolygonAA=1
GraphFastRotation=1
GraphBackground=255 255 255
DockVerticalTextFrac=350
DockHorizontalTextFrac=400

These settings apply to the wgnuplot text-window only. The TextOrigin and TextSize entries specify thelocation and size of the text window. If TextMaximized is non-zero, the window will be maximized.
The TextFont entry specifies the text window font and size.

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The TextWrap entry selects wrapping of long text lines.
The TextLines entry specifies the number of (unwrapped) lines the internal buffer of the text window canhold. This value currently cannot be changed from within wgnuplot.
See text-menu (p. 304).
DockVerticalTextFrac and DockHorizontalTextFrac set the fraction of the window reserved for the
text window in permille of the vertical or horizontal layout.
The GraphFont entry specifies the font name and size in points.
See graph-menu (p. 303).

Wxt
The wxt terminal device generates output in a separate window. The window is created by the wxWidgets
library, where the ’wxt’ comes from. The actual drawing is done via cairo, a 2D graphics library, and pango,
a library for laying out and rendering text.
Syntax:set term wxt {<n>}{size <width>,<height>} {position <x>,<y>}{background <rgb_color> | nobackground}{{no}enhanced}{font <font>} {fontscale <scale>}{title "title"}{linewidth <lw>} {butt|rounded|square}{dashlength <dl>}{{no}persist}{{no}raise}{{no}ctrl}{close}Multiple plot windows are supported: set terminal wxt <n> directs the output to plot window numbern.
The default window title is based on the window number. This title can also be specified with the keyword"title".
Plot windows remain open even when the gnuplot driver is changed to a different device. A plot window
can be closed by pressing the letter ’q’ while that window has input focus, by choosing close from a window
manager menu, or with set term wxt <n> close.
The size of the plot area is given in pixels, it defaults to 640x384. In addition to that, the actual size of thewindow also includes the space reserved for the toolbar and the status bar. When you resize a window, theplot is immediately scaled to fit in the new size of the window. Unlike other interactive terminals, the wxt
terminal scales the whole plot, including fonts and linewidths, and keeps its global aspect ratio constant,leaving an empty space painted in gray. If you type replot, click the replot icon in the terminal toolbar
or type a new plot command, the new plot will completely fit in the window and the font size and thelinewidths will be reset to their defaults.
The position option can be used to set the position of the plot window. The position option only applies tothe first plot after the set term command.
The active plot window (the one selected by set term wxt <n>) is interactive. Its behaviour is sharedwith other terminal types. See mouse (p. 187) for details. It also has some extra icons, which are supposed
to be self-explanatory.
This terminal supports an enhanced text mode, which allows font and other formatting commands (subscripts, superscripts, etc.) to be embedded in labels and other text strings. The enhanced text mode syntax
is shared with other gnuplot terminal types. See enhanced (p. 34) for more details.
<font> is in the format "FontFace,FontSize", i.e. the face and the size comma-separated in a single string.
FontFace is a usual font face name, such as ’Arial’. If you do not provide FontFace, the wxt terminal will

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307

use ’Sans’. FontSize is the font size, in points. If you do not provide it, the wxt terminal will use a size of
10 points.
For example :set term wxt font "Arial,12"
set term wxt font "Arial" # to change the font face only
set term wxt font ",12" # to change the font size only
set term wxt font "" # to reset the font name and size

The fonts are retrieved from the usual fonts subsystems. Under Windows, those fonts are to be found andconfigured in the entry "Fonts" of the control panel. Under UNIX, they are handled by "fontconfig".
Pango, the library used to layout the text, is based on utf-8. Thus, the wxt terminal has to convert fromyour encoding to utf-8. The default input encoding is based on your ’locale’. If you want to use anotherencoding, make sure gnuplot knows which one you are using. See encoding (p. 166) for more details.
Pango may give unexpected results with fonts that do not respect the unicode mapping. With the Symbol
font, for example, the wxt terminal will use the map provided by http://www.unicode.org/ to translatecharacter codes to unicode. Pango will do its best to find a font containing this character, looking for yourSymbol font, or other fonts with a broad unicode coverage, like the DejaVu fonts. Note that "the Symbol.PFB".
font" is to be understood as the Adobe Symbol font, distributed with Acrobat Reader as "SY
Alternatively, the OpenSymbol font, distributed with OpenOffice.org as "opens .ttf", offers the same characters. Microsoft has distributed a Symbol font ("symbol.ttf"), but it has a different character set withseveral missing or moved mathematic characters. If you experience problems with your default setup (ifthe demo enhancedtext.dem is not displayed properly for example), you probably have to install one of
the Adobe or OpenOffice Symbol fonts, and remove the Microsoft one. Other non-conform fonts, such as"wingdings" have been observed working.
The rendering of the plot can be altered with a dialog available from the toolbar. To obtain the best output
possible, the rendering involves three mechanisms : antialiasing, oversampling and hinting. Antialiasing
allows to display non-horizontal and non-vertical lines smoother. Oversampling combined with antialiasing
provides subpixel accuracy, so that gnuplot can draw a line from non-integer coordinates. This avoids
wobbling effects on diagonal lines (’plot x’ for example). Hinting avoids the blur on horizontal and verticallines caused by oversampling. The terminal will snap these lines to integer coordinates so that a one-pixelwide line will actually be drawn on one and only one pixel.
By default, the window is raised to the top of your desktop when a plot is drawn. This can be controlledwith the keyword "raise". The keyword "persist" will prevent gnuplot from exiting before you explicitly
close all the plot windows. Finally, by default the key <space> raises the gnuplot console window, and ’q’
closes the plot window. The keyword "ctrl" allows you to replace those bindings by <ctrl>+<space> and<ctrl>+’q’, respectively. These three keywords (raise, persist and ctrl) can also be set and remembered
between sessions through the configuration dialog.

