GeoVu

Data Access and Visualization Software

User's Guide![](media/image1.emf){width="1.0298611111111111in"
height="0.9395833333333333in"}

UNITED STATES DEPARTMENT OF COMMERCE\
National Oceanic and Atmospheric Administration\
National Environmental Satellite, Data, and Information Service\
National Geophysical Data Center\
Boulder, Colorado 80303 USA

## DISCLAIMER

While every effort has been made to ensure that the product is accurate
and reliable within the limits of the current state of the art, NOAA
cannot assume liability for any damages caused by inaccuracies in the
product or as a result of the failure of the product to function on a
particular system. NOAA makes no warranty, expressed or implied, nor
does the fact of distribution constitute such a warranty.

The user must be cautious when using this computer program and
associated data. As in any complex scientific effort, errors can be
expected.

## TRADEMARK ACKNOWLEDGMENTS

In this documentation for GeoVu, trademarked commercial products and
companies are named. Mention of a commercial company or product does not
imply endorsement by NOAA or the Department of Commerce. Use for
publicity or advertising purposes of information from this publication
concerning proprietary products or the tests of such products is not
authorized.

Throughout the publication, rather than put a trademark symbol in every
occurrence of a trademarked name, we state that we are using the names
only in an editorial fashion with no intention of infringement of the
trademark.

## CONVENTIONS

You will find the following typographic conventions throughout this
guide. The sections of this document which are marked by @ will also be
found in the HELP panels viewed while running GeoVu.

  ------------------- ---------------------------------------------------
  [Small              Dialog box titles you will see while running GeoVu.
  Caps]{.smallcaps}   

  **bold**            Boldface words represent titles, keywords, literal
                      strings, fixed file names, and menu item names.

  *italic*            Special terms used in this guide. Also place
                      holders for information you must provide.

  typewriter          Presentations of text file contents.
  ------------------- ---------------------------------------------------

# Table of Contents {#table-of-contents .header_part}

**Part One -- Getting Started**

Installing GeoVu

Starting GeoVu

\@Preparing Data For Use With GeoVu

Part Two -- Running GeoVu

\@Prepare the GeoVu Session

\@File Menu

Set Data Source

Close CD Data Source

Open Data

Close Data

Exit GeoVu

\@Edit Menu

Data Header

Data Formats (release 6 or later)

Image File Information\...

Data Source List

Preferences (release 6 or later)

\@Search Menu

Create

Revise

Delete

Display

\@GeoReference Menu (GeoRef)

Load GeoVu Rivers/Coasts

Load GeoVu Boundaries

Display GeoRef Overlay

\@Utilities Menu

Slide Show\...

Image Processes\...

View File Histograms

\@Windows Menu

Status

Close All Displays

(Window Titles)

\@Help Menu

Contents

About, On Version

\@Interactions with the Display Windows

\@Image Display Controls

\@GeoRef Overlay Display Controls

\@Plot Display Controls

\@GeoVu Accessory Files

\@GeoVu\'s help file

\@World Coastline, Bounds Files

\@Data Source list file

\@Menu (.men) Files

\@Format Specification (.afm, .bfm, .fmt) Files

\@Formats list file stdform.nam

\@Name Table / Equivalence Table (.eqv) Files

\@GeoVu\'s Palettes List File

#  Index of GeoVu Dialog Titles {#index-of-geovu-dialog-titles .header_part .unnumbered}

Change Dataset Display Attributes, 36

Data Source, 12

Data Source List Management, 19

Data Source Selections, 20

Data Type, 16

Facts (for Data Collection or CD-ROM Access), 15

File Header, 17

Format Type, 16

Histograms: data set title, 31

Image Information, 18

Image or Map Area Definition (for image data only), 22

Image Processing Utilities, 31

Image Search Parameters (for image data only), 21

Introduction (For Data Collection or CD Access), 13

Open Files List, 17

Open: Title (for Data Collection or CD-ROM Access), 14

Output File Information, 25

Plot Axes and Constraints (for point data only), 24

Plots:Title (for point data only), 23

Preview, 15

Processing Information, 26

Resource List, 17

Search Selection List, 26

Select Data File (For Disk File Access), 13

Select Slides: Title, 29

Slide Show, 30

Slide shows data type, 30

Specify Plot Display Attributes, 37

Variable List, 24

View (for Data Collection or CD-ROM Access), 15

# Part One -- Getting Started {#part-one-getting-started .header_part}

# Installing GeoVu

The GeoVu application is available on the following platforms:

-   Under Microsoft Windows, GeoVu operates on any IBM PC 386 or 486 or
    compatible personal computer. The minimum configuration is DOS 5.0
    running Microsoft Windows 3.1 in enhanced mode and having a
    Windows‑supported mouse device. A Windows-supported video system of
    VGA or better resolution is required, and optionally, a CD-ROM drive
    and standard CD-ROM file access software.

-   GeoVu is also available as a MOTIF 1.1 program running on SUN Sparc
    workstations and as a MOTIF 1.2 program running on SGI workstations.

-   A version for Apple Mac is also available. We suggest a 68020-based
    machine (Mac II or later) with a color monitor, 4 MB of RAM, and
    System 6 or later.

GeoVu Data Sampler is a data collection compiled for use with GeoVu
demonstrations and tutorials. GeoVu access software and the GeoVu Data
Sampler are available on diskettes or as files accessible via anonymous
ftp.

FTP Access: A computer connected to Internet and supporting the ftp
command can be used to download GeoVu files. Type **ftp
ftp.ngdc.noaa.gov**. Log in using anonymous for the name; use your own
e-mail address or local login name. GeoVu access software is found in
the directory **Solid_Earth/Access_Tools/GeoVu**; GeoVu Data Sampler is
found in the directory **Solid_Earth/Access_Tools/GeoVu/Sampler**. These
directories contain executable and binary files which must be downloaded
in binary mode. Be sure to look at the ASCII README files found there
for installation instructions.

GeoVu is available on-line from the World Wide Web:

**ftp:://ftp.ngdc.noaa.gov/Solid_Earth/Access_Tools/GeoVu**

To install GeoVu for PC from diskettes:

Insert the diskette into the appropriate disk drive.

Run the program SETUP found on the diskette. If Windows is running, use
the Program Manager File menu to select Run. If a: is the drive used,
type **a: setup** in the Run dialog. If Windows is not running, type
**win** to run Windows.

Follow the installation instructions on the screen. The contents of the
GeoVu distribution diskette are copied to your hard drive in the
directory of your choice.

To install GeoVu for Motif from our ftp file:

The file **geovu.tar.Z** is a compressed tar file containing the GeoVu
executable and associated files. Download this file in binary mode and
place it in the directory where you wish to install GeoVu (typically
your home directory).

Then enter the following commands:

**uncompress geovu.tar.Z**

**tar xvf geovu.tar**

This generates a **geovu/** directory and a simple file **g2**. This
**g2** file is an X applications defaults file to be put into your home
(**\~**) directory.

