\documentclass{article}

\usepackage{pstricks-add}

\begin{document}

\psset{xunit=0.5cm,yunit=0.5cm,linecolor=red}
\newpsstyle{graphstyle}{linecolor=green}
\newpsstyle{plotstyle}{linewidth=3pt}

\begin{pspicture}(-10,-5)(10,5)
  \psplot{-10}{10}{x 180 mul 3.1416 div sin}
  \psaxes(0,0)(-10,-5)(10,5)
\end{pspicture}

\vspace{1cm}

\begin{pspicture}(-10,-5)(10,5)
  \psplot[algebraic]{-10}{10}{sin(x)}
  \psaxes(0,0)(-10,-5)(10,5)
\end{pspicture}

\psset{algebraic}

\begin{psgraph}[ticksize=0,labels=none](0,0)(-10,-5)(10,5){.5\textwidth}{!}
  \psplot[linecolor=blue]{-10}{10}{cos(x)}
\end{psgraph}

\end{document}
