#
# 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 [-5:5]
set yrange [0.0:0.3]
set xtics out nomirror
set ytics in mirror format "%.2f"
set mxtics
set mytics
set sample 200

fwhm1 = VP_fwhm(1.53,0.0)
fwhm2 = VP_fwhm(1.30,0.5)
fwhm3 = VP_fwhm(1.00,1.0)
fwhm4 = VP_fwhm(0.00,1.8)

set style arrow 1 heads # size screen  0.008,90.,90.
set arrow 1 from -fwhm1/2., VP(-fwhm1/2., 1.53, 0.0) to fwhm1/2., VP(fwhm1/2., 1.53, 0.0) as 1 lc 1
set arrow 2 from -fwhm2/2., VP(-fwhm2/2., 1.30, 0.5) to fwhm2/2., VP(fwhm2/2., 1.30, 0.5) as 1 lc 2
set arrow 3 from -fwhm3/2., VP(-fwhm3/2., 1.00, 1.0) to fwhm3/2., VP(fwhm3/2., 1.00, 1.0) as 1 lc 3
set arrow 4 from -fwhm4/2., VP(-fwhm4/2., 0.00, 1.8) to fwhm4/2., VP(fwhm4/2., 0.00, 1.8) as 1 lc 4
set label 1 "FWHM" at 0, 0.07 center

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"


Click here for minimal script to generate this plot

unset arrow; unset label
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"


Click here for minimal script to generate this plot

unset key
set view map
set bmargin at screen 0.1
set tmargin at screen 0.9
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


Click here for minimal script to generate this plot

set encoding save_encoding