# set terminal pngcairo background "#ffffff" font "arial,10" fontscale 1.0 size 500, 300 # set output 'hidden2.1.png' set style fill solid 0.50 border unset key set isosamples 25, 25 set hidden3d front offset 1 trianglepattern 3 undefined 1 altdiagonal bentover set xyplane at 0 set title "Mixing pm3d surfaces with hidden-line plots" set cbrange [ -1.00000 : 1.00000 ] noreverse nowriteback set palette rgbformulae 31, -11, 32 f(x,y) = sin(-sqrt((x+5)**2+(y-7)**2)*0.5) GPFUN_f = "f(x,y) = sin(-sqrt((x+5)**2+(y-7)**2)*0.5)" splot f(x,y) with pm3d, x*x-y*y with lines lt 1 lc rgb "#000000", f(x,y) with lines lt -2 notitle