CTAN sync 202408230303

9 files changed, 123 insertions, 144 deletions

diff --git a/macros/luatex/latex/domaincoloring/Changes b/macros/luatex/latex/domaincoloring/Changes
index 1498297672..e49a69aac3 100644
--- a/macros/luatex/latex/domaincoloring/Changes
+++ b/macros/luatex/latex/domaincoloring/Changes
@@ -1 +1,4 @@
-0.01  2024-08-21  - first CTAN version
+0.02  2024-08-22  - edit option bgcolor
+                  - reduced header for the intermediate eps
+                  - renamed complex-numbers.lua
+0.01  2024-08-18  - first CTAN version
diff --git a/macros/luatex/latex/domaincoloring/README.md b/macros/luatex/latex/domaincoloring/README.md
index 3a57b45ee4..9cff64e2f1 100644
--- a/macros/luatex/latex/domaincoloring/README.md
+++ b/macros/luatex/latex/domaincoloring/README.md
@@ -2,9 +2,11 @@
 Package domaincoloring creates a colored
 representation of the domain of complex function. 
 
+The package needs lualatex and does not work with pdflatex or xelatex!
 
-%% This file is distributed under the terms of the LaTeX Project Public
-%% License from CTAN archives in directory  macros/latex/base/lppl.txt.
-%% Either version 1.3 or, at your option, any later version.
+%% This program can be redistributed and/or modified under the terms
+%% of the LaTeX Project Public License Distributed from CTAN archives.
+%% The latest version of this license is in
+%%    http://www.latex-project.org/lppl.txt
 
 hvoss@tug.org
\ No newline at end of file
diff --git a/macros/luatex/latex/domaincoloring/doc/domaincoloring-doc.pdf b/macros/luatex/latex/domaincoloring/doc/domaincoloring-doc.pdf
index 19e3b30033..8a8b79e4d9 100644
--- a/macros/luatex/latex/domaincoloring/doc/domaincoloring-doc.pdf
+++ b/macros/luatex/latex/domaincoloring/doc/domaincoloring-doc.pdf
diff --git a/macros/luatex/latex/domaincoloring/doc/domaincoloring-doc.tex b/macros/luatex/latex/domaincoloring/doc/domaincoloring-doc.tex
index 80377e25ae..63c33ec368 100644
--- a/macros/luatex/latex/domaincoloring/doc/domaincoloring-doc.tex
+++ b/macros/luatex/latex/domaincoloring/doc/domaincoloring-doc.tex
@@ -1,59 +1,41 @@
-%% $Id: domaincoloring-doc.tex 945 2024-08-21 19:30:48Z herbert $
+%% $Id: domaincoloring-doc.tex 952 2024-08-22 15:40:35Z herbert $
 % 
-% Copying and distribution of this file, with or without modification,
-% are permitted in any medium, without royalty.
+\listfiles
 
+\DocumentMetadata{}
+\documentclass[fontsize=11pt,english,BCOR=10mm,DIV=12,bibliography=totoc,parskip=false,headings=small,
+    headinclude=false,footinclude=false,oneside]{pst-doc}
 \listfiles
-\PassOptionsToPackage{table}{xcolor}
-\documentclass[fontsize=11pt,paper=a4,twoside=on,abstract=on,usegeometry]{scrartcl}
-\usepackage[bmargin=1cm,tmargin=1cm,includeheadfoot]{geometry}
-
-\usepackage{unicode-math}
-\usepackage[RM={Scale=0.94},
-            SS={Scale=0.94},
-            SScon={Scale=0.94},
-            TT={Scale=MatchLowercase,FakeStretch=0.9},
-            DefaultFeatures={Ligatures=TeX}]{libertinus-otf}
-\setmonofont{AnonymousPro}[FakeStretch=0.9,Scale=MatchLowercase]
-\usepackage[english]{babel}
-%\usepackage[autostyle]{csquotes}
-%\DeclareQuoteStyle{polish}{,,}{''}{«}{»}
 
