\documentclass{article} \usepackage[T1]{fontenc} \usepackage[latin1]{inputenc} \usepackage{pstricks,pstricks-add} \usepackage{lmodern} \parindent=0pt \pagestyle{empty} \begin{document} \psset{unit=5} \psset{method=rk4, algebraic=true, whichabs=0, whichord=1, plotpoints=500,linewidth=1pt} \begin{pspicture}(-1.2,-0.2)(1.2,0.2) \psgrid[subgriddiv=5,subgridcolor=black!10,gridlabels=7pt](-1.2,-0.2)(1.2,0.2) \psplotDiffEqn[linecolor=red]{0}{12}{0 0 0 0}{% y[2]|y[3]|6.283185*y[3]|4*cos(0.6283185*x)-6.283185*y[2]} \end{pspicture} %\begin{verbatim} % \psplotDiffEqn[linecolor=red]{0}{12}{0 0 0 0}{% % y[2]|y[3]|6.283185*y[3]|4*cos(0.6283185*x)-6.283185*y[2]} %\end{verbatim} \bigskip \begin{pspicture}(-1.2,-0.2)(1.2,0.2) \psgrid[subgriddiv=5,subgridcolor=black!10,gridlabels=7pt](-1.2,-0.2)(1.2,0.2) \parametricplot[plotpoints=500,linecolor=blue]{0}{12}{% 4/(6.283185^2-(0.6283185)^2)*(sin(0.6283185*t)/0.1-sin(6.283185*t))|% 4/(6.283185^2-(0.6283185)^2)*(cos(0.6283185*t)-cos(6.283185*t))} \end{pspicture} %\begin{verbatim} % \parametricplot[plotpoints=500,linecolor=blue]{0}{12}{% % 4/(6.283185^2-(0.6283185)^2)*(sin(0.6283185*t)/0.1-sin(6.283185*t))|% % 4/(6.283185^2-(0.6283185)^2)*(cos(0.6283185*t)-cos(6.283185*t))} %\end{verbatim} \end{document}