# set terminal pngcairo  transparent enhanced font "arial,10" fontscale 1.0 size 600, 400 
# set output 'function_block.1.png'
unset key
set label 1 "{/Times:Italic=12 Γ(x+iy) }{/Times:Normal=14  = exp(my\\_lngamma(x + y*I))}" at screen 0.5, 0.85, 0 center norotate back nopoint
set view 67, 317, 1, 1
set samples 71, 71
set isosamples 71, 71
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 xtics  norangelimit 1 
set ytics border in scale 1,0.5 mirror norotate  offset character 0, -0.5, 0 autojustify
set ytics  norangelimit 1 
set title "Example of using code in a function block" 
set title  font "Times,16" textcolor lt -1 norotate
set trange [ * : * ] noreverse nowriteback
set urange [ * : * ] noreverse nowriteback
set vrange [ * : * ] noreverse nowriteback
set xlabel "{/Times:Italic=16 x}" 
set xlabel  offset character -3, -1, 0 font "" textcolor lt -1 norotate
set xrange [ -3.50000 : 3.50000 ] noreverse nowriteback
set x2range [ * : * ] noreverse writeback
set ylabel "{/Times:Italic=16 iy}" 
set ylabel  offset character 5, -1, 0 font "" textcolor lt -1 rotate
set yrange [ -3.00000 : 3.00000 ] noreverse nowriteback
set y2range [ * : * ] noreverse writeback
set zrange [ 0.00000 : 7.00000 ] noreverse nowriteback
set cbrange [ * : * ] noreverse writeback
set rrange [ * : * ] noreverse writeback
set pm3d interpolate 1,1 flush begin noftriangles border lt black linewidth 0.500 dashtype solid corners2color mean
set colorbox vertical origin screen 0.9, 0.2 size screen 0.05, 0.6 front  noinvert bdefault
unset colorbox
my_lngamma(z) = (z == 0) ? NaN : (real(z) < 0.5) ? $Reflect(z) : $Lanczos(z)
Gamma(z) = exp( my_lngamma(z) )
NO_ANIMATION = 1
array coef[15] = [0.999999999999997,57.1562356658629,-59.5979603554755,14.1360979747417,-0.49191381609762,3.39946499848119e-05,4.65236289270486e-05,-9.83744753048796e-05,0.000158088703224912,-0.000210264441724105,0.000217439618115213,-0.000164318106536764,8.44182239838527e-05,-2.61908384015814e-05,3.68991826595316e-06]
splot abs(Gamma(x + y*I)) with pm3d fc "cyan"