 \usepackage{biblatex}
 \addbibresource{\jobname.bib}
-\usepackage{array,multido}
-\usepackage{metalogo} % for \XeTeX logo
+
 \usepackage{booktabs} % for examples
 \usepackage{xltabular} % for examples
 \usepackage{enumitem}
 \setlist{noitemsep,nosep}
+
 \usepackage{domaincoloring}
+\let\DColFV\fileversion
 
-\usepackage{multicol,hvlogos} % for Wikipedia W
+\usepackage{hvlogos} 
 
 \usepackage{listings}
 \lstset{columns=fixed,basicstyle=\ttfamily\small}
 
-\pagestyle{headings}
-
-\usepackage[colorlinks,hyperfootnotes=false]{hyperref}
-% define \code for url-like breaking of typewriter fragments.
-\ifx\nolinkurl\undefined \let\code\url \else \let\code\nolinkurl \fi
-
-% Define \cs to prepend a backslash, and be unbreakable:
-\DeclareRobustCommand\cs[1]{\mbox{\texttt{\char`\\#1}}}
-
-\let\Lkeyword\texttt
+\def\bgImage{\includegraphics[width=7cm]{titleImg}}
 
-\title{Domain Coloring of complex functions}
+\title{Domain Coloring of complex functions\\version \DColFV}
 \author{Herbert Voß}
 \begin{document}
-\maketitle
+\settitle
 \tableofcontents
 
 
 \section{Introduction}
 
+This package works only with \texttt{lualatex}!
+
 \subsection{Loading the package}
 The package \texttt{domaincoloring} creates acolored interpretation of the
 domain of a complex function. The package itself has no options and should be loaded as
@@ -67,7 +49,7 @@ The needs the following Lua modules:
 
 \begin{itemize}
 \item \texttt{domaincoloring.lua}   the main module
-\item \texttt{complex-numbers.lua} for complex math operations
+\item \texttt{domaincoloring-complex-numbers.lua} for complex math operations
 \item \texttt{domaincoloring-functions.lua}   for predefined complex functions
 \end{itemize}
 
@@ -84,11 +66,11 @@ ppm-file into a png file..
 
 
 \begin{verbatim}
-\DomainColoring[options]{complex function}
+\DomainColoring[options]{complex function in Lua notation}
 \end{verbatim}
 
+Every math function has to be preceeded by \texttt{cmath} if it has a complex argument.
 
-\clearpage
 \subsection{Options}
 
 \noindent
@@ -98,16 +80,19 @@ domain & {-2,2,-2,2} & the (re,im)-coordinates for the complex system\\
 resolution & 500 & the number of steps for the re,im interval. At the moment only
 for both coordinates the same. Will be in future
 versions different for the both axes. \\
-filename & \cs{jobname-tmp} & name of the created external file, must be unique\\ 
-grfOptions &scale=0.5 & optional arguments for \cs{includegraphics}\\
+filename & \Lcs{jobname-tmp} & name of the created external file, must be unique\\ 
+grfOptions &scale=0.5 & optional arguments for \Lcs{includegraphics}\\
 hsvrgb & {phi,1,r} & for the conversion into rgb\\
 funcName & & corresponding to external file\\
-bgcolor & false & change black to white as background\\
-invers & false & invers colors with $color=|color-255|$\\
+bgcolor & 0 & change color to white as background for all values $r+g+b\le\text{bgcolor}$\\
+invers & false & inverted colors with $color=|color-255|$\\
 \bottomrule
 \end{xltabular}
 
-\section{examples}
+
+
+
+\section{Examples}
 
 \subsection{The default with function $f(z)=z$}
 \begin{lstlisting}
@@ -119,20 +104,26 @@ invers & false & invers colors with $color=|color-255|$\\
 %\DomainColoring[filename=demo2.png,bgcolor=true]{z}
 
