From: prom@gleep.world (Gary Promhouse)
Subject: Re: Gotta see those graphs
Organization: /u3/thesis/prom/.organization
Date: Wed, 7 Oct 1992 03:55:36 GMT
	<1992Oct6.174627.6118@cbfsb.cb.att.com>


Several public domain packages are available for analyzing and displaying data
supplied as text files. All the packages I will list are available for DOS,
UNIX and most other widespread operating systems. They are all easily
downloaded by anyone on the internet via anonymous ftp. The text files used by
these systems have the additional advantage that they could easily be posted
to this newsgroup for analysis by others.

- gnuplot is able to generate very good looking 2D and 3D plots from text
formated numeric data. It can create output in postscript, or LaTeX, or other
formats required by many plotters, printers and interactive display devices.
The command language for gnuplot is very easy to use and the system provides
good help. For example, one demo provided with the system produces a plot of
three different data sets on the same graph using the following :

plot [-19:19] '1.dat'with impulses ,'2.dat' ,'3.dat' with lines

The notation for adding titles, line labels, adjusting symbols, etc. are
equally transparent. After displaying data on a screen one could output it in
postscript with two simple commands. In additional, to being public domain,
and have ports for most systems, there is now a gnuplot newsgroup so help is
probably easy to obtain.

- a package called "xlisp-stat" provides a statistical analysis and data
visualization package which runs on most available GUIs (e.g. windows 3.1,
X11, Macintosh, amiga). The system is built on an object-oriented extension of
common lisp. The primitives it provides for analysis and visualization are
very powerful. For example various regresssion systems are supported, while
others can easily be constructed using its vectorized arithmetic ops. It
further provides primitives for easily adding or extending menus, dialog boxes
and other GUI components to customize the interface for specific applications.
There is a good reference book written by the creator which provides many
examples of how to use the system. Again it reads text input.

- a package called "statv53" provides an extensive set of statistical analysis
tools (such as linear and non-linear reqressions) given textual input data.
Although I am only aware of a DOS version of these tools, I suspect that it,
or something better is available for other systems. I am not sure if it is
public domain or not.

- awk or perl scripts can be easily created to
  - look for specific types of behavior in the data
  - extract specific fields and format the data as required by any of the
    other packages listed above
  - both packages have extensive documentation, perl has a newsgroup which is
    very responsive to queries

If desired I will summarize ftp sites where these packages may be obtained.

The following is a sample of the 2D data used by gnuplot or any of the other
systems mentioned above

#
# $Id: 1.dat,v 3.26 92/03/24 22:32:15 woo Exp Locker: woo $
#
-20.000000 -3.041676
-19.000000 -3.036427
-18.000000 -3.030596
-17.000000 -3.024081
-16.000000 -3.016755
-15.000000 -3.008456
-14.000000 -2.998978
-13.000000 -2.988049
-12.000000 -2.975310
-11.000000 -2.960273
-10.000000 -2.942255
-9.000000 -2.920278
-8.000000 -2.892883
-7.000000 -2.857799
-6.000000 -2.811295
-5.000000 -2.746802
-4.000000 -2.651635
-3.000000 -2.498092
-2.000000 -2.214297
-1.000000 -1.570796
0.000000 0.000000
1.000000 1.570796
2.000000 2.214297
3.000000 2.498092

Gary
Newsgroups: sci.physics.fusion