X11
Syntax:set terminal x11 {<n> | window "<string>"}{title "<string>"}{{no}enhanced} {font <fontspec>}{linewidth LW}{{no}persist} {{no}raise} {{no}ctrlq}{{no}replotonresize}{close}{size XX,YY} {position XX,YY}
set terminal x11 {reset}

Multiple plot windows are supported: set terminal x11 <n> directs the output to plot window number
n. If n is not 0, the terminal number will be appended to the window title (unless a title has been supplied
manually) and the icon will be labeled Gnuplot <n>. The active window may be distinguished by a change
in cursor (from default to crosshair).

308

gnuplot 6.0

The x11 terminal can connect to X windows previously created by an outside application via the option
window followed by a string containing the X ID for the window in hexadecimal format. Gnuplot uses thatexternal X window as a container since X does not allow for multiple clients selecting the ButtonPress event.
In this way, gnuplot’s mouse features work within the contained plot window.
set term x11 window "220001e"

The x11 terminal supports enhanced text mode (see enhanced (p. 34)), subject to the available fonts. In
order for font size commands embedded in text to have any effect, the default x11 font must be scalable.
Thus the first example below will work as expected, but the second will not.
set term x11 enhanced font "arial,15"
set title '{/=20 Big} Medium {/=5 Small}'set term x11 enhanced font "terminal-14"
set title '{/=20 Big} Medium {/=5 Small}'Plot windows remain open even when the gnuplot driver is changed to a different device. A plot window
can be closed by pressing the letter q while that window has input focus, or by choosing close from awindow manager menu. All plot windows can be closed by specifying reset, which actually terminates the
subprocess which maintains the windows (unless -persist was specified). The close command can be used
to close individual plot windows by number. However, after a reset, those plot windows left due to persist
cannot be closed with the command close. A close without a number closes the current active plot window.
The gnuplot outboard driver, gnuplot x11, is searched in a default place chosen when the program is compiled.
You can override that by defining the environment variable GNUPLOT DRIVER DIR to point to a different
location.
Plot windows will automatically be closed at the end of the session unless the -persist option was given.
The options persist and raise are unset by default, which means that the defaults (persist == no and raise== yes) or the command line options -persist / -raise or the Xresources are taken. If [no]persist or [no]raiseare specified, they will override command line options and Xresources. Setting one of these options takes
place immediately, so the behaviour of an already running driver can be modified. If the window does not
get raised, see discussion in raise (p. 146).
The option replotonresize (active by default) replots the data when the plot window is resized. Without
this option, the even-aspect-ratio scaling may result in the plot filling only part of the window after resizing.
With this option, gnuplot does a full replot on each resize event, resulting in better space utilization. This
option is generally desirable, unless the potentially CPU-intensive replotting during resizing is a concern.
Replots can be manually initiated with hotkey ’e’ or the ’replot’ command.
The option title "<title name>" will supply the title name of the window for the current plot window orplot window <n> if a number is given. Where (or if) this title is shown depends on your X window manager.
The size option can be used to set the size of the plot window. The size option will only apply to newly
created windows.
The position option can be used to set the position of the plot window. The position option will only apply
to newly created windows.
The size or aspect ratio of a plot may be changed by resizing the gnuplot window.
Linewidths and pointsizes may be changed from within gnuplot with set linestyle.
For terminal type x11, gnuplot accepts (when initialized) the standard X Toolkit options and resources
such as geometry, font, and name from the command line arguments or a configuration file. See the X(1)man page (or its equivalent) for a description of such options.
A number of other gnuplot options are available for the x11 terminal. These may be specified either as
command-line options when gnuplot is invoked or as resources in the configuration file ".Xdefaults". They
are set upon initialization and cannot be altered during a gnuplot session. (except persist and raise)gnuplot 6.0

309

X11 fonts
Upon initial startup, the default font is taken from the X11 resources as set in the system or user .Xdefaults
file or on the command line.
Example:gnuplot*font: lucidasans-bold-12

A new default font may be specified to the x11 driver from inside gnuplot using`set term x11 font "<fontspec>"`

The driver first queries the X-server for a font of the exact name given. If this query fails, then it tries tointerpret <fontspec> as "<font>,<size>,<slant>,<weight>" and to construct a full X11 font name of theform-*-<font>-<weight>-
-*-*-<size>-*-*-*-*-*-<encoding><font> is the base name of the font (e.g. Times or Symbol)<size> is the point size (defaults to 12 if not specified)
 is 'i' if <slant>=="italic" 'o' if <slant>=="oblique" 'r' otherwise<weight> is 'medium' or 'bold' if explicitly requested, otherwise '*'<encoding> is set based on the current character set.

