# set terminal png transparent nocrop enhanced font arial 8 size 420,320 
# set output 'pm3d.39.png'
unset border
unset key
set view map
set samples 4, 4
set isosamples 4, 4
set size ratio 0 0.333333,0.333333
set origin 0.333333,0.333333
set noxtics
set noytics
set title "Original grid points" 0.000000,0.000000  font ""
set xrange [ 0.00000 : 3.00000 ] noreverse nowriteback
set yrange [ 0.00000 : 3.00000 ] reverse nowriteback
set y2range [ * : * ] reverse nowriteback  # (currently [-10.0000:10.0000] )
set cbrange [ 0.00000 : 9.00000 ] noreverse nowriteback
set pm3d scansautomatic flush begin noftriangles nohidden3d transparent implicit corners2color median
unset colorbox
sinc(u,v) = sin(sqrt(u**2+v**2)) /sqrt(u**2+v**2)
f(x,y)=2*x+y
dx = 0.333333333333333
dy = 0.333333333333333
splot f(x,y) with linesp ps 3 pt 5 palette