The **geovu** directory is what should be pointed to by the environment
variable GEOVUDIR. For example, if you use the C Shell, put the
following line in your **.cshrc**:

**setenv GEOVUDIR \~/geovu**

Of course, this assumed you un-tar\'d **geovu.tar** in your home
directory - though this is not necessary. The GeoVu executable is called
**g2**.

To install GeoVu for Macintosh from ftp downloaded file (also World Wide
Web):

In ASCII text mode, get the file **geovu.sea.hqx**. Depending on the
setup of your FTP or Web software, the entire decoding and installation
may take place automatically, installing the **geovu** folder onto your
hard disk. If only the **geovu.sea.hqx** file is installed, decode this
file with StuffIt Expander or BinHex. These are free software utilities
available in many places including:
**http://hyperarchive.lcs.mit.edu/HyperArchive.html**. Double-click the
**geovu.sea** icon to install the **geovu** folder anywhere you like on
your hard drive.

To install GeoVu for Macintosh off a PC CD-ROM:

Copy the file **geovu.sea.hqx** to your hard drive. Because the CD-ROM
was made on a DOS-based computer, this name is truncated to something
like **geovu_se.hqx** or **geovusea.hqx**. Decode this file with StuffIt
Expander or BinHex. These free software utilities available in many
places including: **http://hyperarchive.lcs.mit.edu/HyperArchive.html**.
Double-click the **geovu.sea** icon to install the **geovu** folder
anywhere you like on your hard drive. (This may have happened
automatically, depending on your StuffIt settings.)

You will have to convert the ASCII menu files to Macintosh end-of-lines
(EOLs) with a small utility we provide in the installation package. This
only works by Drag & Drop: drag the menu file (a file ending in
**.men**) onto the Make Mac EOL application and click the Mac (CR) radio
button.

**Questions?** Contact Allen Hittelman at NOAA\'s National Geophysical
Data Center:

Phone: 303-497-6591

Fax: 303-497-6513

Internet: amh@ngdc.noaa.gov.

# Starting GeoVu

To start GeoVu as a Windows desktop application, double-click on the
GeoVu icon.

To start GeoVu for Motif, enter the command **g2** from the Xterm window
prompt, if your current working directory is the GeoVu directory. To
start GeoVu as a desktop application, use your X window manager's icon
binding tool to set up the icon. Then click on the GeoVu icon.

To start GeoVu for Macintosh, double-click the GeoVu application icon
found in the GeoVu folder.

# \@Preparing Data For Use With GeoVu

In order to work with a data file, GeoVu needs to know information about
the data including format and type. The data file does not require
special formatting or reprocessing to be displayed in GeoVu, but the
appearance of the data must be described in accessory files that are
used by GeoVu as it runs. If these are not provided, it is possible that
GeoVu will be able to continue using the default information and
information that you type into dialogs during the session.

For data collections that reside on a CD-ROM, a menu (**.men**)
navigation file is written by the data provider. When this file is
provided, it specifies the data type, the format of the input data, and
other information. The *GeoVu Tools Reference Guide* details how to
customize GeoVu and how to link it to new data products. The most recent
**.men** files available for our data collections, including corrected
files, are also available from our ftp location.

# Part Two -- Running GeoVu {#part-two-running-geovu .header_part}

Pull-down menus are a familiar part of any windowing application. They
appear at the top of the application window and each displays a family
of commands when you click on it. The GeoVu menus are File, Edit,
Search, GeoReference, Utilities, Windows, and Help. (Older releases also
had the Documents menu.) Under Microsoft Windows, Help is also available
by pressing the function key F1. The Help Contents panels shown are the
same text that is Part Two of this document.

# \@Prepare the GeoVu Session

GeoVu uses its own general methods to find, search, store, and display
data. External descriptions of specific data, as files and as
collections, provide levels of compatibility with GeoVu\'s features and
operations. A fully GeoVu-compatible data collection is described by a
*menu file*. The menu file contains *keywords* used to customize access
to data, providing data-specific equivalents for GeoVu\'s own general
methods. Reasonable defaults for the keywords are in place so that many
data sets can be accessed without a menu file description. Some GeoVu
keywords are found as environment variables (Unix or Windows) or stored
in the application\'s Windows initialization file, **freeform.ini**, or
Macintosh preferences file, **GeoVu Prefs**.

In addition to the menu files, GeoVu reads FreeForm data description
files, files containing color palette definitions, and other accessory
files that determine the details of your GeoVu session. See "GeoVu
Accessory Files".

The first time your run GeoVu, or whenever you install compatible data
collections, or whenever you wish, you can reconfigure GeoVu to use
defaults for your session. Your first task should be to update GeoVu\'s
list of available data sources. This list of data sources is used
throughout a session in the user interface. It is written and maintained
by GeoVu in an editable text file called **cdm_serv.lst**, placed in the
GeoVu working directory. GeoVu manages this file automatically; you
select the **Edit** menu item **Data Source List\...** to create or
update the list to match your installation.

By editing the **cd_driver** line found in this file, you can also
customize the default data home directory (Windows and UNIX), drive
letter (Windows), CD-ROM device name (UNIX), or CD-ROM volume name
(MAC). Use the syntax and specification appropriate for each machine
type.

# \@File Menu

Select or release a data source, open or close a data file, or quit
GeoVu. This menu is used to select data sources as working data ready
for use during the session.

**Usually you will set a data source, open one or more data files, then
use the Search menu to prepare views of the data.**

## Set Data Source

A *Data Source* is a collection of data sets, found on a CD-ROM or on
hard disk. The **Set Data Source** menu item lists the available data
sources supported in your currently installed configuration. You may
select one as the source of working data. If you do not see expected
sources listed, use the **Edit** menu item **Data Source List\...** to
update GeoVu\'s source list file.

GeoVu can run with no source list file or with an empty list; the only
data source will be **Disk Files**. In this case, GeoVu skips the [Data
Source]{.smallcaps} dialog and directly presents you with the standard
Windows, Mac, or MOTIF [Open File]{.smallcaps} dialog.

![](media/image2.emf){width="4.25in" height="2.625in"}

### Data Source {#data-source .dialog_title}

Once you select the menu item **Set Data Source**, a list of available
data sources appears. The list always includes the choice **Disk Files**
for data which is not part of any collection accompanied by a GeoVu
*menu file*. Data file descriptions make it possible for GeoVu to access
data in files, but this is only the first level of compatibility with
GeoVu that is possible. Select **Disk Files** to open these data files
on disk. This choice disables the CD or Data Drive editing box and
presents you with the standard [Open File]{.smallcaps} dialog, titled
[Select Data File]{.smallcaps}.

At the next level of GeoVu compatibility, menu navigation through a
collection of datasets is provided by a *menu file*, insulating you from
directory paths and file names. Select the name in the list to use one
of these collections or CD-ROM products. If the name you want is
missing, you need to customize your installation or find a missing
**.men** file. Place menu files in the GEOVUDIR location. See **Edit**
menu item **Data Sources\...**

If you select one of the CD-ROM volumes or data collections, you may
need to change the drive letter in the CD or Home editing box (for PC,
e.g., **S:**)(for Unix, e.g., **/cdrom1**). If the CD volume found in
the drive is not the one selected, you are prompted to insert the
correct CD. If the data collection selected is not found on the drive,
you will see a warning message. On the Macintosh, the name of the CD or
the hard disk location where the data is located must be correctly typed
(though not case sensitive) into the editing box. This is different for
every CD you insert and is the drive name that appears on the Mac
desktop.