So set term x11 font "arial,15,italic" will be translated to -*-arial-*-i-*-*-15-*-*-*-*-*-iso8859-1 (assuming default encoding). The <size>, <slant>, and <weight> specifications are all optional. If you do not
specify <slant> or <weight> then you will get whatever font variant the font server offers first. You may
set a default encoding via the corresponding X11 resource. E.g.
gnuplot*encoding: iso8859-15

The driver also recognizes some common PostScript font names and replaces them with possible X11 or
TrueType equivalents. This same sequence is used to process font requests from set label.
If your gnuplot was built with configuration option –enable-x11-mbfonts, you can specify multi-byte fonts
by using the prefix "mbfont:" on the font name. An additional font may be given, separated by a semicolon.
Since multi-byte font encodings are interpreted according to the locale setting, you must make sure that theenvironmental variable LC CTYPE is set to some appropriate locale value such as ja JP.eucJP, ko KR.EUC,
or zh CN.EUC.
Example:set term x11 font 'mbfont:kana14;k14'# 'kana14' and 'k14' are Japanese X11 font aliases, and ';'# is the separator of font names.
set term x11 font 'mbfont:fixed,16,r,medium'# <font>,<size>,<slant>,<weight> form is also usable.
set title '(mb strings)' font 'mbfont:*-fixed-medium-r-normal--14-*'The same syntax applies to the default font in Xresources settings, for example,
gnuplot*font: \mbfont:-misc-fixed-medium-r-normal--14-*-*-*-c-*-jisx0208.1983-0

If gnuplot is built with –enable-x11-mbfonts, you can use two special PostScript font names ’Ryumin-Light-*’and ’GothicBBB-Medium-*’ (standard Japanese PS fonts) without the prefix "mbfont:".
Command-line options
In addition to the X Toolkit options, the following options may be specified on the command line whenstarting gnuplot or as resources in your ".Xdefaults" file (note that raise and persist can be overridden
later by set term x11 [no]raise [no]persist):310

gnuplot 6.0‘-mono‘‘-gray‘‘-clear‘‘-tvtwm‘‘-raise‘‘-noraise‘‘-persist‘forces monochrome rendering on color displays.
requests grayscale rendering on grayscale or color displays.
(Grayscale displays receive monochrome rendering by default.)
requests that the window be cleared momentarily before a
new plot is displayed.
requests that geometry specifications for position of thewindow be made relative to the currently displayed portionof the virtual root.
raises plot window after each plot.
does not raise plot window after each plot.
plot windows survive after main gnuplot program exits.

The options are shown above in their command-line syntax. When entered as resources in ".Xdefaults",
they require a different syntax.
Example:gnuplot*gray: on
gnuplot*ctrlq: on

gnuplot also provides a command line option (-pointsize <v>) and a resource, gnuplot*pointsize: <v>,
to control the size of points plotted with the points plotting style. The value v is a real number (greaterthan 0 and less than or equal to ten) used as a scaling factor for point sizes. For example, -pointsize 2 uses
points twice the default size, and -pointsize 0.5 uses points half the normal size.
The -ctrlq switch changes the hot-key that closes a plot window from q to <ctrl>q. This is useful is you areusing the keystroke-capture feature pause mouse keystroke, since it allows the character q to be captured
just as all other alphanumeric characters. The -ctrlq switch similarly replaces the <space> hot-key with<ctrl><space> for the same reason.
Color resources
NB: THIS SECTION IS LARGELY IRRELEVANT IN GNUPLOT VERSION 5 The X11 terminal honors
the following resources (shown here with their default values) or the greyscale resources. The values may becolor names as listed in the X11 rgb.txt file on your system, hexadecimal RGB color specifications (see X11
documentation), or a color name followed by a comma and an intensity value from 0 to 1. For example,
blue, 0.5 means a half intensity blue.
gnuplot*background: whitegnuplot*textColor: black
gnuplot*borderColor: black
gnuplot*axisColor: black
gnuplot*line1Color: red
gnuplot*line2Color: green
gnuplot*line3Color: blue
gnuplot*line4Color: magenta
gnuplot*line5Color: cyan
gnuplot*line6Color: sienna
gnuplot*line7Color: orange
gnuplot*line8Color: coral
The command-line syntax for these is simple only for background, which maps directly to the usual X11
toolkit option "-bg". All others can only be set on the command line by use of the generic "-xrm" resource
override option
Examples:gnuplot -background coralgnuplot 6.0311

to change the background color.
gnuplot -xrm 'gnuplot*line1Color:blue'

to override the first linetype color.