 
-\clearpage
 
 \subsection{Defining domain, color mode, resolution and filename}
+
+\begin{align}
+ f(z) &= \cos(z)/\sin(z^4-1)
+\end{align}
+
+in Lua-notation: \verb|cmath.cos(z)/cmath.sin(z^4-1)|.
+
 \begin{lstlisting}
 \DomainColoring[domain={-2.5,2.5,-2.5,2.5},resolution=500,
     grfOptions={width=0.32\linewidth},
     filename=\jobname-tmp1a]{cmath.cos(z)/cmath.sin(z^4-1)}
 \hfill
 \frame{\DomainColoring[domain={-2.5,2.5,-2.5,2.5},resolution=500,
-    bgcolor=true,grfOptions={width=0.32\linewidth}
+    bgcolor=true,grfOptions={width=0.32\linewidth},bgcolor=3,
     filename=\jobname-tmp1b]{cmath.cos(z)/cmath.sin(z^4-1)}}
 \hfill
 \frame{\DomainColoring[domain={-2.5,2.5,-2.5,2.5},resolution=500,
-    invers=true,,grfOptions={width=0.32\linewidth}
+    invers=true,,grfOptions={width=0.32\linewidth},
     filename=\jobname-tmp1c]{cmath.cos(z)/cmath.sin(z^4-1)}}
 \end{lstlisting}
 
@@ -140,13 +131,18 @@ invers & false & invers colors with $color=|color-255|$\\
 \DomainColoring[domain={-2.5,2.5,-2.5,2.5},resolution=500,grfOptions={width=0.32\linewidth},
     filename=\jobname-tmp1a]{cmath.cos(z)/cmath.sin(z^4-1)}
 \hfill
-\frame{\DomainColoring[domain={-2.5,2.5,-2.5,2.5},resolution=500,bgcolor=true,grfOptions={width=0.32\linewidth},
+\frame{\DomainColoring[domain={-2.5,2.5,-2.5,2.5},resolution=500,bgcolor=3,grfOptions={width=0.32\linewidth},
     filename=\jobname-tmp1b]{cmath.cos(z)/cmath.sin(z^4-1)}}
 \hfill
 \frame{\DomainColoring[domain={-2.5,2.5,-2.5,2.5},resolution=500,invers=true,grfOptions={width=0.32\linewidth},
     filename=\jobname-tmp1c]{cmath.cos(z)/cmath.sin(z^4-1)}}
 
-\subsection{Option for \cs{includegraphics}}
+
+With \Lcs{bgcolor}\texttt{=<int>} all RGB-combinations with a sum $R+G+B <= \text{int}$ are set to
+the color white. 
+
+\subsection{Option for \Lcs{includegraphics}}
+With \Lkeyword{grfOptions} one can define optional arguments for \Lcs{includegraphics}:
 
 \begin{lstlisting}
 \DomainColoring[grfOptions={width=0.49\linewidth},filename=\jobname-tmp2a]{cmath.sin(z)}\hfill
@@ -160,9 +156,14 @@ invers & false & invers colors with $color=|color-255|$\\
 \DomainColoring[grfOptions={width=0.49\linewidth},filename=\jobname-tmp2b]{1/cmath.sin(z)}
 
 
-\clearpage
 \subsection{Higher resolution}
 
+The resolution is more or less the number of pixels for the given domain.
+In later versions of this package it may be possible to have different values
+for the two coordinates. By now the one value for \Lkeyword{resolution} is for
+both axes.
+
+
 \begin{lstlisting}
 \DomainColoring[filename=\jobname-tmp3,resolution=1000,
   grfOptions={width=0.49\linewidth}]{z^3-1}
@@ -193,7 +194,7 @@ The color model (Wikipedia)
 The complex number $z=x+iy$ is converted into its trogonometrical representation $x=r\cdot \cos\phi$ 
 and $y=r\cdot \sin\phi$ with $r=\sqrt{x^2+y^2}$. The values $r$ and $\phi$ are now taken as values
 for the hsv color model with a constant second value for saturation. $\phi$ is used
-for hue. For example: \verb|hsv=phi,1,r|, which gives
+for hue. For example: \verb|hsvrgb=phi,1,r|, which gives
 
 \begin{lstlisting}
 \DomainColoring[filename=\jobname-tmp5a,resolution=1000,
@@ -211,34 +212,40 @@ for hue. For example: \verb|hsv=phi,1,r|, which gives
    grfOptions={width=0.49\linewidth}]{cmath.sin(z)*cmath.sin(0.99*z)} 
 
