# set terminal pngcairo  background "#ffffff" enhanced font "arial,10" fontscale 1.0 size 600, 400 
# set output 'pm3d.41.png'
set samples 40, 40
set isosamples 40, 40
set ticslevel 0
set title "pm3d explicit mode --- coloring according to the 4th parameter of 'using'" 
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 1:2:3:($2+($1+$2)/10) w pm3d, 	1+sinc(x*4, y*4) w l