### Introduction (For Data Collection or CD Access) {#introduction-for-data-collection-or-cd-access .dialog_title}

When you select a data source by title, you will see an INTRODUCTION
screen, which gives some information about the CD or data collection.
Continue by using the OK button to return to the main GeoVu menu, or
click the Open Data\... button to go immediately to the [Open
Data]{.smallcaps} dialog.

## Close CD Data Source

When many sources are open, Close CD Data Source is used to unload the
GeoVu links to the CD, removing the menu navigation system for that CD.
This clean-up makes room for new sources to be set. To use the same
CD-ROM drive but a new CD in it, also close the previous CD's open
files.

## Open Data

The menu item **Open Data** becomes available only after a data source
has been selected using **Set Data Source**. After opening a file, you
can retrieve data and view them using the **Search** menu.

Note that there is a limit to the number of files that can be open at
once. This limit may be 13 or 14 files under Windows, and it is possible
that GeoVu will be able to open a data file but unable to open the
header file or some other associated file. GeoVu is not able to check
for all possible combinations, which may lead to unexpected results. It
is best to close files that are no longer of interest.

### Select Data File (For Disk File Access) {#select-data-file-for-disk-file-access .dialog_title}

A standard Windows, Macintosh, or MOTIF [Open File]{.smallcaps} dialog
appears if the data source is **Disk Files**.

### Open: Title (for Data Collection or CD-ROM Access) {#open-title-for-data-collection-or-cd-rom-access .dialog_title}

![](media/image3.emf){width="5.358333333333333in"
height="3.3916666666666666in"}

If the data source selected for **Open Data** is a CD or special data
collection, GeoVu provides hierarchical menu navigation. A dialog is
displayed with the source title as the window\'s title. It guides you
through selecting subsets of data from title lists. This menu guide
provides a mechanism for finding the data you want without knowledge of
the specific directory structure or file names used on the CD or disk.

Facts: Display information about the highlighted item in a text dialog.

View: Display the selected ASCII data or text file. This button is
disabled if not applicable.

\<\<Prev: Return to previous group if there is one or return to the
Introduction.

Next\>\>: Display the names of the next group.

OK: Select the highlighted item. Double-clicking the item also selects
it. If the selected item is a data set, it is opened by GeoVu.

CANCEL: Close the dialog without making a selection.

### Facts (for Data Collection or CD-ROM Access) {#facts-for-data-collection-or-cd-rom-access .dialog_title}

\<\<Prev: Display information for the previous item in the menu list.

Next\>\>: Display information for the next item in the menu list.

CANCEL : Close the [Facts]{.smallcaps} window and return to the menu
guide.

### View (for Data Collection or CD-ROM Access) {#view-for-data-collection-or-cd-rom-access .dialog_title}

This display is possible only when a text file has been selected from
the lists. The file may be a description file or ASCII data.

\<\<Prev: Display information for the previous item in the menu list.

Next\>\>: Display information for the next item in the menu list.

CANCEL : Close the [Data]{.smallcaps} window and return to the menu
guide.

Using the dialogs discussed above, a specific data set has been selected
for use. Before GeoVu proceeds, it checks for a special preview
capability. If a summary image of the data has been provided and the
GeoVu keyword **preview** has defined to be Yes, the preview image is
displayed. You can continue on to create searches of the actual data
after dismissing the preview. Preview data corresponding to large data
sets are useful as summary information, providing an overview before
time is spent retrieving unconstrained data.

### Preview {#preview .dialog_title}

**Preview shown. Do you want this data set?**

No: Delete the preview image and close the preview data. GeoVu returns
to the menu guide.

Open+Disp: Open the selected data set and display it using default
settings. This search retrieves all data.

Open Only: Open the selected data set. You will need to define the
search using the **Search** menu item **Create**.

### Format Type {#format-type .dialog_title}

GeoVu attempts to determine the format of the data sets before they are
opened. If it fails to find the information, the Format Type Dialog
appears. This dialog lists available common formats plus an UNKNOWN
option. If the data file is in a non-standard format, select UNKNOWN,
which allows you to continue and enter the necessary information.

See the **GeoVu Accessory Files** for information about the standard
formats list file **stdform.nam**.

### Data Type {#data-type .dialog_title}

If GeoVu cannot determine the data type of the input file, this dialog
appears. Select one of the three types of data known to GeoVu: Image or
Raster, Vector, and Point. In the current GeoVu release, vector data
capabilities are not complete.

As GeoVu prepares to open an image data file, the attributes of the
image are found. These include: image name, number of rows, number of
columns, number of bands, data type, number of bytes per pixel, format,
projection, pixel size, and map coordinates of the image boundary. If
essential information is not found, the attributes of the image are
displayed automatically using the **Image Information** dialog discussed
below, as you can also access it from the **Edit** menu. You must type
in the missing information. Changes made affect future searches and
displays of the image data, but do not the revise the current displays.
Also, these changes will be lost when the GeoVu session ends.

## Close Data

Closes an open data file and cleans up GeoVu references to it. **Close
Data** does not close the graphical display windows for the data. This
item is disabled when there are no open files.

Note that there is a limit to the number of files that can be open at
once. This limit may be 13 or 14 files under Windows, and it is possible
that GeoVu will be able to open a data file but unable to open the
header file or some other associated file. GeoVu is not able to check
for all possible combinations, which may lead to unexpected results. It
is best to close files that are no longer of interest.

### Open Files List {#open-files-list .dialog_title}

Select one or more file to close from the list of open files.

## Exit GeoVu

Exit GeoVu − no dialogs are presented.

# \@Edit Menu

## Data Header

This menu item allows you to view and modify (edit) items found in a
data file header of an open data source.

### Resource List {#resource-list .dialog_title}

If more than one file is opened, select one from the list that appears.

### File Header {#file-header .dialog_title}

This dialog displays the items from the header and their current values.
Any of the values can be modified by typing over the values.

PG UP: Display the previous 10 items.

PG DOWN: The dialog displays 10 items at once. If the header contains
more than 10 items, click this button to display the next 10 items.

OK: Save the changes to the header and quit the **File Header** dialog.
If the data set is an image, the modified Image Information dialog is
displayed.

CANCEL: Quit without saving the changes.

## Data Formats (release 6 or later)

This menu item allows you to view and modify (edit) items found in a
format description for an open data source.

## Image File Information\...

### Image Information {#image-information .dialog_title}

You may check and correct each item. Information that is unknown is
shown with the special value -9999. Often you will see this value for
the number of rows and columns. Select MODIFY and enter the correct
numbers. Also GeoVu may make assumptions about the header or the
existence of an embedded header. If these defaults are not correct, you
may wish to set the header length to 0 or to the correct value. The
information shown in this dialog may indicate that GeoVu is not finding
format or other files you need to automate correct access to your data.
Select the LIST buttons to display a list of choices for each attribute.

