f(x,y) = 3*(1-x)**2*exp(-x**2 - (y+1)**2)\
        - 10*(x/5.0 - x**3 - y**5)*exp(-x**2 - y**2)\
        - exp(-(x+1)**2 - y**2)/3
set style lines 100 lt -1 lw 0.2 lc rgb "black"
set pm3d hidden3d 100 explicit
set samples 50
set isosamples 50
unset key
set label "{/Helvetica=18 splot with pm3d (hidden3d)}" at sc 0.2,0.9
set xlabel "£Ø¼´" font "GothicBBB-Medium-EUC-H,12"
set ylabel "£Ù¼´" font "Ryumin-Light-EUC-H,12"
set zlabel "£Ú¼´" font "GothicBBB-Medium-EUC-H,12"
set ticslevel 0
set term pngcairo enh font "Times,10" size 480,360
set out "mesh_pm3d_hidden.png"
splot [-3:3][-3:3] f(x,y) w pm3d