# set terminal pngcairo  background "#ffffff" enhanced font "arial,10" fontscale 1.0 size 600, 400 
# set output 'pm3d.42.png'
set border 895 front linetype -1 linewidth 1.000
set samples 40, 40
set isosamples 40, 40
set ticslevel 0
set title "coloring according to the 3rd 'using' parameter (left) and to the z-value (bottom)" 
sinc(u,v) = sin(sqrt(u**2+v**2)) /sqrt(u**2+v**2)
GPFUN_sinc = "sinc(u,v) = sin(sqrt(u**2+v**2)) /sqrt(u**2+v**2)"
splot     'binary2' binary u 2:(12 - column(3) * 10):1 notitle w lines,     'binary2' binary u (-12 + column(3) * 10):2:1:(-12 + column(3) * 10) notitle w pm3d,     'binary2' binary u 1:2:(column(3) * 10 - 12) notitle w pm3d