The Image Information dialog appears automatically when needed but you
can also access it using the **Edit** menu item **Image File
Information\...** This lets you review and change image information for
subsequent image file access.

MODIFY: Allow the fields to be edited for corrections. If some changes
are made in the edit boxes, clicking this button again will reset the
boxes back to current values. Note the warning message! Select the LIST
option to present a list of choices for each attribute.

OK: Accept the modifications as shown and use it to open and read the
data. This button is disabled if there are no changes and the dialog is
for information only.

CANCEL: Dismiss the dialog, without making any changes.

## Data Source List

In addition to disk file access, GeoVu depends on a list of available
special data collections, each of which is fully GeoVu-compatible and
described by a GeoVu menu file. This list of data sources is used
throughout a session in the user interface, but it may need to be
customized or updated when you first install GeoVu or new compatible
data products.

The purpose of this menu item is to update and maintain the data source
list. The newly updated list is immediately available for the GeoVu
session in progress.

### Data Source List Management {#data-source-list-management .dialog_title}

GeoVu searches for possible data collections by finding menu files in
the GeoVu working directory. Note that these files end with a **.men**
extension, on all platforms. These possible data sources are compared to
the current data sources list available to GeoVu. The result is shown in
this dialog in two lists, those sources found on the list and those
found in the directory but not on the list.

The name used on the lists is determined by the file name or a title
name provided inside the file. If a title name is given in the menu file
under the section called **CD_MENU_NAME**, GeoVu uses this name on the
lists. If the **CD_MENU_NAME** section was not included, GeoVu uses only
the base file name.

The GeoVu Directory is given. (If this path is not what you expect, you
may need to correct the setting of the GEOVUDIR symbol.) This is where
the **.men** files must reside. Older versions of GeoVu allowed menu
files to be placed in other directories and this dialog had a Change
Directory feature.

The Title edit box allows you to change the logical name of a data
source. This is the name used in the [Set Data Source]{.smallcaps}
dialog. When you select an item from NOT [on Data Source
list]{.smallcaps}, its name appears in this edit box and the
[ADD]{.smallcaps} button becomes available. You must edit the name in
the edit box before pressing the [ADD]{.smallcaps} button. The new
source is added with the logical name as it appears in the edit box.

DELETE: Remove the item selected in [Sources on list]{.smallcaps} from
the sources list. NOTE: If an item was once set as a Data Source during
your GeoVu session, you will not be able to delete it here.

AddALL: Add all items listed in [Sources not on list]{.smallcaps} to the
sources list.

ADD: Add the item selected in [Sources not on list]{.smallcaps} to the
sources list.

OK: Save the contents of [Sources on list]{.smallcaps} to be the sources
list and make this list immediately available for access.

CANCEL: Close the dialog, making no changes to the data sources list.

## Preferences (release 6 or later)

Your GeoVu session can be controlled by a few settings found in the
Preferences dialog. Note the GeoVu Directory is shown to you here. This
dialog will also show you the values found for GeoVu keywords associated
with an open data set. If no data set is yet opened for use, the View
Data Keywords button will be disabled. This dialog is under construction
in Release 6 of GeoVu.

# \@Search Menu

A Search defines the retrieval and display properties of a data set.
Those include geographic bounds, scaling method, display type, palette
name, etc. This menu allows you to create, revise, or delete a Search
definition, and to display the data according to the criteria of the
Search.

## Create

To access and display an open data set, you must first create a Search.
Each data type (vector, point, raster / image) requires different
dialogs to completely specify the criteria of the data search, data
processing, and the resulting product.

### Data Source Selections {#data-source-selections .dialog_title}

If more than one data set is open, this selector appears when Create is
selected. The data set opened most recently is at the bottom of the
list. You must chose one set to be the current working set.

![](media/image4.emf){width="4.941666666666666in"
height="4.166666666666667in"}

### Image Search Parameters (for image data only) {#image-search-parameters-for-image-data-only .dialog_title}

This dialog allows you to set the criteria of the search. The initial
values shown are the defaults which are set automatically. If this
dialog is activated by the menu item **Revise**, the current parameter
values are displayed. You can change any of these parameters.

Search Name: The title which will appear on the display windows and in
selection lists. The default is the same as the data source name.

Palette Name: This list gives the palettes currently supported by GeoVu.
Select the one which is most suitable for your data.

Scaling Type: Select a data scaling method for image data. The GeoVu
default is to use 16 colors, so data must be scaled to 0-15.

-   Linear scaling bins the data evenly by 16 equal intervals between
    the data minimum and maximum.

-   In the current version of GeoVu, Frequency is never available.

-   The Linear about 0 selection will divide the data into two sets of
    bins scaled above and below the value 0. This is useful for displays
    of elevations above and below sea-level and topography of coasts.

-   Histogram equalization (Histo-Equalized) scales the image data so
    that each bin contains roughly the same number of pixels.

View Type:

-   Image or Map will result in an image display.

-   Table presentations are not yet implemented.

-   Save Search Definition Only will save the current Search by name
    without creating a display or file.

-   Select the option Write To Disk File to create a new file on your
    hard disk containing the data found when searched according to the
    criteria.

Set Search Parameter Limits: This button will call the appropriate
dialogs used to define the area of data to be displayed.

OK: Accept the names, types, and search limits defined and produce the
View Type.

CANCEL: Quit the dialog without saving the current Search definition.

### Image or Map Area Definition (for image data only) {#image-or-map-area-definition-for-image-data-only .dialog_title}

This dialog appears when you choose the Set Search Parameter Limits
button in Image Search Parameters and is used to set the area to be
displayed or retrieved.

Coordinate System: Allows you to select either **map** or **image** as
the coordinate system type used for the display area. If the image is
not georeferenced, GeoVu will disable the **map** option.

Start Column No (for image coordinates only) / Left LONG (for a Lat/Long
projection only) / Left Map X (for other map projections) This slide bar
allows you to set the horizontal coordinate of the left side of the
display area.

End Column No / Right LONG / Right Map X Allows you to set the
horizontal coordinate of the right side of the displayed area.

Start Row No / Top LAT / Top Map Y Allows you to set the vertical
coordinate of the upper side of the display area.

End Row No / Bottom LAT / Bottom Map Y Allows you to set the vertical
coordinate of the lower side of the displayed area. rich

Band to display: This slide bar is used to specify which band is to be
displayed when the data file contains more than one band.

Reduction Scale: This editing box is used to set the reduction scale of
display data. The default value is \[(number of
pixel-1)/(2048\*2048)\]+1, since 4,194,304 = 2048\*2048 is the largest
image size GeoVu currently allows.

Display Direction: Sets the row and column sequencing of the display
image. You can change the direction by selecting the LIST button to view
a list of directions: Normal, Inverse Column, Inverse Row, Inverse Row
and Column

OK: Quit this dialog saving the changes made and go back to the Image
Search Parameters dialog.

CANCEL: Quit this dialog without saving changes and go back to the Image
Search Parameters dialog.