Grayscale resources
When -gray is selected, gnuplot honors the following resources for grayscale or color displays (shown herewith their default values). Note that the default background is black.

gnuplot*background: black
gnuplot*textGray: whitegnuplot*borderGray: gray50
gnuplot*axisGray: gray50
gnuplot*line1Gray: gray100
gnuplot*line2Gray: gray60
gnuplot*line3Gray: gray80
gnuplot*line4Gray: gray40
gnuplot*line5Gray: gray90
gnuplot*line6Gray: gray50
gnuplot*line7Gray: gray70
gnuplot*line8Gray: gray30

Line resources
NB: THIS SECTION IS LARGELY IRRELEVANT IN GNUPLOT VERSION 5 gnuplot honors the following resources for setting the width (in pixels) of plot lines (shown here with their default values.) 0 or 1means a minimal width line of 1 pixel width. A value of 2 or 3 may improve the appearance of some plots.

gnuplot*borderWidth: 1
gnuplot*axisWidth: 0
gnuplot*line1Width: 0
gnuplot*line2Width: 0
gnuplot*line3Width: 0
gnuplot*line4Width: 0
gnuplot*line5Width: 0
gnuplot*line6Width: 0
gnuplot*line7Width: 0
gnuplot*line8Width: 0

gnuplot honors the following resources for setting the dash style used for plotting lines. 0 means a solid line.
A two-digit number jk (j and k are >= 1 and <= 9) means a dashed line with a repeated pattern of j pixels
on followed by k pixels off. For example, ’16’ is a dotted line with one pixel on followed by six pixels off.
More elaborate on/off patterns can be specified with a four-digit value. For example, ’4441’ is four on, four
off, four on, one off. The default values shown below are for monochrome displays or monochrome renderingon color or grayscale displays. Color displays default to dashed:offgnuplot*dashed: off
gnuplot*borderDashes: 0
gnuplot*axisDashes: 16
gnuplot*line1Dashes: 0
gnuplot*line2Dashes: 42
gnuplot*line3Dashes: 13
gnuplot*line4Dashes: 44
gnuplot*line5Dashes: 15
gnuplot*line6Dashes: 4441
gnuplot*line7Dashes: 42
gnuplot*line8Dashes: 13

X11 pm3d resources
NB: THIS SECTION IS LARGELY IRRELEVANT IN GNUPLOT VERSION 5
By default gnuplot uses the default visual of the screen. The number of colors which can be allocateddepends on the visual class chosen. On a visual class with a depth > 12bit, gnuplot starts with a maximal
number of 0x200 colors. On a visual class with a depth > 8bit (but <= 12 bit) the maximal number ofcolors is 0x100, on <= 8bit displays the maximum number of colors is 240 (16 are left for line colors).
Gnuplot first starts to allocate the maximal number of colors as stated above. If this fails, the number ofcolors is reduced by the factor 2 until gnuplot gets all colors which are requested. If dividing maxcolors by 2
repeatedly results in a number which is smaller than mincolors gnuplot tries to install a private colormap.
In this case the window manager is responsible for swapping colormaps when the pointer is moved in andout the x11 driver’s window.
The default for mincolors is maxcolors / (num colormaps > 1 ? 2 : 8), where num colormaps is the numberof colormaps which are currently used by gnuplot (usually 1, if only one x11 window is open).

X11 other resources
By default the contents of the current plot window are exported to the X11 clipboard in response to X eventsin the window. Setting the resource ’gnuplot*exportselection’ to ’off’ or ’false’ will disable this.
By default text rotation is done using a method that is fast, but can corrupt nearby colors depending on the
background. If this is a problem, you can set the resource ’gnuplot.fastrotate’ to ’off’

gnuplot*exportselection: off
gnuplot*fastrotate: on
gnuplot*ctrlq: off

Xlib
The xlib terminal driver supports the X11 Windows System. It generates gnuplot x11 commands, but sends
them to the output file specified by set output ’<filename>’. set term x11 is equivalent to set output"|gnuplot x11 -noevents"; set term xlib. xlib takes the same set of options as x11.

312

INDEX

gnuplot 6.0

Part V

Index
Index’ ’, 134’+’, 134’++’, 134++, 141.gnuplot, 64
1D, 227
2D, 227, 229
3D, 99abs, 39
acos, 39
acosh, 39
acsplines, 132
adobeglyphnames, 292
Ai, 43, 45
aifm, 257
airy, 39
all, 146
alpha channel, 42, 86, 155Amos, 45
angles, 37, 93, 149, 210
animate, 101, 277
animation, 101
aqua, 257
arg, 37, 39
ARGV, 103, 114
argv, 103
arrays, 26, 29, 52, 130, 137
arrow, 150, 216
arrows, 29, 71, 95
arrowstyle, 95, 150, 215
asin, 39
asinh, 39
atan, 39
atan2, 39
atanh, 39
automated, 85
autoscale, 151
autotitle, 34, 161, 177avs, 123
axes, 33, 63, 120
azimuth, 187, 229
back, 60
background, 58, 60
backquotes, 66, 253bars, 72, 74, 166
batch/interactive, 23, 31, 105, 118, 149
BE, 257
be, 257
beeswarm, 72, 175
behind, 60
besi0, 39
besi1, 39
besin, 39
besj0, 39
besj1, 39
besjn, 39
BesselH1, 25, 43
BesselH2, 43
BesselI, 43, 45
BesselJ, 43, 45
BesselK, 25, 43, 45
BesselY, 43, 45
besy0, 39
besy1, 39
besyn, 39bezier, 132
bgnd, 58, 60
Bi, 43, 45
binary, 121, 123bind, 61, 119, 148, 152, 188bins, 29, 128, 132
bitwise operators, 49
black, 58, 60
block, 55, 260
blocks, 24, 52, 56, 103, 104, 118, 148bmargin, 152bold, 34
border, 79, 153, 172, 217, 224, 236
boxdepth, 74, 154
boxed, 221
boxerrorbars, 72, 154
boxes, 29, 72, 75, 154
boxplot, 74, 76, 217
boxwidth, 72, 74, 76, 154
boxxyerror, 75
branch, 111
break, 102, 104, 256
broken axis, 193bugs, 23313

