[pstricks] Drawing "real" circle-like stain

[Herbert Voss]

Christophe Jorssen wrote:

> 
> I'm looking for some code that could fake a stain. It's for drawing a "real"
> chromatography diagram.
> 
> I had a look at
> 
> http://www.complex.unifi.it/twiki/bin/view/Software/PSTDisegniManuali
> 
> but I'd like to have a command like
> 
> \pstStain that would take the same argument as \pscircle.

the options are selfexplanatory

Herbert


\documentclass[a4paper,10pt]{article}
\usepackage{pstricks}
\usepackage{pst-xkey}

\makeatletter
\define at key[psset]{}{stain}{\def\psk at stain{#1}}
\define at key[psset]{}{step}{\def\psk at step{#1}}
\define at key[psset]{}{stRadius}{\def\psk at stRadius{#1}}
\psset{stain=3,step=0.25,stRadius=0.5}% step in degrees, the other in pt
%
\def\psCStain{\pst at object{psCStain}}
\def\psCStain at i(#1)#2{{%
   \begin at ClosedObj
   \use at par%
%  \pscircle(#1)#2
   \pst at getcoor{#1}\pst at tempa%
   \pssetlength\pst at dimc{#2}%
   \def\pst at linetype{4}%
   \addto at pscode{%
     rrand srand
     /getRandInt { rand 2147483647 div 2 mul 1 sub \psk at stain\space mul 
} def
%    gsave
     \pst at tempa\space translate pstack
     /radius \pst at number\pst at dimc \psk at dimen CLW mul sub def
     0 \psk at step\space 360 {
       /angle exch def
       radius getRandInt add dup angle cos mul exch angle sin mul
       \psk at stRadius\space 0 360 arc fill
     } for
     stroke
%    grestore
   }%
   \end at ClosedObj
}}
\makeatother
\begin{document}

\begin{pspicture}(5,5)\psgrid[griddots=5,subgriddiv=0]
\psCStain(2.5,2.5){2.5}
\end{pspicture}



-- 
http://TeXnik.de/
http://PSTricks.de/
ftp://ftp.dante.de/tex-archive/info/math/voss/Voss-Mathmode.pdf
http://www.dante.de/faq/de-tex-faq/
http://www.tex.ac.uk/cgi-bin/texfaq2html?introduction=yes