### Plots:Title (for point data only) {#plotstitle-for-point-data-only .dialog_title}

Search Title: the title default will be the name of the data source.
Edit this title to save search definitions with unique names for use
again later.

Terms: any information available about the data variables selected below
will be displayed.

X variable names list: use this drop-down list to select a variable name
from those available.

Y variable names list: use this drop-down list to select a variable name
from those available.

Set Output/View Type:

> Simple XY-Plots places the results of the search in an XY-Plot.
>
> Multiple XY-Plots an XY-Plot of several Y variables (Implemented only
> in Release 6 or later.)
>
> Save Search Only keeps a definition for the search criteria by name.
>
> Write To File places the results of the search into a disk file.
>
> Show Values Table has not yet been implemented.

Set Constraints allows you to set one or two additional variable
constraints and to limit the X and Y variable range.

GO! is enabled when GeoVu has complete Search criteria and is ready to
produce the plot / search / file / table requested.

Get More Points will be enabled when GeoVu has searched data retrieving
the maximum number of points allowed. More points, up to the maximum
number again, can be retrieved using the same search.

### Plot Axes and Constraints (for point data only) {#plot-axes-and-constraints-for-point-data-only .dialog_title}

Set Constraints above will call up this dialog, used to specify one or
two constraints on the data to be displayed. You can define a range for
each variable by entering a minimum and a maximum limit. No limits are
imposed if both are set to 0. GeoVu will search for data records in
which the first constraint variable, the second constraint variable, the
X variable, and the Y variable are all within their limits and will plot
the values of X and Y variables as a coordinate pair.

X axis: set the range for the horizontal axis of the plot.

Y axis: set the range for the vertical axis of the plot.

First: set the first constraint variable name and set its range.

Second: set the second constraint variable name and set its range.

Example: A plot of temperature vs. precipitation may be constrained by
limits placed on the LAT and LONG variables associated with the data
records, restricting geographical area.

GeoVu finds variable names in the data format information and makes a
list of them. It tries to use X, Y, LAT, LONG, or the first names it
finds on the list as the default names to use in this dialog.

### Variable List {#variable-list .dialog_title}

Variables may also be set by clicking the associated LIST button to get
to the Variable List dialog. All available variables are listed by name
for you to select by double-clicking the variable name or by selecting
OK.

OK: Quit the dialog and replace the variable with the one highlighted in
the list box.

CANCEL: Quit without changes.

Terms: An explanation of the highlighted variable is presented if a text
file was provided for use with this feature. See "GeoVu Accessory Files"
and **GeoVu Keywords**, **term_definition**.

### Output File Information {#output-file-information .dialog_title}

If the view type in the Image or Plots dialogs is set to be Write To
Disk File, use this dialog to provide information that is needed to
write a new disk file.

File Name: Specify the output file name. The default file name is shown.
This file, without a full directory path, will be created on the current
default directory. You can change the file name or add a complete
directory path and name.

Data Type: Select the type of file, binary or ASCII, to be written. The
default type is the same as the input file. The default file extension
used for binary data is **.bin**; for ASCII data it is **.dat**.

Header Type:

None No data header will be created. The metadata is lost, so the output
file will be not readable by GeoVu.

GeoVu A header defined by GeoVu will be created in a separate file. The
default file extension used for the header file is **.hdr**. The output
data file will be readable by GeoVu.

Native A header will be created using the header format of the input
dataset. Information needed for GeoVu compatibility and which cannot be
written into the native header will be placed in an equivalence file,
having the file extension **.eqv**.

Output Lat/Long/Value File launches the program **grid2xyz**. This
program is only available for Windows.

OK: Accept the choices and begin the data processing.

Cancel: Quit without processing the data.

### Processing Information {#processing-information .dialog_title}

The Processing dialog appears while you wait for the resulting display
(or file-writing) and shows the progress. No response is needed, but a
CANCEL button is provided if you wish to interrupt the processing.

If an XY Plot is being displayed, you will see a note in the Processing
dialog reminding you of the maximum number of points GeoVu will plot.
Before the processing finishes, you will be presented with the dialogs
below to use to set plotting attributes such as marker types and colors.

## Revise

Change properties of an existing Search. The dialogs that are
encountered for the **Revise** menu item are the same as presented for
**Create**; please see **Create** above.

Be sure to give the new Search a unique name and delete the original
Search if you wish.

## Delete

Remove a Search that will not be used again.

### Search Selection List {#search-selection-list .dialog_title}

If more than one Search has been specified, this dialog presents a list
of available searches. Choose by name from the list presented. Your
choice will be deleted.

## Display

Display the results of a Search. You may not get what you expect if one
Search exists, another data file has just been opened, and you select
**Display** form the **Search** menu. If no Search definition has been
created for the new data set, you get a display of the Search that
already exists.

### Search Selection List {#search-selection-list-1 .dialog_title}

If more than one Search has been specified, this dialog presents a list
of available searches. Choose by name from the list presented. Your
choice will be displayed.

# \@GeoReference Menu (GeoRef)

This menu allows a fixed-format (free-format still in progress)
coastline file and a geopolitical bounds file to be read into the
session. It is intended that these files will be used as vector overlays
on map images.

This collection is available as an overlay to a map image display using
the OVERLAY control button found on image display windows. Non-linear
projections are not yet supported. The underlying image must be of
georeferenced data (having lat/long bounds). Georeferenced point
overlays for map images must first be created using the point data
plotting feature of GeoVu. Then these will be available using the
OVERLAY button.

The image information dialog will show you that the projection is
specified as Lat/Lon or you can use the **Edit** menu item **Image
Information\...** and click the MODIFY button to set this. Also the four
range values must be set so that the image is registered within GeoVu\'s
own map coordinates. GeoVu uses an internal coordinate system for these
overlay files of -180 to 180 and 90 to -90. Only contiguous ranges
within this system are used by GeoVu, although it will reset coordinates
that are specified with a longitude range within 0 to 360.

The two files used in GeoVu to provide coasts and boundaries are derived
from portions of Micro World Databank II.

Pospeschil, Fred 1992. Micro World Databank II

Coastlines, Country Boundaries, Islands, Lakes and Rivers. Digital
vector data at 1 minute resolution. In: Global Ecosystems Database
Version 1.0: Disc A. Boulder, CO: NOAA National Geophysical Data Center.
6 independent single-attribute spatial layers on CD-ROM, 2.5 MB.

## Load GeoVu Rivers/Coasts

Select **Load GeoVu Rivers/Coasts** to open the file of lat/long
coordinates to be used and displayed as coastal boundary lines. GeoVu
provides one world coastline data file, called COAST.DAT. If the file
COAST.DAT is not found in the working directory, you will be prompted
for the file name and directory with the standard open file dialog.

The binary file is in the format: one 4-byte LONG value specifying the
number of pairs to follow, followed by sequential pairs of LONG
coordinates (representing lat/long).This repeats for connected line
segments until the end of the file. No area searches can be done on
these files. GeoVu uses an internal geo-referencing system that expects
a resolution multiplier value of 1000 has been applied to the range of
-180 to 180 and 90 to -90.