314
caca, 261, 262
cairolatex, 262, 281
call, 31, 102, 117
candlesticks, 74, 75, 80, 217
canvas, 32, 276, 279, 288
canvas terminal, 264
cardinality, 49, 52
cbdata, 241
cbdtics, 241
cblabel, 243
cbmtics, 243
cbrange, 57, 58, 155, 205, 207, 219, 243
cbrt, 39
cbtics, 243
cd, 102
cdawson, 40, 45
ceil, 42center, 86, 124cerf, 40, 45
cgm, 265
chi shapes, 155
circle, 76, 195
circles, 29, 76
clabel, 156
clear, 103
clip, 95, 156
clip1in, 208
clip4in, 208
clipcb, 208
clipping, 99
close, 63
CMY, 202
cnormal, 133
cntrlabel, 63, 156, 159, 160, 176
cntrparam, 63, 157, 160, 213, 250
color assignment, 206
colorbox, 58, 159, 198, 205, 207, 243
colormap, 26, 59, 155, 201
colornames, 57, 160, 219, 244, 276
colors, 29, 56, 57, 82, 155, 156, 199, 219
colorsequence, 155colorspec, 57, 78, 85, 86, 91, 144, 181, 194, 199,
209, 219, 220, 227
column, 47, 136
columnhead, 47, 126
columnheader, 34, 126, 136, 142, 161, 177, 252
columnheaders, 126, 161
command line editing, 32
command line options, 31
command-line-editing, 147
command-line-options, 23
commands, 102comments, 23, 33
commentschars, 33, 163

gnuplot 6.0

INDEX

complex, 37
concavehull, 25, 26, 129, 155conj, 39
console, 281, 297
constants, 38
context, 268, 281
continue, 102, 104, 256
contour, 63, 99, 159, 160, 172, 222, 250
contourfill, 25, 77, 160
contours, 160
conversion, 42
convexhull, 25, 128
coordinates, 33, 150, 175, 179–181, 194–196, 204,
215, 225, 227, 232, 236
copyright, 22
cornerpoles, 161
corners2color, 209cos, 39
cosh, 39
counting words, 48
csplines, 26, 132
csv, 223
cubehelix, 201
cumulative, 133
cycle, 183
dashtype, 57, 59, 161data, 120, 124, 212, 222
data file, 124
datablocks, 55, 124, 135
datafile, 63, 105, 124, 126, 151, 160, 172, 249
datastrings, 34, 142
date specifiers, 170
Dawson’s integral, 40
debug, 270
decimalsign, 163, 166, 169, 184
defined, 37
degrees, 149
demos, 31
depthorder, 99, 207, 208
dgrid3d, 81, 95, 164, 211, 213, 222, 250
division, 36
do, 56, 104, 117, 256
domterm, 270
dots, 77
dpu414, 275
dumb, 260, 270
dummy, 165
dx, 86, 124dxf, 271
dy, 86, 124edf, 123
editing, 32

INDEX

gnuplot 6.0

editing postscript, 291
eepic, 29, 281
ehf, 123
ellipse, 78, 93, 195, 221
ellipses, 78, 221
elliptic, 42
elliptic integrals, 42
EllipticE, 39
EllipticK, 39
EllipticPi, 39
emf, 271
emtex, 29, 281
encoding, 35, 36, 54, 66, 166, 184, 186, 285, 289,
307
encodings, 166
enhanced, 34, 257, 280, 285, 288, 289, 295, 297,
306, 308
environment, 36
epidemiological week, 46, 47
epoch, 46
eps, 54
epscairo, 272
epslatex, 272, 281
epson 180dpi, 275
epson 60dpi, 275
epson lx800, 275
equal, 214
equal axes, 229
erf, 39
erfc, 39
erfi, 40, 45
error estimates, 108error recovery, 27error state, 51, 148errorbars, 74–76, 80, 97, 166errorlines, 98
errors, 51
errorscaling, 110
evaluate, 104every, 126, 251
example, 127
examples, 31
exists, 42, 66
exit, 105, 146
exp, 39
expint, 25, 43, 45
exponentiation, 49
expressions, 36, 145, 244
factorial, 49
faddeeva, 40, 45
FAQ, 23
faq, 23fc, 217315