 %For $r$ and $\phi$ we have to use $r$ and $phi$.
+The optional argument \Lkeyword{hsvrgb} must define three values which can use the arguments
+phi and r in any mathematical combination. It must only be compatible to the Lua math conventions,
+e.g. \texttt{hsvrgb=\{phi+2,0.5,2/r\}}
+
+
+
 
 \subsection{External function definition}
-The already existing file \verb|domaincoloring.functions| collects sone
+The already existing file \LFile{domaincoloring-functions.lua} collects sone
 definitions of complex functions $f(z)$, which can be used from inside \LaTeX\ 
 with the optional argument \Lkeyword{funcName}. In this case the mandatory argument
-of \cs{DomainColoring} has no meaning and can be empty.
+of \Lcs{DomainColoring} has no meaning and can be empty.
 
 \begin{lstlisting}
 \DomainColoring[filename=\jobname-tmp6a,resolution=1000,
    domain={-1.5,1.5,-1.5,1.5}, grfOptions={width=0.49\linewidth},
-   hsvrgb={phi,1,1/r}, funcName=f12]{}%  using predefined function
+   hsvrgb={phi+2*pi,1,1/r}, funcName=f12]{}%  using predefined function
 \hfill
 \DomainColoring[filename=\jobname-tmp6b,resolution=2000,
    domain={-2.3,0.7,-1.5,1.5}, grfOptions={width=0.49\linewidth},
-   hsvrgb={phi,1,1/r},funcName=f13]{}
+   hsvrgb={phi+2*pi,1,1/r},funcName=f13]{}
 \end{lstlisting}
 
 \noindent
 \DomainColoring[filename=\jobname-tmp6a,resolution=1000,
    domain={-1.5,1.5,-1.5,1.5}, grfOptions={width=0.49\linewidth},
-   hsvrgb={phi,1,1/r}, funcName=f12]{}%  using predefined function
+   hsvrgb={phi+2*pi,1,1/r}, funcName=f12]{}%  using predefined function
 \hfill
 \DomainColoring[filename=\jobname-tmp6b,resolution=2000,
    domain={-2.3,0.7,-1.5,1.5}, grfOptions={width=0.49\linewidth},
-   hsvrgb={phi,1,1/r},funcName=f13]{}
+   hsvrgb={phi+2*pi,1,1/r},funcName=f13]{}
 
 
-The currently contents of the function file:
+The contents of the function file of the current version of \LPack{domaincoloring} is::
 
 \lstinputlisting[language={[5.3]Lua},basicstyle=\small\ttfamily]{domaincoloring-functions.lua}
 
@@ -246,4 +253,5 @@ The currently contents of the function file:
 
 \nocite{*}
 \printbibliography
+
 \end{document}
diff --git a/macros/luatex/latex/domaincoloring/doc/titleImg.pdf b/macros/luatex/latex/domaincoloring/doc/titleImg.pdf
new file mode 100644
index 0000000000..e68120b481
--- /dev/null
+++ b/macros/luatex/latex/domaincoloring/doc/titleImg.pdf
diff --git a/macros/luatex/latex/domaincoloring/latex/domaincoloring.sty b/macros/luatex/latex/domaincoloring/latex/domaincoloring.sty
index 8b17cd6a8c..d668d057f0 100644
--- a/macros/luatex/latex/domaincoloring/latex/domaincoloring.sty
+++ b/macros/luatex/latex/domaincoloring/latex/domaincoloring.sty
@@ -1,23 +1,25 @@
-%% $Id: domaincoloring.sty 945 2024-08-21 19:30:48Z herbert $
+%% $Id: domaincoloring.sty 952 2024-08-22 15:40:35Z herbert $
 %% This is file `domaincoloring.sty',
 %%
 %% Copyright (C) 2024-   Herbert Voss
 %%
-%% It may be distributed and/or modified under the
-%% conditions of the LaTeX Project Public License, either version 1.3c
-%% of this license or (at your option) any later version.
+%% This program can be redistributed and/or modified under the terms
+%% of the LaTeX Project Public License Distributed from CTAN archives.
 %% The latest version of this license is in
 %%    http://www.latex-project.org/lppl.txt
-%% and version 1.3c or later is part of all distributions of LaTeX
-%% version 2005/12/01 or later.
 
