gnuplot documentation

70 SET-SHOW gnuplot 4.3 121
splot x*x+y*y
There used to be an option {transparent|solid} to this command. Now you get the same effect from set
grid {front|layerdefault}, respectively.
The set pm3d map is an abbreviation for set pm3d at b; set view map; set style data pm3d;
set style func pm3d;. It is used for backwards compatibility, when set view map was not available.
Take care that you properly use zrange and cbrange for input data point filtering and color range
scaling, respectively; and also set (no)surface seems to have a (side?) effect.
The option interpolate will interpolate grid points into a finer mesh, and color each quadrangle appropriately.
For data files, this will smoothen the color surface, and enhance spikes in a color surface. For
functions, interpolation makes little sense, except to trade off precision for memory. It would usually
make more sense to use samples and isosamples when working with functions.
The coloring setup as well as the color box drawing are determined by set palette. There can be only
one palette for the current plot. Drawing of several surfaces with different palettes can be achieved by
multiplot with fixed origin and size; don’t forget to use set palette maxcolors when your terminal
is running out of available colors.
On gnuplot start-up, mode is explicit. For historical and thus compatibility reasons, commands set
pm3d; (i.e. no options) and set pm3d at X ... (i.e. at is the first option) sets mode implicit. Further,
set pm3d; sets up the other options to their default.
If the option implicit is on, all surface plots will be plotted additionally to the default type, e.g.
splot ’fred.dat’ with lines, ’lola.dat’ with lines
would give both plots (meshes) additionally to a pm3d surface. That’s what you are used to after set
pm3d;.
If the option explicit is on (or implicit 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 (and only lines) and ’lola.dat’ with a pm3d surface.
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.
Note that when plotting several plots, they are plotted in the order given on the command line. This can
be of interest especially for filled surfaces which can overwrite and therefore hide part of earlier plots.
If with pm3d is specified in the splot command line, then it accepts the ’at’ option. The following
plots draw 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. 122), set cbrange (p. 149), set colorbox (p. 93), x11 pm3d
(p. 204) and definitely the demo file demo/pm3d.dem.
70.49.1 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 options
scansautomatic|scansforward|scansbackward. These scan options are not in general compatible
with hidden-surface removal.
Gnuplot does not do true hidden surface removal for solid surfaces, but often it is sufficient to render the
component quadrangles in order from furthest to closest. This mode may be selected using the options
set pm3d depthorder hidden3d
The depthorder option orders the solid quadrangles; the hidden3d option similarly orders the bounding
lines (if drawn). Note that the global option set hidden3d does not affect pm3d surfaces.