pm3d

pm3d is an splot style for drawing palette-mapped 3d and 4d data as color/gray maps and surfaces. It allows plotting gridded or non-gridded data without preprocessing. pm3d style options also affect solid-fill polygons used to construct other 3D plot elements.

Syntax (the options can be given in any order):

      set pm3d {
                 { at <position> }
                 { interpolate <steps/points in scan, between scans> }
                 { scansautomatic | scansforward | scansbackward
                                  | depthorder {base} }
                 { flush { begin | center | end } }
                 { ftriangles | noftriangles }
                 { clip {z} | clip1in | clip4in }
                 { {no}clipcb }
                 { corners2color
                   { mean|geomean|harmean|rms|median|min|max|c1|c2|c3|c4 }
                 }
                 { {no}lighting
                   {primary <fraction>} {specular <fraction>} {spec2 <fraction>}
                 }
                 { {no}border {retrace} {<linestyle-options>}}
                 { implicit | explicit }
                 { map }
               }
      show pm3d
      unset pm3d

Note that pm3d plots are plotted sequentially in the order given in the splot command. Thus earlier plots may be obscured by later plots. To avoid this you can use the depthorder scan option.

The pm3d surfaces can be projected onto the top or bottom of the view box. See pm3d position. The following command draws 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, set cbrange, set colorbox, and the demo file demo/pm3d.dem.