gnuplot documentation

126 gnuplot 4.3 70 SET-SHOW
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 of
use e.g.
set palette defined ( 0 0 0 0, 1 1 1 1 )
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
well enough.
70.50.6 Postscript
In order to reduce the size of postscript files, the gray value and not all three calculated r,g,b values
are written to the file. Therefore the analytical formulae are coded directly in the postscript language
as a header just before the pm3d drawing, see /g and /cF definitions. Usually, it makes sense to write
therein definitions of only the 3 formulae used. But for multiplot or any other reason you may want to
manually edit the transformations directly in the postscript file. This is the default option nops allcF.
Using the option ps allcF writes postscript definitions of all formulae. This you may find interesting if
you want to edit the postscript file in order to have different palettes for different surfaces in one graph.
Well, you can achieve this functionality by multiplot with fixed origin and size.
If pm3d map has been plotted from gridded or almost regular data with an output to a postscript file,
then it is possible to reduce the size of this postscript file up to at about 50% by the enclosed awk script
pm3dCompress.awk. This you may find interesting if you intend to keep the file for including it into
your publication or before downloading a very large file into a slow printer. Usage:
awk -f pm3dCompress.awk thefile.ps >smallerfile.ps
If pm3d map has been plotted from rectangular gridded data with an output to a postscript file, then it
is possible to reduce the file size even more by the enclosed awk script pm3dConvertToImage.awk.
Usage:
awk -f pm3dConvertToImage.awk smallerfile.ps
You may manually change the postscript output from gray to color and vice versa and change the
definition of .
70.50.7 Colornames
Gnuplot knows a limited number of color names. You can use these to define the color range spanned
by a pm3d palette, or to assign a terminal-independent colot to a particular linetype or linestyle. To see
the list of know color names, use the command show palette colornames (p. 126). See set palette
(p. 122), linestyle (p. 133).
70.51 Pointsize
The set pointsize command scales the size of the points used in plots.
Syntax:
set pointsize
show pointsize
The default is a multiplier of 1.0.
bitmapped graphics.
Larger pointsizes may be useful to make points more visible in
The pointsize of a single plot may be changed on the plot command. See plot with (p. 79) for details.
Please note that the pointsize setting is not supported by all terminal types.