# set terminal png transparent nocrop enhanced font arial 8 size 420,320 
# set output 'pm3d.21.png'
set border 4095 front linetype -1 linewidth 1.000
set style line 100  linetype 5 linewidth 0.500 pointtype 100 pointsize default
set samples 20, 20
set isosamples 20, 20
unset surface
set size ratio 0 0.6,0.6
set origin 0.2,0.25
set ticslevel 0
set nomcbtics
set title "color box is switched off" 
set xrange [ * : * ] noreverse nowriteback  # (currently [-1.00000:1.00000] )
set yrange [ * : * ] noreverse nowriteback  # (currently [-1.00000:1.00000] )
set zrange [ * : * ] noreverse nowriteback  # (currently [-15.0000:60.0000] )
set cbrange [ * : * ] noreverse nowriteback  # (currently [-15.0000:4.00000] )
set pm3d implicit at s
unset colorbox
splot y