
| ksmooth | Kernel Regression Smoother |
| plot.ppr | Plot Ridge Functions for Projection Pursuit Regression Fit |
| ppr | Projection Pursuit Regression |
| predict.smooth.spline | Predict from Smoothing Spline Fit |
| smooth.spline | Fit a Smoothing Spline |
| supsmu | Friedmans's SuperSmoother |