Pyxplot 
Examples  Surface with contours 
An example of a surface and contours on a 3D plot Pyxplot's surface plotting style evaluates a function at a grid of points in the xy plane, and draws a 3D surface showing how the function varies across the plane. Here, we also use the contours plotting style, which on a 3D plot draws contours on a function on the back face of the plot, here on the bottom xy plane of the plot cube. Scriptset xlabel "$x$" set ylabel "$y$" set zlabel "$x^3/20+y^2$" set nokey set size 6 square set nogrid plot 3d x**3/20+y**2 with surface col black fillc green, \ x**3/20+y**2 with contours col black
