# set terminal png transparent nocrop enhanced font arial 8 size 420,320 
# set output 'pm3d.30.png'
set border 4095 lt -1 lw 1.000
set format cb "%.01t*10^{%T}"
set samples 31, 31
set isosamples 31, 31
unset surface
set ticslevel 0
set title "only for enhanced terminals: 'set format cb ...'" 0.000000,0.000000  font ""
set xlabel "X" 0.000000,0.000000  font ""
set xrange [ -185.000 : 185.000 ] noreverse nowriteback
set ylabel "Y" 0.000000,0.000000  font ""
set yrange [ -185.000 : 185.000 ] noreverse nowriteback
set cblabel "the colour gradient" 0.000000,0.000000  font ""
set pm3d at s
set pm3d scansautomatic flush begin noftriangles nohidden3d solid implicit corners2color mean
set palette positive nops_allcF maxcolors 0 gamma 1.5 gray
splot abs(x)**3+abs(y)**3