## use "python make-surface-file.py > surface.dat" to prepare the file
## then try these commands from within gnuplot:
splot 'surface.dat' using 1:2:3
set hidden3d
splot 'surface.dat' using 1:2:3 with lines
set pm3d
set contour base
set style data lines
splot 'surface.dat' using 1:2:3