 \NeedsTeXFormat{LaTeX2e}
-\ProvidesPackage{domaincoloring}
-  [2024/08/21 package for domain coloring of complex values]
+
 \RequirePackage{xkeyval}
 \RequirePackage{graphicx}
 \RequirePackage{shellesc}
 
+\def\fileversion{0.02}
+\def\filedate{2024/08/22}
+\message{`DCol' v\fileversion, \filedate}
+\ProvidesPackage{domaincoloring}
+  [\filedate\ \fileversion\ 0.02 package for domain coloring of complex functions]
+
 \ifnum\ShellEscapeStatus  < 1
     \PackageError{shellesc}{ShellEscape not enabled! Use --shell-escape}%
 \fi
@@ -42,7 +44,7 @@
   filename=\jobname-tmp,     % the external image filename
   resolution=500,            % pixel per (x|y) interval
   domain={-2,2,-2,2},        % x|y domain
-  bgcolor=false,              % RGB value, changes only 0,0,0 -> 255,255,255
+  bgcolor=0,                 % R+G+B value, changes only 0,0,0 -> 255,255,255
   invers=false,              % 0 or 1 vor inverted colors
   grfOptions={scale=0.5},    % LaTeX options for the included image
 }% 
@@ -54,11 +56,11 @@
   \begingroup
   \setDColkeys{#1}%
   \directlua{
-    require("complex-numbers")
+    require("domaincoloring-complex-numbers")
     require ("domaincoloring")
     createData("#2",{\@domaincoloring@domain},{\@domaincoloring@res},
                "\@domaincoloring@funcName","\@domaincoloring@hsvrgb",
-               "\@domaincoloring@bgcolor","\@domaincoloring@invers")}%
+               \@domaincoloring@bgcolor,"\@domaincoloring@invers")}%
   \typeout{Convert domain.eps file to \@domaincoloring@filename.pdf}%
   \ShellEscape{epstopdf domain.eps \@domaincoloring@filename.pdf}%
   %
diff --git a/macros/luatex/latex/domaincoloring/lua/complex-numbers.lua b/macros/luatex/latex/domaincoloring/lua/domaincoloring-complex-numbers.lua
index 7630433984..7630433984 100644
--- a/macros/luatex/latex/domaincoloring/lua/complex-numbers.lua
+++ b/macros/luatex/latex/domaincoloring/lua/domaincoloring-complex-numbers.lua
diff --git a/macros/luatex/latex/domaincoloring/lua/domaincoloring-functions.lua b/macros/luatex/latex/domaincoloring/lua/domaincoloring-functions.lua
index 9bd96de0b2..84cfd65d7c 100644
--- a/macros/luatex/latex/domaincoloring/lua/domaincoloring-functions.lua
+++ b/macros/luatex/latex/domaincoloring/lua/domaincoloring-functions.lua
@@ -55,7 +55,7 @@ function f11(z)
 end
 
 function f12(z)   -- julia
-  local iterateNo = 5
+  local iterateNo = 15
   for n=1,iterateNo do
     z = z^2 + complex(0.25,-0.5)
   end
@@ -63,8 +63,8 @@ function f12(z)   -- julia
 end
 
