2D projections of 3D data

In most cases of $3$D plot you can rotate the coordinate system as much as you want in any direction but never get a good overview of all data provided.

This problem can be circumvented by depicting the $3$rd dimension by something else than an additional spatial dimension in the underlying coordinate system. A possibility to do so is for example color- or intensity-coding using gradients and/or step functions.

You can do this easily in gnuplot by setting the pm3d option (palette mapped 3D). NOTE that this feature can only be used when our data is converted into a grid as we did before with dgrid3d

First consult the help provided with

gnuplot> help pm3d

Then make a first color coded plot by typing

gnuplot> set pm3d
gnuplot> replot

Deactivating the color encoded third dimension again is done by entering

gnuplot> unset pm3d

It is also posssible to make a map of the color encoded $3$D data at the bottom of the graph with

gnuplot> set pm3d at b

To hide the lines of the graph and only show the pm3d generated color encoding, you can type

gnuplot> set hidden3d
gnuplot> replot

For additional features visit the following webpage again:
http://t16web.lanl.gov/Kawano/gnuplot/index-e.html