how to resize easily a pstricks picture?
Changing the units (unit itself and linewidth) does resize the image:
\documentclass{article}
\usepackage[pdf]{pstricks}
\newpsobject{pslineA}{psline}{linewidth=6\pslinewidth, linecolor=green}
\newpsobject{pslineB}{psline}{linewidth=10\pslinewidth, linecolor=red}
\begin{document}
\begin{pspicture}(5,5)
\psline(0,1)(5,1)
\psline[linewidth=1mm](0,2)(5,2)
\pslineA(0,3)(5,3)
\pslineB(0,4)(5,4)
\end{pspicture}\\[2cm]
\psset{unit =1.5cm, linewidth=1.5\pslinewidth}
\begin{pspicture}(5,5)
\psline(0,1)(5,1)
\psline[linewidth=1mm](0,2)(5,2)
\pslineA(0,3)(5,3)
\pslineB(0,4)(5,4)
\end{pspicture}
\end{document}
setting the linewidth as a multiple of \pslinewidth
sets it as an absolute value, the reason why the \psset{unit=1.5}
doesn't change the setting. Compare it with
\newpsobject{pslineA}{psline}{linewidth=0.05, linecolor=green}
\newpsobject{pslineB}{psline}{linewidth=0.2, linecolor=red}
which is a relative linewidth setting which refers to the current units, e.g. 1cm. Then you can say \psset{unit=..}
or
\psscalebox{<value>}{%
\begin{pspicture}(..)(..)
...
\end{pspicture}}
for rescaling the pspicture
environment.