[pstricks] postscript calculation within pstricks arguments

[Herbert Voss]

Am 05.05.2010 22:21, schrieb Mathias Legrand:

> but I would like to perform postscript calculations as follows (for
> instance) :
> 
> \mypsframe{\i}{\I\space \i add 10 mul}
> 
> but it does not work. Is there a systematic method for such requests?

use the \numexpr macro from etex.
However *10 cannot work, because xcolor allows only black!100

\documentclass{article}
\usepackage{pstricks-add,etex}
\usepackage{multido}

\begin{document}

\thispagestyle{empty}

\def\mypsframe#1#2{%
 \psframe[linearc=#1 pt,cornersize=absolute,%
  fillstyle=solid,fillcolor=black!#2](0,0)(1,1)}

\psframe[fillstyle=solid,fillcolor=red!30](-8,-30)(21,30)

\multido{\i=0+1}{22}{%
  \multido{\I=0+1}{30}{%
    \rput[cc]{!4 \I\space mul 4 \i\space mul add}(!1 dup \i\space mul
5.2 sub exch \I\space sub 2.7 add){%
  \mypsframe{\i}{\number\numexpr(\I+\i)*2}}
   }%
}%

\end{document}

Herbert