\begin{Schunk}
\begin{Sinput}
 plot(x, y, type="n", main="pspline with CV selection of smooth parameter")
 points(x, y, col=gray(.70))
 lines(psp10$x, psp10$ysmth, lty=4, lwd=0.6)
 lines(psp15$x, psp15$ysmth, lty=3)
 lines(psp26$x, psp26$ysmth, lty=2)
 lines(psp35$x, psp35$ysmth, lty=1)
 legend("top", legend=c("spar=0","spar=0.8","df=10","CV"),lty=4:1)
\end{Sinput}
\end{Schunk}