 function f13(z)   -- mandelbrot
-  local iterateNo = 6
-  c = z
+  local iterateNo = 15
+  local c = z
   z = complex(0,0)
   for n=1,iterateNo do
     z = z^2 + c
diff --git a/macros/luatex/latex/domaincoloring/lua/domaincoloring.lua b/macros/luatex/latex/domaincoloring/lua/domaincoloring.lua
index a040e27424..2b2ae177ea 100644
--- a/macros/luatex/latex/domaincoloring/lua/domaincoloring.lua
+++ b/macros/luatex/latex/domaincoloring/lua/domaincoloring.lua
@@ -1,8 +1,19 @@
--- $Id: domaincoloring.lua 946 2024-08-21 19:32:10Z herbert $
+-- $Id: domaincoloring.lua 952 2024-08-22 15:40:35Z herbert $
+
+-----------------------------------------------------------------------
+--         FILE:  domaincoloring.lua
+--  DESCRIPTION:  create a visual reprensation of a complex function
+-- REQUIREMENTS:  
+--       AUTHOR:  Herbert Voß
+--      LICENSE:  LPPL 1.3
+--
+-----------------------------------------------------------------------
+
+local version = 0.02
 
 kpse.set_program_name("luatex")
 
-require("complex-numbers")
+require("domaincoloring-complex-numbers")
 
 local func = io.open("domaincoloring-functions.lua","r")
 if func~=nil then
@@ -11,12 +22,12 @@ if func~=nil then
 end
 
 local function HSVtoRGB(h, s, v)
-    i = math.floor(h * 6)
-    f = h * 6 - i
-    p = v * (1 - s)
-    q = v * (1 - f * s)
-    t = v * (1 - (1 - f) * s)
-    no = i // 6
+    local i = math.floor(h * 6)
+    local f = h * 6 - i
+    local p = v * (1 - s)
+    local q = v * (1 - f * s)
+    local t = v * (1 - (1 - f) * s)
+    local no = i % 6
     if no == 0 then        return v,t,p
       elseif no == 1 then  return q,v,p
       elseif no == 2 then  return p,v,t
@@ -28,11 +39,14 @@ end
 
