\documentclass{scrartcl}
\usepackage{color}
\usepackage{multicol}
\usepackage[final]{graphicx}
\usepackage{pst-plot,pstricks}
	\input{pstplot-logarithmic-axes}
\begin{document}
	\psset{xunit=2cm,yunit=4cm}
	\begin{pspicture}(-0.5,-0.6)(5,0.6)
		\psgrid[xunit=1,yunit=1,subgriddiv=0,griddots=5,gridlabels=0](0,-0.5)(4,0.5)
		\psaxes[Dx=1,Dy=0.5]{->}(0,0)(-0.2,-0.6)(4.5,0.6)
		\psplot[plotstyle=curve]{0}{4}{x 4 div 360 mul cos -0.5 mul}
		\rput[l](4.5,0){$\frac{\omega\tau}{\frac{\pi}{2}}$}
	\end{pspicture}
\end{document}