fenceplots, 100, 101fig, 275
file, 124
filetype, 86, 123
fill, 73, 75, 76, 79, 82, 101
fillcolor, 57, 99, 206, 208, 217
filledcurves, 26, 78
fillsteps, 80
fillstyle, 74, 75, 78, 143, 194, 217, 220, 280, 288,
297
filter, 137, 251
filters, 25, 128, 131
financebars, 75, 79, 217
fit, 36, 51, 105, 107, 108, 111, 136, 168
FIT LOG, 110
fit parameters, 107
FIT SCRIPT, 110
fitting, 108fix, 152
flipx, 86, 124
flipy, 124flipz, 124
floating point exceptions, 162
floor, 42
flush, 208
fnormal, 133fontconfig, 54
fontfile, 55, 290, 291, 293
fontpath, 168
fonts, 36, 54, 279, 288, 297, 309
for, 56, 83, 85, 117, 149, 254
format, 168, 222, 226, 232, 233, 237
format specifiers, 169
fortran, 162
fpe trap, 162
frequency, 128, 133
FresnelC, 25, 43
FresnelS, 43
front, 60
fsteps, 80
ftriangles, 208
function, 138
functionblocks, 114, 161
functions, 52, 120, 138
gamma, 44
gamma correction, 202
gd, 54, 277
general, 121, 163, 202, 249
geographic, 238
geomean, 209
gif, 54, 276
global, 64
glossary, 55

316
gnuplot, 22
gnuplot defined, 51
gnuplotrc, 64
gpic, 277
gprintf, 65, 169, 180, 186
GPVAL, 51
gpval, 51
gradient, 204graph menu, 303
graph-menu, 303, 306
grass, 278
gray, 187
grayscale resources, 311
grid, 25, 81, 85, 93, 95, 171, 212, 227
grid data, 160, 164, 222, 246, 249
GridDistance, 255
Hankel, 43, 45
harmean, 209
heatmap, 25
heatmaps, 81, 86, 93
help, 116
help desk, 23
hexadecimal, 38
hidden3d, 99, 172, 174
histeps, 80
histogram, 133
histograms, 82, 218
history, 116, 147
hotkey, 61
hotkeys, 23, 61
hpgl, 278
HSV, 202hsv, 42, 57
hsv2rgb, 42
hypertext, 87, 182
ibeta, 24, 44
if, 56, 104, 116
igamma, 24, 44, 47
imag, 39
image, 81, 85, 91, 92
imagen, 279
import, 64, 117
impulses, 87
index, 53, 125, 130, 251
initialization, 31, 64, 148inline, 55
inset, 63, 103, 189
int, 42integer, 29, 42
interval, 218
introduction, 22
inverf, 39

gnuplot 6.0

INDEX

invibeta, 24, 44
invigamma, 24, 44
invnorm, 39
isosamples, 63, 138, 173, 174, 213, 227, 229, 249,
250
isosurface, 29, 100
isotropic, 93, 174, 214, 229
italic, 34
iterate, 56, 147
iteration, 56, 104, 117, 141, 149, 254
iteration specifier, 56
jitter, 29, 72, 175, 250
join, 26, 48
jpeg, 54, 279
kdensity, 26, 128, 134, 164
keepfix, 152
key, 94, 142, 143, 175
keyentry, 29, 85, 94, 176, 177
keys, 178
kittycairo, 27, 101, 280
kittygd, 280
label, 87, 180, 222labels, 34, 87, 126, 181, 187
LambertW, 25, 44
lambertw, 39
latex, 29, 34, 281
layers, 60, 194
layout, 28, 175, 189lc, 57
least squares, 105legend, 175, 179
lgamma, 40
libcerf, 45
libopenspecfun, 45
license, 22
lighting, 29, 207, 209
limit, 108line, 159, 171, 215, 242
line editing, 32
linecolor, 57, 72, 75, 79, 95
lines, 88linespoints, 60, 88, 218
linestyle, 88, 218
linetype, 57, 155, 156, 218, 219
linetypes, 56, 88, 90, 144
linewidth, 88, 218
link, 139, 151, 183, 231, 234, 240
linux console, 281
list, 236
lmargin, 183
lnGamma, 25, 44, 45load, 117

INDEX
loadpath, 184
local, 24, 64, 114, 118
locale, 54, 163, 166, 184log, 40, 154
log10, 40
logit, 193
logscale, 184, 239
lower, 146
lp, 88lua, 281
macros, 52, 66, 104map, 99, 210, 246
mapping, 63, 185, 210
margin, 152, 183, 190, 212, 227
margins, 185
markup, 34
Marquardt, 105mask, 26, 130, 144
masking, 81, 89, 129, 130
matrix, 121, 127, 163, 246, 252max, 209
maxiter, 108
mcsplines, 132
mean, 209
median, 209
micro, 186
min, 209minussign, 186
missing, 47, 137, 162
mixing macros backquotes, 67
model, 199
modulo, 49
modulus, 39
monochrome, 57, 155, 186
mouse, 61, 62, 187, 295, 306
mouseformat, 188
mousewheel, 188
mousing, 23, 187
mttics, 189
multi branch, 111
multi-branch, 106
multiplot, 63, 104, 147, 189, 299
multiplots, 30, 147, 187, 191
mx2tics, 191
mxtics, 189, 191, 192, 213
my2tics, 192
mytics, 192
mztics, 192
NaN, 37, 52, 137
nec cp6, 275
negation, 49
new, 24

