GD

Name:

GD Type:

Output Device Command Purpose:

Create PNG, JPEG, GIF, BMP and TIFF format graphics files. Description:

Dataplot implements these formats using the GD library. The GD library was originally developed by Thomas Boutell. It is now maintained and developed as an open source library. The web page for GD is located at

https://libgd.github.io/

and the source code can be downloaded at

https://github.com/libgd/libgd/releases

The GD library is used by the popular PHP, Perl and Ruby software programs (as well as other programs), so it will be available on most Linux/Unix platforms. If it is not already installed, there are packages for the most common Linux/Unix distros.

Dataplot is not particularly sensitive to which version of the GD library you have on your system. Any reasonably current version should suffice. The major restriction is that GD 1.x versions are no longer supported (GD changed some calling sequences in moving to the 2.x versions). The Dataplot code is now updated to use the 2.x calling sequence This change was made in the 03/2006 version of Dataplot.

Syntax:

This form designates one of DATAPLOT's 3 devices as an GD device. For the GD device, DEVICE 2 is typically used.

Examples:

Note:

DATAPLOT must be linked with the proper GD libraries in order for the GD driver to work. If this is not the case, contact your local DATAPLOT installer. Note:

added support for the BMP format. This device was available in previous versions of GD, but I had not activated it for Dataplot. BMP is a common format in the Windows environment.
added support for the WBPM format. This device was available in previous versions of GD, but I had not activated it for Dataplot. WBMP is a black and white format that was originally intended for mobile/wireless applications. It is not commonly used anymore.
added support for TGA (Targa format). Note that this format is coded but has not been tested.
added support for TIFF. Note that this option requires that the "libtiff" library be installed, so this format may not be available in some Dataplot installations.
the webp format is supported if the VPX library is available. This is a relatively new format championed by Google. It is primarily intended for viewing videos on the web. This format will probably not be available on most Dataplot installations.

Version 2.3.2 added support for the AVIF and HEIF formats. We have not yet updated Dataplot to support these formats.

Be aware that some of these formats require external libraries that may not be available with the version of the GD library installed on your local platform.

The basic GD implementation uses the libraries: zlib, libpng, libjpeg, and libfreetype. These should be included with most GD installations. The libtiff library is typically available on most Linux platforms. However, the libraries for the webp, AVIF and HEIF formats are less likely to be available.

Note:

Dataplot can generate Postscript (PDF files can be generated using Ghostscript) and Scalable Vector Graphics (SVG) graphics files. Using the open source GIMP software, the Postscript or SVG file can be converted to a number of different common image formats. The advantage of this method is that it maintains the high quality of the original Postscript/SVG file (GIMP uses anti-aliasing when converting from a vector format to a bit map format). The disadvantage is that it requires an additional manual step.
There are other software programs that can convert Postscript/SVG to bit map formats. However, not all of these programs perform anti-aliasing, so the quality may vary.
The Windows version of Ghostview can convert Postscript/PDF files to JPEG.
Either Ghostscript or the ImageMagick convert program can be used to automatically convert Dataplot's Postscript output to JPEG, TIFF, PDF, PBM, PGM, PPM or PNM. For details, enter
The Dataplot CAIRO device driver supports PNG. However this driver is still in "beta" mode.

Note:

The SET IPL1NA command specifies the name of the file. Note that this name is currently converted to upper case. This command should come before the DEVICE 2 GD command.

Note:

There are 5 built-in fonts: TINY, SMALL, MEDIUM, LARGE, or GIANT. These will be available for all GD installations. These are fixed size fonts.
GD supports the use of True Type fonts using the Free Type library. If you have True Type fonts (these fonts are identified with a ".ttf" file extension) installed on your system, you can specify that Dataplot use these fonts with the command
Note that you must specify the full path name for the font name. For example
There are several ways to locate or obtain True Type fonts.
- Dataplot provides a limited number of True Type fonts in the "fonts" directory in the Dataplot auxilary files directory. On Linux systems, this is often one of
  On Windows platforms, this is
- Many platforms will have libraries of True Type fonts already installed.
  For example, on the Red Hat Enterprise version 8 (including derivative CentOS and Rocky) Linux system, a number of True Type fonts are availabe in
  There are a number of sub-directories under this that contain the fonts. For example the "gnu-free" sub-directory contains the following fonts
  These directories contain some fonts with ".ttf" file name extensions and some with ".otf" file name extensions. Only the ".ttf" font files should be used with the GD driver.
  Under Windows 10, many fonts are stored in the
  directory. True Type fonts are identified with a ".ttf" file name extension. Note that you free to use these fonts with Dataplot. However, Microsoft does not grant re-distribution rights, so none of these are included in the Dataplot "fonts" directory.
- There are both commercial and freely downloadable True Type fonts available on the Internet.

Note:

To specify the color model, enter

SET GD COLOR <TRUE/FIXED>

The default is FIXED. The TRUE mode is recommended if you are going to be generating image plots. Otherwise the FIXED option should be sufficient for most applications.

Note:

HELP READ IMAGE

Note:

Dashed and dotted lines now work.
Region fills were fixed. Rectangular regions are performed in hardware (i.e., by the GD library) while non-rectangular fills are performed in software (i.e., by Dataplot).
The following command was added
The default is OFF and this is recommended. The ON option is currently intended for testing purposes and it is recommended that this option be left as OFF. The ON option specifies that non-rectangular regions be filled in hardware.
Fixed the background color when true color mode is specified.

