\pageinsert \vbox to \vsize{ \centerline{\psfig{file=figures/allsmooths.p,width=\hsize}} \figurecaption{\allsmooths}{A variety of smooths applied to the scatterplot of \name{log(C-peptide)} versus \name{age}. In each case the smoothing parameter was chosen so that degrees of freedom in the fit is about five. The linear fit of course has only two degrees of freedom. The parametric bin and quartic polynomial fits have five parameters. The (cubic) regression spline has one interior knot at the median and hence five parameters. The natural cubic regression spline has three interior knots and two endpoint constraints, which also results in five parameters. For the other smooths, the smoothing parameter $\lambda$ was chosen such that $\df\approx 5$, where \df\ is a measure of the approximate degrees of freedom (a concept introduced in Chapter~3).}* \vfill } \endinsert