#!/usr/local/bin/gnuplot -persist
# set terminal canvas  rounded size 600,400 enhanced fsize 10 lw 1.6 fontscale 1 name "pm3dcolors_5" jsdir "."
# set output 'pm3dcolors.5.js'
set format cb "%3.1f" 
unset key
set view map scale 1
set samples 101, 101
set isosamples 2, 2
set style function pm3d
set xtics  norangelimit 2
unset ytics
unset ztics
set cbtics  norangelimit 0.1
set title "set palette defined ( 20 \"#101010\", 30 \"#ff0000\", 40 \"#00ff00\", 50 \"#e0e0e0\" )" 
set xrange [ -10.0000 : 10.0000 ] noreverse nowriteback
set x2range [ * : * ] noreverse writeback
set yrange [ * : * ] noreverse writeback
set y2range [ * : * ] noreverse writeback
set zrange [ * : * ] noreverse writeback
set cbrange [ 0.00000 : 1.00000 ] noreverse nowriteback
set rrange [ * : * ] noreverse writeback
set palette defined ( 0 0.06275 0.06275 0.06275, 0.3333 1 0 0, 0.6667 0 1 0,\
     1 0.8784 0.8784 0.8784 )
set colorbox vertical origin screen 0.9, 0.2 size screen 0.05, 0.6 front  noinvert bdefault
g(x)=x
f(x)=(x+10)/20
splot f(x)