## Load GeoVu Boundaries

Select **Load GeoVu Boundaries** to open the file of lat/long
coordinates to be used and displayed as country/state boundary lines.
GeoVu provides one world boundaries data file, called BOUNDS.DAT. If the
file BOUNDS.DAT is not found in the working directory, you will be
prompted for the file name and directory with the standard open file
dialog. This binary file has the format described above for the
coastlines data.

## Display GeoRef Overlay

The collection of overlay elements may also be displayed without an
image under it. To create this type of display, select the menu item
**Display GeoRef Overlay**. The controls available on this display are
discussed in the section **GeoRef Overlay Display Controls.**

# \@Utilities Menu

## Slide Show\...

This menu item allows you to sequentially display data sets from a
fully-compatible data source. This menu item is available only when a
menu file is provided that contains a section called **SLIDE SHOW** and
that section contains the word TRUE. The description of the data
collection includes this keyword to notify GeoVu that animations of
image displays would be appropriate.

![](media/image5.emf){width="5.358333333333333in" height="2.875in"}

### Select Slides: Title {#select-slides-title .dialog_title}

This dialog is similar to the dialog presented by the **Open Data** menu
item and is used to select files for display.

The Data Source box lists all items at the current level of the data
menu. To select an item for the slide show, double-click the item. A
**\*** before the name of a menu item indicates that item has been
selected. Double-click a selected item again to unselect the item and
remove the mark. Once an item has been selected, all files under this in
the menu hierarchy are selected with it. If this item is an individual
file, it is at bottom level of the data source menu and no other files
are selected. To select every data set available in the source, just
select all items in the top-level menu.

Facts: Display information about the highlighted item in the list box.

Select All: Select every item in the list box.

\<\<Prev: Go back to the parent level menu of the current menu.

Next\>\>: Go to the submenu highlighted in the list box.

OK: Available only after items are selected. Click this button to start
the show.

In some data collections, a prepared image file may be available,
corresponding to a data file. The data producer can write the data
collection\'s GeoVu menu file to allow the display of prepared images
for, giving the extension of the image file type. For example, there may
be a PCX file accompanying each real image data set. Keyword
**slide_show_ext** should be defined as PCX in the menu file (in the
default equivalence table). This notifies GeoVu that there are .PCX data
files as well as original real data sets that can be used for slide
shows. The following dialog will only appear if the keyword
**slide_show_ext** was found in a menu file.

### Slide shows data type {#slide-shows-data-type .dialog_title}

After selecting slides, you may be asked to specify the type of data to
show. The two choices will be [Real Data]{.smallcaps} or another type
which is specified. Use of the real image data file could be slow!
Choosing the prepared corresponding image of the data may be faster.

### Slide Show {#slide-show .dialog_title}

This dialog controls the slide show. You can move this dialog window to
any location, for a better look at the slide show session. The data file
name shown is the current file being prepared and the percentage of the
file that has been read is shown.

Step/Continuous: This button names two modes of presentation. If the
current name is Step, click this button to change the mode to
Continuous. Step mode will wait for you to click the Show Next button
before presenting the next slide. Continuous mode will display the next
slide immediately when it is ready. In GeoVu releases since 3.01, this
button is replaced by a pair of radio buttons.

Show Next: Display the next slide. Available only for the Step mode.

Cancel: GeoVu will ask you whether or not to abort the slide show. If
the answer is yes, GeoVu will stop the slide show, otherwise, it will
return to the slide show.

## Image Processes\...

The **Image Processes** menu item will present the following dialog only
if some image display window is selected as the active window.

### Image Processing Utilities {#image-processing-utilities .dialog_title}

This allows an image display currently in a selected window to be
re-computed into a new image which is smaller or is enlarged. That image
will be displayed in a new display window. Note that the new image is
not associated with the working data set that generates the original.

## View File Histograms

Histogram information may be available as metadata to be displayed and
examined. The histogram plots show the occurrences counted for values of
a variable. This feature is for browsing pre-computed histogram
information and does no data processing or computations.

For processing histograms of displayed images (pixel color frequency),
click the HIST button found on the image display control panel.

### Histograms: data set title {#histograms-data-set-title .dialog_title}

Each Histograms dialog works with only one open data set. To view
histograms for another open data set, close this window and return to
the Histograms menu item.

Variable: Select from the list of variable choices.

XYPlots: In the GeoVu current release, only XYPlots are shown. Later,
the option of table displays will be added.

Terms: Definitions or other information about the highlighted variable
will be shown if text has been provided for this.

# \@Windows Menu

## Status

Select this menu item to bring the status window to the front, listing
open data files and searches created.

## Close All Displays

This menu item removes all the display windows, but does not close files
or delete searches.

## (Window Titles)

The other Window menu items are titles of all the GeoVu display windows
and the always-present status window. Selecting one of these titles will
bring the window to the front.

# \@Help Menu

On a Macintosh running System 7.5 or later, this menu is under the ?
Apple Guide icon on the right side of the menu bar.

## Contents

This selection allows you to browse the contents of the GeoVu help text,
which is the same as Part Two of this User\'s Guide. This same help text
is available under Microsoft Windows by striking the F1 function key.
Note that if the GeoVu help file was not found when the session started,
there will be no response when Contents is selected.

## About, On Version

This selection presents information about the GeoVu release, version
number, and shows the support contact and a button for HELP Contents
display. Motif releases call this item On Version.

# \@Interactions with the Display Windows

GeoVu Display Windows present graphics for images, plots, georeferenced
points and vectors. Each has a set of button controls and customary
decorations used by Windows, Macintosh, or MOTIF applications.

Under Windows, an enlarge box and a close box (and its menu) are
available at the top of each window. MOTIF windows do not have the
enlarge box. To resize a window, click and hold on the window\'s frame
and drag the frame in the desired direction. Double mouse-clicks within
the title bar area will enlarge and restore window size. This will also
refresh the window with an updated display. If you hold the left mouse
button down and drag the title bar, the window will follow the mouse
movement if it is moveable.

When an entire display is not shown in the display window\'s drawing
area, active scroll bars will appear to provide panning of the display.
Under Windows, inactive scroll bars are removed but under MOTIF and
Macintosh they remain visible.

See the following sections: Image Display Controls, Georeferenced
Overlay Display Controls, and Plot Display Controls.

# \@Image Display Controls

The display of raster data is presented in an image display window,
titled with the data search name. These image display features and
controls are available:

\> A status bar along the bottom display area is used to show results
and prompts about cursor interactions. In the current release, the
cursor query interactions only provide screen and image information.

\> A color swatch legend shows the current color palette.

\> Cursor interactions with the window: Double-mouse clicks over the
image will select a point and present its row and column, color index,
and other information.

\> The OVERLAY dialog will be presented only when the image is
georeferenced; then it toggles drawing flags and colors for
georeferenced vector and point data sets, including a world grid and
elements added to the session using the GeoReference Menu.

\> COLOR control dialog will present a palette name list for selecting a
replacement color palette and will show the current colors and data
ranges. OKAY will update the image display to show the changes. CANCEL
will quit the dialog without changes to the image display.