 function my_color_scheme(z,hsvrgb)
   r, phi = cmath.polar(z)
+-- phi is in -pi,+pi; change it to [0;2pi]
+  phi = phi+pi
   h_str,s_str,v_str = hsvrgb:match("([^,]+),([^,]+),([^,]+)")
 --  h = load("return "..h_str)()
 --  s = load("return "..s_str)()
 --  v = load("return "..v_str)()
   --h,s,v = loadstring("return"..hsvrgb)
+  -- R,G,B, is [0,...,1]
   R,G,B = HSVtoRGB(load("return "..h_str)(),load("return "..s_str)(),load("return "..v_str)())   --    h,s,v)     -- (phi+3.14,1,r)
   return { math.fmod(math.floor(R*255+0.5),255), 
            math.fmod(math.floor(G*255+0.5),255),
@@ -57,15 +71,15 @@ function write_eps_data(name,data,res)
   outFile = io.open(name,"w+") -- Dateiname
   outFile:write([[
 %!PS-Adobe-3.0 EPSF-3.0
-%%Creator: (ImageMagick)
+%%Creator: (Herbert Voss)
 %%Title: (domain.eps)
-%%CreationDate: (2024-08-21T08:45:55+00:00)
-]])
+%%CreationDate: (]])
+  outFile:write(os.date("%Y-%m-%d-%H.%M.%S")..")\n")
   outFile:write("%%BoundingBox: -0 -0 "..res[1].." "..res[2].."\n")
   outFile:write("%%HiResBoundingBox: 0 0 "..res[1].." "..res[2].."\n")
   outFile:write([[
 %%DocumentData: Clean7Bit
-%%LanguageLevel: 1
+%%LanguageLevel: 2
 %%Pages: 1
 %%EndComments
 %%BeginDefaults
@@ -79,58 +93,7 @@ function write_eps_data(name,data,res)
 } bind def
 /DirectClassImage{
     columns rows 8 [ columns 0 0 rows neg 0 rows ]
-    { DirectClassPacket } false 3 colorimage %}
-} bind def
-/GrayDirectClassPacket {
-  currentfile color_packet readhexstring pop pop
-  color_packet 0 get 0.299 mul
-  color_packet 1 get 0.587 mul add
-  color_packet 2 get 0.114 mul add
-  cvi
-  /gray_packet exch def
-  /number_pixels 1 def
-  0 1 number_pixels 1 sub { pixels exch gray_packet put } for
-  pixels 0 number_pixels getinterval
-} bind def
-/GrayPseudoClassPacket {
-  currentfile byte readhexstring pop 0 get
-  /offset exch 3 mul def
-  /color_packet colormap offset 3 getinterval def
-  color_packet 0 get 0.299 mul
-  color_packet 1 get 0.587 mul add
-  color_packet 2 get 0.114 mul add cvi
-  /gray_packet exch def
-  /number_pixels 1 def
-  0 1 number_pixels 1 sub { pixels exch gray_packet put } for
-  pixels 0 number_pixels getinterval
-} bind def
-/PseudoClassPacket{
-  currentfile byte readhexstring pop 0 get
-  /offset exch 3 mul def
-  /color_packet colormap offset 3 getinterval def
-  /number_pixels 3 def 
-  0 3 number_pixels 1 sub { pixels exch color_packet putinterval } for
-  pixels 0 number_pixels getinterval
-} bind def
-/PseudoClassImage{
-  currentfile buffer readline pop
-  token pop /class exch def pop
-  class 0 gt {
-    currentfile buffer readline pop
-    token pop /depth exch def pop
-    /grays columns 8 add depth sub depth mul 8 idiv string def
-    columns rows depth
-    [ columns 0 0 rows neg 0 rows ]
-    { currentfile grays readhexstring pop } image
-  }{
-    currentfile buffer readline pop
-    token pop /colors exch def pop
-    /colors colors 3 mul def
-    /colormap colors string def
-    currentfile colormap readhexstring pop pop
-    columns rows 8 [ columns 0 0 rows neg 0 rows ]
-        { PseudoClassPacket } false 3 colorimage
-  } ifelse
+    { DirectClassPacket } false 3 colorimage 
 } bind def
 /DisplayImage {
   gsave
@@ -155,7 +118,7 @@ function write_eps_data(name,data,res)
   token pop /class exch def pop
   currentfile buffer readline pop
   token pop /compression exch def pop
-  class 0 gt { PseudoClassImage } { DirectClassImage } ifelse
+  DirectClassImage
   grestore
 } bind def
 %%EndProlog
@@ -196,7 +159,7 @@ DisplayImage
     end
   end
   outFile:write("\n")        -- neue Zeile 
-  outFile:write([[end
+  outFile:write([[end % of userdict
 %%PageTrailer
 %%Trailer
 %%EOF
@@ -206,7 +169,7 @@ DisplayImage
 end
 
 function write_data(name,data,res)  -- only valid for writing ppm files
-  print("Lua: writing data file "..name.." ...")
+  print("\nLua: writing data file "..name.." ...")
 --  print(data)
   outFile = io.open(name,"w+") -- Dateiname
   outFile:write("P3 ")                -- Grafictype R G B
@@ -254,15 +217,16 @@ function plot(fString, domain, res, funcName, hsvrgb, bgColor, invers)
         fz = load("return "..fString)() -- for example: cmath.cos(z)/cmath.sin(z^4-1)
       end        
       color = my_color_scheme(fz,hsvrgb)
-      if bgColor == "true" then
-        if color[1] + color[2] + color[3] == 0 then
-          color = { 255, 255, 255 }
-        end
-      elseif invers == "true" then
+      if invers == "true" then
         for c=1,#color do
           color[c] = math.abs(color[c]-255)
         end
       end
+      if bgColor > 0 then
+        if color[1] + color[2] + color[3] <= bgColor then
+          color = { 255, 255, 255 }
+        end
+      end
 --      print(x,y,color[1],color[2],color[3])
       img[row][col] = color
     end