[pstricks] patch : autoscale y axis for psgraph

[Martin Chicoine]

>Martin Chicoine wrote:
>> I changed lines 2047 and 2072 of the \psgraph definition in pstricks.tex 
>> to :
>> 
>> \ifdim#6=0cm\pst at dima=\pst at tempA\pst at dimo\else\pst at dima=#6\fi\relax
>> and
>> \ifdim#8=0cm\pst at dima=\pst at tempA\pst at dimo\else\pst at dima=#8\fi\relax
>> , respectively.
>> 
>> This allows to autoscale yLength (so that the scale of the x- and y-axis 
>> are the same) if the user enters yLength=0cm.
>
>Please give a full working minimal example, where
>this maybe useful.
>
>Thanks
>Herbert

Here is an example where you don't have to calculate yLength in order to
have the same x- and y-scale. It is calculated automatically by setting
yLength to 0cm. 

\documentclass{article}
\usepackage{pstricks-add-2}
\begin{document}
\psset{algebraic,subgriddiv=0}
  \centering
  \begin{psgraph}(0,0)(-4.5,-1.5)(3.5,3.5){.5\textwidth}{0cm}
    \psplot{-2}{2}{x^2}
  \end{psgraph}
\end{document}

Martin.