\> ZOOMIN allows a region to be selected by a cursor-controlled rubber
band box. You can repeat this until precision fails or the image stretch
distorts too much.

\> ZOOMOUT will undo the last ZOOMIN.

\> SAVE the window\'s image only to a PC PCX file (run-length encoded or
not) or a PC DIB file (this is a **.bmp**), or a GIF file (Motif only),
or a PICT file (Macintosh only). You will be prompted for a name for the
output file.

![](media/image6.emf){width="5.358333333333333in" height="2.225in"}

\> PROFILE lets you enter a transect line across the image, then it
creates and displays an XY-Plot defined from the color indices along
that line. If the shift key is held down, you can select a series of
connected points to make the transect path. Release the shift key to
enter the final endpoint.

\> REGION allows an area selection by clicking and dragging the mouse.
You must enter a name tag for this region and it is then saved
throughout the session for use in named retrievals, but this feature is
still under development in releases earlier than 6.0.

\> FACTS will present any text information provided about the data that
is being used for the display.

\> HIST (histogram) will create a plot definition from values ranging
between 0.0 and 1.0 that describe the color frequencies of the image.
This plot is presented in a new XY-Plot Display Window.

# \@GeoRef Overlay Display Controls

This type of display presents georeferenced vector and point data
without an underlying map image. This is the type of display window that
appears when the menu item Display GeoRef Overlay is selected from the
GeoRef menu. These Overlay Display controls and features are available:

\> A status bar along the bottom display area is used to show results
and prompts about cursor interactions. Double-mouse clicks within the
display show GeoVu vector map coordinates here.

\> OVERLAY dialog toggles drawing flags and colors for session\'s
georeferenced vector and point sets.

\> ZOOMIN allows a region to be selected by a cursor-controlled rubber
band box. You can repeat this until precision fails or the image stretch
distorts too much.

\> ZOOMOUT will undo the last ZOOMIN.

\> REGION allows an area selection by clicking and dragging the mouse.
You must enter a name tag for this region and it is then saved
throughout the session for use in named retrievals, but this feature is
still under development in releases earlier than 6.0.

Scrolling through the display of a line drawing is very slow, so you
will not see the coastline or boundaries during the scrolling. When you
are done scrolling you can recover the line drawing part of your display
by forcing the screen to be redrawn. One way this can be done under
Windows is by clicking on the title bar.

# \@Plot Display Controls

This type of display is a 2D data plot, also called an XY-Plot. Also see
the discussion of **Search** dialogs. These Plot Display control
features are available:

\> OVERLAY toggle the grids and labels on a plot.

\> LEGEND control dialog presents the name of each data set and allows
changes to the display attributes of it: new line types or symbols may
be specified or the data will be \"undrawn\" by using the CHANGE button
and Change Dataset Display Attributes dialog.

### Change Dataset Display Attributes {#change-dataset-display-attributes .dialog_title}

A drawing method is specified by using the radio buttons and setting the
corresponding attributes. Also a color for gridding may be chosen.

CANCEL: Stop the plotting process.

UNDRAW: Removes the plot.

OK: Accept the settings made and continue.

\> ZOOMIN allows a region to be selected by a cursor-controlled rubber
band box. You can repeat this until precision fails or the image
distorts too much.

\> ZOOMOUT will undo the last ZOOMIN.

\> SAVE creates a .bmp file (or PICT file on Macintosh) from the screen
image created for this plot. A standard Save File dialog will request
that you enter the file name.

\> DATAOUT creates a file from the data created for this plot. A
standard Save File dialog will request that you enter the file name.

\> REGION allows an area selection by clicking and dragging the mouse.
The results are passed back to the application. Saving the regions is
not yet completed in GeoVu.

\> FACTS will present any text information provided about the data that
is being used for the display.

\> CUSTOM will allow you to customize the appearance of the plot. Future
enhancements are planned.

### Specify Plot Display Attributes {#specify-plot-display-attributes .dialog_title}

A linear or log scale may be requested. Labels may be changed here. Also
a background color may be chosen.

# \@GeoVu Accessory Files

The files below are provided with GeoVu or generated by it. Most are not
required, especially when Disk Files are the only data sources and not
CDs. All of these files may not have been installed with GeoVu.

## \@GeoVu\'s help file

This file (**g2.hlp** or **g2\_.hlp**) provides the text of the
instructions and the help panels−it is not otherwise readable. If it
does not reside in the GeoVu working directory, then GeoVu will prompt
for the filename. GeoVu can be run without this file but no HELP text
will be displayed.

To have written documentation for GeoVu (User's Guide and Tools
Reference Guide), send the **gv\*.ps** files found in the GeoVu
installation directory to a PostScript printer.

## \@World Coastline, Bounds Files

GeoVu uses only two binary georeferenced vector files, derived from
Micro World Data Bank II data files. The world coastline file is
COAST.DAT and the geopolitical boundaries are in BOUNDS.DAT. These have
a fixed format used directly by GeoVu displays. (The values are scaled
by a resolution factor and are represented as longs. The files are
sequences of the number of points in one continuous segment, followed by
the point pairs of that segment.)

## \@Data Source list file

GeoVu is compatible with many CD-ROM discs and special data collections,
such as the GeoVu Data Sampler. The ASCII file **cdm_serv.lst** contains
a default drive letter specification, such as a CD-ROM reader, and a
list of supported collection names or CD-ROM volume titles. This
provides the selection list when you Set Data Sources in GeoVu and may
be customized for your work. To do this, GeoVu provides the **Edit**
menu item **Data Source List**, which will create or modify the file. It
is also possible to read the file or to change it with a text editor.

Listed with each title is a specific file name, with a **.men**
extension, which is the menu file used by GeoVu to navigate through the
CD-ROM or data collection. Each line contains one title (any name you
want) followed by the separator **\#**, followed by the specific menu
file name. Since GeoVu Release 5 and newer: No path or drive letter or
home directory appears in the file names; these files must be in the
GeoVu installation directory (GEOVUDIR).

The menu files are distributed on CD-ROM and from **ftp.ngdc.noaa.gov**.
Corrections and updates may appear in the ftp directory. Copy these
files into your GeoVu installation directory. Not all data collections
have corresponding menu files. You may also wish to write one for your
data. See the *GeoVu Tools Reference Guide* for details.

The first line of the **cdm_serv.lst** file contains the keyword
**cd_driver** (the only keyword allowed in this file) followed by the
separator #, followed by the drive letter. The CD‑driver specification
in this file is optional. You can remove this line from the file or
change it to match your drive letter. Only one drive may be specified.
You can also enter or change the drive letter while running GeoVu when
using the menu item **Set Data Source**.

On Unix systems, this will not have a drive letter but rather the file
system name for the CD-ROM device or a directory path. On Macintosh the
**cd_driver** line in the file is not used, since each CD is accessed
directly using its volume name (i.e., the name of the CD appearing on
the desktop).

An example found on Windows of **cdm_serv.lst**:

cd_driver #L:

Gravity CD #gravcd.men

Global Change CD #global.men

This example file specifies that the CD-ROM Reader drive is L:, and two
CDs are currently supported: the Gravity CD and the Global Change CD.
GeoVu will expect to find the two corresponding **.men** files to be in
the GeoVu working directory.