Default:

If no device is specified, the default device is PNG. Synonyms:

None Device Notes:

HARDWARE TEXT - the GD driver supports 5 built-in fonts. In addition, True Type fonts are supported if available. The True Type font can be specified with the
command.
COLOR - GD supports the full range of 163 colors supported by Dataplot. Full RGB coor is supported in true color mode.
HARDWARE FILL - Solid area fills for rectangles are performed in hardware (i.e., by the GD library) and non-rectangular fills are performed in software (i.e., by Dataplot).
DASH PATTERNS - The following dash patterns are available:
- DASH - 3 pixels on, 3 pixels off;
- DOT - 1 pixel on, 1 pixels off;
- DASH2 - 4 pixels on, 2 pixels off
- DASH3 - 3 pixels on, 3 pixels off, 1 pixel on, 1 pixel off;
- DASH4 - 2 pixels on, 2 pixels off.
- DASH5 - 2 pixels on, 1 pixels off, 1 pixel on, 1 pixel off;
LINE WIDTH - Thick lines are generated in software (i.e., by Dataplot).
GRAPHICS INPUT - The CROSS-HAIR command is not supported
for this device.
The CHARACTER PIXEL option is supported on this device.

Related Commands:

POSTSCRIPT	= Direct graphical output to a Postscript device.
SVG	= Generate graphical output in Scalable Vector Graphics format.
DEVICE	= Specify certain actions for the graphics output.

Applications:

Web Applications, Graphics Import Into Other Programs Implementation Date:

Program 1:

 
background color yellow
. Following path name is for a Rocky 8 system
set gd font /usr/share/fonts/gnu-free/FreeSansBold.ttf
set ipl1na gd.jpg
device 2 gd jpeg
device 2 font tektronix
.
char hw 1 0.75 2 1.5
char x y
char color blue red
line color blue red
.
title offset 2
title Sample Plot
title case asis
y1label y axis
x1label x axis
label color green
title color green
.
legend 1 direction vertical
legend 1 just lece
legend 1 coordinates 55 22
legend 1 left
legend 2 direction vertical
legend 2 just cece
legend 2 coordinates 55 32
legend 2 center
legend 3 direction vertical
legend 3 just rice
legend 3 coordinates 55 42
legend 3 top
.
plot x    for x = 1 1 9 and
plot x**2 for x = 1 1 9
.
just lebo
move 25 75
text Bottom
just cece
move 35 75
text Center
just rito
move 45 75
text Top
draw 25 75 55 75
draw 25 80 25 70
draw 35 80 35 70
draw 45 80 45 70
.
draw 50 22 60 22
draw 50 32 60 32
draw 50 42 60 42
device 2 close

Program 2:

 
background color yellow
. Path name for font will be implementation dependent
set gd font /usr/local/lib/dataplot/fonts/futuram.ttf
set ipl1na gd2a.jpg
device 2 gd jpeg
device 2 font tektronix
.
char hw 1 0.75 2 1.5
char circle box
char color blue red
char fill on on
line solid solid
line color blue ivory
.
grid on
xgrid pattern dotted
ygrid pattern dashed
.
title offset 2
title Test Filled Characters/Futuram Font
title case asis
y1label y axis
x1label x axis
.
plot x    for x = 1 1 9 and
plot x**2 for x = 1 1 9
.
box shadow hw 0 0
box fill pattern solid
box fill color red
box 20 70 30 85
grid off
.
device 2 close

 
background color white
. Path name for font will be implementation dependent
set gd font /usr/local/lib/dataplot/fonts/arial.ttf
set ipl1na gd2b.jpg
device 2 gd jpeg
device 2 font tektronix
.
line color black black
line da3 da5
.
title offset 2
title Test Dash and Dot Lines/Arial Font
title case asis
y1label y axis
x1label x axis
.
plot x    for x = 1 1 9 and
plot x**2 for x = 1 1 9
.
device 2 close

 
background color white
set ipl1na gd2c.jpg
. Path name for font will be implementation dependent
set gd font /usr/local/lib/dataplot/fonts/Tahoma.ttf
device 2 gd jpeg
device 2 font tektronix
.
line solid solid
line thickness 0.2 0.3
.
title offset 2
title Test Line Thickness/Tahoma Font
title case asis
y1label y axis
x1label x axis
.
plot x    for x = 1 1 9 and
plot x**2 for x = 1 1 9
.
device 2 close

 
set gd color true
background color blue
. Path name for font will be implementation dependent
set gd font /usr/share/fonts/gnu-free/FreeSerifBold.ttf
set ipl1na gd2d.jpg
device 2 gd jpeg
device 2 font tektronix
.
frame color yellow
tic mark color yellow
tic mark label color yellow
title color cyan
label color cyan
.
line solid solid
line thickness 0.3 all
line color blue red
line rgb color 86 180 233 204 121 167
character size 3 3
character box circle
character fill on on
character rgb color 86 180 233 204 121 167
.
title offset 2
title Test True Color Mode/Serif Bold Font
title case asis
y1label y axis
x1label x axis
.
plot x    for x = 1 1 9 and
plot x**2 for x = 1 1 9
.
device 2 close

 
set gd color true
background rgb color 50 98 211
. Path name for font will be implementation dependent
set gd font /usr/share/fonts/gnu-free/FreeSans.ttf
set ipl1na gd2e.jpg
device 2 gd jpeg
device 2 font tektronix
.
frame color yellow
tic mark color yellow
tic mark label color yellow
title color cyan
label color cyan
.
line solid solid
line thickness 0.3 all
line color blue red
line rgb color 86 180 233 204 121 167
character size 3 3
character box circle
character fill on on
character rgb color 86 180 233 204 121 167
.
title offset 2
title Test True Color Mode/Sans Font
title case asis
y1label y axis
x1label x axis
.
plot x    for x = 1 1 9 and
plot x**2 for x = 1 1 9
.
device 2 close