\documentclass{article}

\usepackage{pstricks-add}
\usepackage[active,tightpage]{preview}
\PreviewEnvironment{pspicture}
\setlength\PreviewBorder{16pt}
\begin{document}

\begin{psgraph}(0,0)(2,2){2cm}{2cm}

\psplot[linecolor=red]{0}{2}{x}

\end{psgraph}

\end{document}