# set terminal pngcairo  transparent enhanced font "arial,10" fontscale 1.0 size 600, 400 
# set output 'heatmaps.6.png'
set bar 1.000000 front
set style circle radius graph 0.02, first 0.00000, 0.00000 
set style ellipse size graph 0.05, 0.03, first 0.00000 angle 0 units xy
set format cb "%4.1f" 
set style textbox transparent margins  1.0,  1.0 border
unset logscale
set view 49, 28, 1, 1.48
set samples 25, 25
set isosamples 50, 50
set xyplane relative 0
set cbtics border in scale 0,0 mirror norotate  autojustify
unset paxis 1 tics
unset paxis 2 tics
unset paxis 3 tics
unset paxis 4 tics
unset paxis 5 tics
unset paxis 6 tics
unset paxis 7 tics
set title "4D data (3D Heat Map)\nIndependent value color-mapped onto 3D surface" 
set title  offset character 0, 1, 0 font "" norotate
set xlabel "x" 
set xlabel  offset character 3, 0, 0 font "" textcolor lt -1 norotate
set xrange [ 5.00000 : 35.0000 ] noreverse nowriteback
set ylabel "y" 
set ylabel  offset character -5, 0, 0 font "" textcolor lt -1 rotate by -270
set yrange [ 5.00000 : 35.0000 ] noreverse nowriteback
set zlabel "z" 
set zlabel  offset character 2, 0, 0 font "" textcolor lt -1 norotate
set paxis 1 range [ * : * ] noreverse nowriteback
set paxis 2 range [ * : * ] noreverse nowriteback
set paxis 3 range [ * : * ] noreverse nowriteback
set paxis 4 range [ * : * ] noreverse nowriteback
set paxis 5 range [ * : * ] noreverse nowriteback
set paxis 6 range [ * : * ] noreverse nowriteback
set paxis 7 range [ * : * ] noreverse nowriteback
set pm3d implicit at s
set colorbox user
set colorbox vertical origin screen 0.9, 0.2, 0 size screen 0.03, 0.6, 0 front  noinvert noborder
sinc(x,y) = sin(sqrt((x-20.)**2+(y-20.)**2))/sqrt((x-20.)**2+(y-20.)**2)
Z(x,y) = 100. * (sinc(x,y) + 1.5)
color(x,y) = 10. * (1.1 + sin((x-20.)/5.)*cos((y-20.)/10.))
GPFUN_sinc = "sinc(x,y) = sin(sqrt((x-20.)**2+(y-20.)**2))/sqrt((x-20.)**2+(y-20.)**2)"
x = 0.0
GPFUN_Z = "Z(x,y) = 100. * (sinc(x,y) + 1.5)"
GPFUN_color = "color(x,y) = 10. * (1.1 + sin((x-20.)/5.)*cos((y-20.)/10.))"
## Last datafile plotted: "++"
splot '++' using 1:2:(Z($1,$2)):(color($1,$2)) with pm3d title "4 data columns x/y/z/color"