gnuplot 6.0
newhistogram, 82, 84
newspiderplot, 94
noarrow, 150
noautoscale, 151
noborder, 153
nocbdtics, 241
nocbmtics, 243
nocbtics, 243
noclipcb, 208
nocontour, 160
nodgrid3d, 164
nodraw, 60
noextend, 152, 196, 234, 235
nofpe trap, 162
nogrid, 164
nohidden3d, 172
nokey, 175
nolabel, 180
nologscale, 184
nomouse, 187
nomttics, 189
nomultiplot, 189
nomx2tics, 191
nomxtics, 191
nomy2tics, 192
nomytics, 192
nomztics, 192
nonlinear, 29, 192
nonuniform, 246, 247
nooffsets, 196
noparametric, 203
nopolar, 210
norm, 39, 40
nosurface, 222
notimestamp, 225
nox2dtics, 231
nox2mtics, 231
nox2tics, 231
nox2zeroaxis, 231
noxdtics, 232
noxmtics, 233
noxtics, 235
noxzeroaxis, 240
noy2dtics, 240
noy2mtics, 240
noy2tics, 240
noy2zeroaxis, 240
noydtics, 240
noymtics, 241
noytics, 241noyzeroaxis, 241
nozdtics, 241
nozmtics, 242
noztics, 242

317

318
nozzeroaxis, 241
objects, 193
octal, 38
offset, 29
offsets, 151, 185, 196
okidata, 275
one’s complement, 49
operator precedence, 49
operators, 49
origin, 104, 190, 196
output, 197
overflow, 42, 197
palette, 26, 42, 57, 99, 144, 155, 159, 181, 198,
202, 205, 207, 208, 219, 220, 227, 243,
244
parallel, 89
parallelaxes, 89, 204, 221
parallelaxis, 204
parametric, 151, 203, 227, 229
path, 26, 129, 132
pause, 119
paxis, 89, 203, 221
pbm, 284
pcl5, 278, 284
pdf, 54
pdfcairo, 262, 280, 285
perpendicular, 124
persist, 63
pi, 52
pict2e, 281, 286
piechart, 77
piped data, 135
piped-data, 124
pipes, 135
pixels, 86, 302
pixmap, 204
placement, 175
plot, 120, 147, 245, 246, 251
plot styles, 71
plotting, 63
plugins, 63, 114, 117pm, 287
pm3d, 74, 77, 159, 205, 220png, 54, 280, 287
pngcairo, 288, 302
pointinterval, 88, 218
pointintervalbox, 210
pointnumber, 88, 218
points, 88, 90
pointsize, 144, 175, 210
pointtype, 90
polar, 63, 90, 210, 212, 213, 227

gnuplot 6.0
polygon, 195
polygons, 29, 91
pop, 223
position, 205
postscript, 54, 289, 291
practical guidelines, 109
precision, 42
print, 145
printerr, 145, 146
printing, 303, 304
projection, 229
prologue, 36, 272, 289, 292, 293
psdir, 212, 292
pseudo mousing, 120
pseudo-mousing, 28, 280
pseudocolumns, 130, 136, 137
pseudofiles, 134
pslatex, 263, 273, 281, 293
pstex, 293
pstricks, 281, 294
punctuation, 67
push, 223
pwd, 146
qt, 295
quit, 146
quotes, 23, 38, 68
raise, 118, 146, 308
rand, 40, 45
random, 45
range frame, 239
rangelimited, 239
ranges, 105, 139
ratio, 213
raxis, 212
real, 40
record, 55
rectangle, 194, 217
refresh, 135, 138, 146
regis, 296
remultiplot, 147, 191
replot, 135, 147
reread, 147
reset, 147, 149
restore, 233
return, 24, 148
RGB, 202
rgbalpha, 85
rgbcolor, 42, 58, 59
rgbformulae, 199
rgbimage, 85, 212
rgbmax, 212
Riemann, 49

INDEX

INDEX
rlabel, 212
rmargin, 212
rms, 209
rotate, 86, 124round, 42
rrange, 90, 152, 211–213
rtics, 212, 213, 227
sample, 140
samples, 131, 138, 173, 174, 213, 222, 227
sampling, 134, 139, 140, 213, 246
save, 148
sbezier, 133scan, 123scansautomatic, 208
scansbackward, 208
scansforward, 208
scope, 24, 56, 64, 114, 118
screen, 55
screendump, 304
scrolling, 188, 189sectors, 81, 93
seeking assistance, 23
separator, 126, 136, 162
sequences, 35, 54, 90
series, 236
session, 148set, 149
sgn, 40
sharpen, 130
shell, 243show, 149
sin, 40
sinh, 40
sixel, 54, 281
sixelgd, 101, 281, 296
size, 104, 190, 203, 213, 276, 279, 288
SJIS, 166sjis, 166skip, 126, 127, 131
slice, 26, 53
smooth, 131, 213
space, 61
sparse, 26, 81, 85, 247, 248
special filenames, 134
special functions, 25, 45
special linetypes, 29, 60
special-filenames, 55, 124, 227, 246
specifiers, 169, 186, 295
specify, 67
spiderplot, 29, 93, 138, 221
splines, 131split, 26, 48, 53, 65
splot, 147, 172, 230, 245