An example found on UNIX platforms of **cdm_serv.lst**:

cd_driver #/cdrom0

Gravity CD #gravcd.men

Global Change CD #global.men

An example found on Macintosh of **cdm_serv.lst**:

Gravity CD #gravcd.men

Global Change CD #global.men

GeoVu will run without the **cdm_serv.lst** file. At start-up, GeoVu
will try to build the list of data sources by locating all menu files
(**.men**) in the GeoVu working directory (GEOVUDIR). If none are found,
then the only data source will be disk files.

## \@Menu (.men) Files

Menu Files describe the hierarchical file organization of a CD-ROM
volume or data collection. They may also include descriptive \"facts\"
text, data format specifications, header format specifications, and
naming equivalence tables. We use the file extension **.men** for the
menu file. Please read "Menu Files" and "GeoVu Keywords" in the *GeoVu
Tools Reference Guide* for detailed information.

For each CD-ROM data volume that GeoVu must access, there must be one
corresponding **.men** file. GeoVu menu files are distributed for many
NGDC CD-ROM volumes. To add the CD-ROM title to GeoVu\'s data sources
list, locate the menu file and update the data source list file using
GeoVu\'s **Edit** menu item **Data Source List**. This will customize
the list of available data sources you see in GeoVu.

Copy any **.men** files you have obtained on CD-ROM, diskette, or our
ftp location, into your GeoVu working directory. This works with all the
releases of GeoVu. Be sure that the files are converted into the native
text, having correct end-of-line characters. This is done automatically
when you use ftp in ASCII mode to get the files. On UNIX you can convert
PC menu files using a command of the form **tr -d'\\015'** **\<
*old.men* \> *new.men***. On Macintosh, drag the menu file onto the
Make-Mac EOL utility provided and choose the Mac EOL option.

## \@Format Specification (.afm, .bfm, .fmt) Files

GeoVu must be supplied with ***format specification files*** or
***format description files***, as defined in the *FreeForm User's
Guide***.** FreeForm is the Data Access module of GeoVu and is
documented separately, since GeoVu is only one of many applications that
use FreeForm. The user's guide describes the syntax and naming
conventions of the companion files which must be supplied along with
data files. These files are used by GeoVu when reading data, but if they
are not available GeoVu will try to use some default information.

## \@Formats list file stdform.nam

In order to read a file properly, GeoVu needs to know the data type and
data format and some GeoVu reserved words (keywords) must be given
meaningful equivalents. GeoVu searches for this information first in
accessory files found in the directory where the data file resides. If
the current data file is from a collection described in a GeoVu menu
file, GeoVu also searches sections of its corresponding menu file

If the necessary information is not found, GeoVu will display a list of
the standard formats from the file **stdform.nam** for you to select.
The **stdform.nam** file is an ASCII file which defines commonly-used
data formats, associating a name for the format type with the base
filename which is used to find the format information.

You may edit **stdform.nam** to add new formats. Each line in the
**stdform.nam** file contains two strings separated by a space. The
first string is the name you give the format, as it will appear on the
selection list of the Format Type dialog. The second part is the
corresponding base file name. GeoVu will use the base to compose format
file names and equivalence table file names it expects to find and use.
GeoVu expects the equivalence table file to reside in the GeoVu working
directory.

**Example: stdform.nam is shown below, as it is distributed with GeoVu**

AVHRR_GAC_1b_unpacked gac16

Binary_raster_user_defined user

ERDAS_raster erdas_ra

GEOVU_raster geovu_ra

IDRISI_raster_v3 idrisi_r

IDRISI_v4 idrisi4

McIDAS_PC_IMAGE mcidas_d

McIDAS_UNIX_IMAGE mcidas_u

PCX_Image pcx

UNKNOWN unknown

In the **stdform.nam** you see the GeoVu keyword: UNKNOWN, which is used
if the current data file is not in one of the standard formats.

Some standard file types cannot be described by FreeForm format
descriptions and GeoVu equivalence tables. They are not listed in
**stdform.nam** but may be understood by GeoVu only because of their
file extension; this is true for GIF files ending with **.gif**
extensions. Also supported are some types of **.hdf** files and **.mvv**
movie files.

## \@Name Table / Equivalence Table (.eqv) Files

Equivalence tables define and describe names used in a data file or used
by data files of one type, equating these names to reserved keywords
used in GeoVu. The text files that contain an equivalence table must
have the file extension **.eqv**. The contents may also be placed as a
section in a GeoVu menu file. Please see "Equivalence (Name) Tables"in
the *GeoVu Tools Reference Guide,* for details. Several **.eqv** files
are distributed with GeoVu: those used for the standard format types
entered in the **stdform.nam** file described above.

## \@GeoVu\'s Palettes List File

The palettes list file is an ASCII text file distributed with GeoVu that
contains a collection of color table definitions. At session start-up,
these tables (palettes) are available to GeoVu. Other palettes list
files may be supplied with CD-ROM data collections, and they may replace
the start-up color palettes during run-time. The menu files for those
collections may specify a file to use in place of the start-up palettes
file. You may also edit file **geopal.lst** to add or remove or change
color palettes.

This file is optional. Without this list file, GeoVu starts with only
two color palettes available: a 16 pure color VGA palette and a gray
scale 16 color palette.

The first line of each palette definition is \**palette_name*. Each name
found in the file will appear in the lists in GeoVu dialogs that control
your selection of color palettes. The color specification is a line of
four values separated by spaces: an index, red, green, and blue. The
value range for red, green, and blue is from 0 to 255. An example of
color palette:

0 55 0 67

1 0 0 45

2 0 0 63

3 0 0 95

4 0 0 127

5 0 0 159

6 0 0 191

7 31 0 223

8 0 131 195

9 0 191 131

10 0 187 79

11 0 255 0

12 139 255 0

13 207 255 0

14 255 255 127

15 255 255 255

This text can be placed in the palettes list file under its name or kept
in a separate file (we use the **.pal** extension). The separate palette
file can be linked into the palettes list file:

è To link the name of a palette to a **.pal** file on CD-ROM, the first
line of the color table is replaced by &*palette_file_name* (with a full
directory path but without CD-ROM drive letter).

è To link to a palette file in the GeoVu working directory, the first
line of the color table is replaced by \^*palette_file_name.*

An example from part of the **geopal.lst** file:

\*BGY

0 55 0 67

1 0 0 45

2 0 0 63

3 0 0 95

4 0 0 127

5 0 0 159

6 0 0 191

7 31 0 223

8 0 131 195

9 0 191 131

10 0 187 79

11 0 255 0

12 139 255 0

13 207 255 0

14 255 255 127

15 255 255 255

\*GVI

&\\1month\\mypals\\gvi.pal

\*QUAL

\^qual.pal

The file in the above example defines three palettes: BGY, GVI, and
QUAL. The palette BGY is defined directly; palette GVI is defined in the
CD-ROM file **\\1month\\mypals\\gvi.pal**; and palette QUAL is defined
in the file **qual.pal** in GeoVu working directory.