# set terminal pngcairo  transparent enhanced font "arial,10" fontscale 1.0 size 600, 400 
# set output 'lambert.4.png'
set view 75, 281, 1.11607, 1.33952
set isosamples 30, 30
set style data lines
set xyplane at 0
set xtics border in scale 1,0.5 mirror norotate  offset character 0, -0.5, 0 autojustify
set ytics border in scale 3,1.5 mirror norotate  offset character 0, -1, 0 autojustify
set title "LambertW( x+{/:Italic i}y, k )" 
set title  font ",15" textcolor lt -1 norotate
set xrange [ -10.0000 : 10.0000 ] noreverse
set yrange [ -8.00000 : 12.0000 ] noreverse
set zrange [ 0.00000 : * ] noreverse noextend
set pm3d depthorder 
set pm3d interpolate 1,1 flush begin noftriangles border lt black linewidth 0.250 dashtype solid corners2color mean
unset colorbox
NO_ANIMATION = 1
splot for [k=0:4] abs(LambertW(x+y*{0,1}, k)) with pm3d lc k title sprintf("  k = %d",k) at end