# set terminal svg size 600,400 dynamic enhanced fname 'arial'  fsize 10 mousing name "pm3d_4" butt dashlength 1.0 
# set output 'pm3d.4.svg'
set bar 1.000000 front
set border 4095 front lt black linewidth 1.000 dashtype solid
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 style textbox transparent margins  1.0,  1.0 border
unset logscale
set samples 25, 25
set isosamples 20, 20
unset surface 
set style data lines
set xyplane relative 0
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 "unset surface; set pm3d at st (surface and top)" 
set xlabel "x" 
set xrange [ -15.0000 : 15.0000 ] noreverse nowriteback
set ylabel "y" 
set yrange [ -15.0000 : 15.0000 ] noreverse nowriteback
set zrange [ -0.250000 : 1.00000 ] noreverse nowriteback
set cblabel "colour gradient" 
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 st
set colorbox vertical origin screen 0.9, 0.2, 0 size screen 0.05, 0.6, 0 front  noinvert bdefault
splot sin(sqrt(x**2+y**2))/sqrt(x**2+y**2)