[pstricks] ifelse in \psplot

[Goebel, Juergen, OPE26]

Hi,

please have a look at the following PSTricks-code (one
of my first efforts using postscript).


\documentclass{scrartcl}
\usepackage{pstricks}
\usepackage{pst-plot}
\begin{document}
\psset{unit=1mm}
\begin{pspicture}(0,-18)(24,18)
  \psline(0,0)(24,0)
  \psplot{0}{24}{%
     x 15 mul sin 3 mul
     x 15 mul 3 mul sin
     sub
     4.5 mul
  }
\end{pspicture}
\end{document}


What I'd like to have (but cannot achieveso far) is to eliminate
the negative branch of the graph by using the ifelse-command
from postscript. Is it at all allowed in \psplot? Or do I have
to use \pstVerb? And if so, how?

TIA,

Jürgen
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://tug.org/pipermail/pstricks/attachments/20041011/7f59e4c9/attachment.html