gnuplot 6.0
spotlight, 28, 207
sprintf, 41, 65, 180
sqrt, 40square, 90, 213, 214
starc, 275
start, 64
start up, 64
starting values, 111
startup, 36, 64
statistical overview, 109
statistics, 251
stats, 251
steps, 80, 94
strcol, 47
strftime, 41, 65, 170
string, 65
string operators, 49
stringcolumn, 47
strings, 65, 180
strlen, 41
strptime, 41, 65, 170, 239
strstrt, 41, 65
style, 136, 143, 181
styles, 120, 143, 214, 217, 218
subfigures, 63
substitution, 66, 68, 185
substr, 41, 65
substring, 41
substrings, 65
summation, 51, 56, 197
surface, 81, 99, 160, 222, 250
svg, 270, 297
svga, 298
SynchrotronF, 25, 45
syntax, 23, 67, 169, 227, 233
system, 41, 243, 253
table, 143, 222tan, 40
tandy 60dpi, 275
tanh, 40tc, 57
tek40, 298
tek410x, 298
term, 148, 257
terminal, 55, 257
terminals, 223
termoption, 224
ternary, 50
test, 26, 57, 144, 251, 253
texdraw, 281, 298
text, 68, 180, 261, 287, 298, 303
text markup, 34
text menu, 304

319

320
text-menu, 306
textbox, 180, 221
textcolor, 57
tgif, 299
theta, 90, 93, 211, 224
tics, 224
ticscale, 225
ticslevel, 225tikz, 300
time, 28, 45, 69, 170, 191, 225, 238
time specifiers, 29, 45, 69, 170, 226, 232, 239
time/date, 68, 226, 232
timecolumn, 46, 47, 225, 232
timefmt, 34, 45, 139, 170, 181, 225, 232
timestamp, 225
tips, 112
title, 34, 226
tkcanvas, 300
tm hour, 41
tm mday, 41
tm min, 41
tm mon, 41
tm sec, 41
tm wday, 41
tm week, 46, 47, 171
tm yday, 41
tm year, 41
tmargin, 227
toggle, 253
tpic, 29, 281
trange, 227
transparency, 86, 155transparent, 218
transpose, 123
trim, 41, 48, 65
ttics, 90, 227
uigamma, 24, 44, 47
unary, 49
undefine, 254
unicode, 35, 54
uniform, 246, 247
unique, 132, 133
unset, 254
unwrap, 133
update, 255
urange, 227
user defined, 52
user-defined, 138
using, 34, 37, 46, 47, 51, 71, 125, 135, 206, 251
UTF 8, 166, 292
utf8, 36, 66, 166v6 changes, 30

gnuplot 6.0

INDEX

valid, 47
value, 48, 52
variable, 72, 73, 75, 79, 87, 88, 90, 95, 130, 209variables, 48, 51, 52, 61, 62, 91, 119vclear, 255
vectors, 71, 95, 141version, 24
version 5, 29
vfill, 100, 250, 255
vgagl (linux console), 281
vgfill, 255
vgrid, 100, 228, 245, 250
view, 99, 228, 239, 245
viridis, 201
voigt, 40
volatile, 138
voxel, 42voxel grids, 250
voxel-grids, 228, 245
VoxelDistance, 255
VP, 25, 40, 45
VP fwhm, 25, 40, 45
vrange, 229
vttek, 298
vxrange, 229, 230, 245
vyrange, 230
vzrange, 230
walls, 230
warn, 256
watch, 69
watchpoints, 28, 69, 70
webp, 101, 302
weekdate cdc, 46, 47
weekdate iso, 46, 47
wgnuplot.ini, 305
wgnuplot.mnu, 305
while, 56, 104, 256
windows, 302
windrose, 93
with, 143, 210, 214
word, 41, 48, 65
words, 41, 48, 65
writeback, 233
wxt, 54, 306
X resources, 308, 310–312
X11, 307x11, 307
x11 fonts, 309
x2data, 231
x2dtics, 231
x2label, 231
x2mtics, 231

INDEXx2range, 231
x2tics, 231
x2zeroaxis, 231
xdata, 34, 181, 226, 231, 240, 241
xdtics, 231, 232, 240, 241
xerrorbars, 96
xerrorlines, 97
xfig, 275
xlabel, 212, 231, 232, 240–243
xlib, 312
xmtics, 231, 233, 240–243
xrange, 151, 204, 211, 231, 233, 240–243, 251
xterm, 298
xticlabels, 34, 138
xtics, 28, 153, 169, 172, 184, 192, 204, 213, 225,
227, 231, 235, 240–243
xyerrorbars, 96
xyerrorlines, 97
xyplane, 33, 225, 229, 239, 241, 245
xzeroaxis, 240
y2data, 240
y2dtics, 240
y2label, 240
y2mtics, 240
y2range, 240
y2tics, 240

gnuplot 6.0
y2zeroaxis, 240
yaft, 281
ydata, 240
ydtics, 240
yerrorbars, 97
yerrorlines, 98
ylabel, 241
ymtics, 241
yrange, 241
ytics, 241
yzeroaxis, 241
zclip, 77, 205
zdata, 241
zdtics, 241zero, 242
zeroaxis, 231, 239–242
zerrorfill, 29, 79, 100
zeta, 24, 49
zlabel, 242
zmtics, 242
zoom, 189
zrange, 242
zsort, 29, 130
ztics, 242
zzeroaxis, 241321