#

# Exercise the special functions in external library libcerf.

# These are only present if libcerf was found during configuration/build

# of the current gnuplot executable.

#

if (!strstrt(GPVAL_COMPILE_OPTIONS,"+LIBCERF")) {

	print  "This copy of gnuplot was not linked against libcerf"

	exit;

}

save_encoding = GPVAL_ENCODING

set encoding utf8

set title "Voigt Profile VP(x,σ,γ)"

set xrange [-10:10]

set yrange [0.0:0.3]

set xtics out nomirror

set ytics in mirror format "%.2f"

set mxtics

set mytics

set sample 200

plot VP(x,1.53,0.0) title "σ=1.53 γ=0.00", \

     VP(x,1.30,0.5) title "σ=1.30 γ=0.50", \

     VP(x,1.00,1.0) title "σ=1.00 γ=1.00", \

     VP(x,0.00,1.8) title "σ=0.00 γ=1.80"

pause -1 "<cr> to continue"

set yrange [-1:1]

set title "Faddeeva/Voigt Function"

set key samplen 0.5

plot real( faddeeva(x) ) lw 2, \

     imag( faddeeva(x) ) lw 2, \

     real(cdawson(x)) lt -1 lw 0.5 title "Dawson's Integral"

pause -1 "<cr> to continue"

reset

unset key

set view map

set bmargin at screen 0.1

set sample 200

set isosamples 200, 200

set size ratio 1 1,1

set cbtics   ("0" -pi, "2π" pi)

set title "Complex error function cerf( x + iy )" 

set auto xy

set urange [ -3 : 3 ]

set vrange [ -3 : 3 ]

set tics scale 0

set cblabel "Phase Angle" 

set cblabel  offset character -2, 0, 0 font "" textcolor lt -1 rotate by -270

set cbrange [ -pi : pi ] noreverse nowriteback

set contour

set cntrparam levels discrete 0.1, 0.2, 0.5,  1, 2, 5,  10, 20, 50,  100, 200, 500

set cntrlabel onecolor

set palette positive nops_allcF maxcolors 0 gamma 1.5 color model HSV 

set palette defined ( 0 0 1 1, 1 1 1 1 )

Hue(x,y) = (pi + atan2(-y,-x)) / (2*pi)

phase(x,y) = hsv2rgb( Hue(x,y), sqrt(x**2+y**2), 1. )

rp(x,y) = real(f(x,y))

ip(x,y) = imag(f(x,y))

color(x,y) = hsv2rgb( Hue( rp(x,y), ip(x,y) ), abs(f(x,y)), 1. )

f(x,y) = cerf(x+y*{0,1})

splot '++' using 1:2:(color($1,$2)) with pm3d lc rgb variable nocontour, \

      '++' using 1:2:(abs(cerf($1+$2*{0,1}))) with lines nosurf lt -1

pause -1 "<cr> to continue"

reset

set encoding save_encoding