Learn R Programming

locfit (version 1.5-6)

cpplot: Compute a Cp plot.

Description

The cpplot function loops through calls to the cp function (and hence to link{locfit}), using a different smoothing parameter for each call. The returned structure contains the Cp statistic for each fit, and can be used to produce an AIC plot.

Usage

cpplot(..., alpha, sig2)

Arguments

...
arguments to the cp, locfit functions.
alpha
Matrix of smoothing parameters. The cpplot function loops through calls to cp, using each row of alpha as the smoothing parameter in turn. If alpha is provid
sig2
Residual variance. If not specified, the residual variance is computed using the fitted model with the fewest residual degrees of freedom.

Value

  • An object with class "gcvplot", containing the smoothing parameters and CP scores. The actual plot is produced using plot.gcvplot.

See Also

locfit, locfit.raw, gcv, aic, plot.gcvplot

Examples

Run this code
data(ethanol)
plot(cpplot(NOx~E,data=ethanol,alpha=seq(0.2,1.0,by=0.05)))

Run the code above in your browser using DataLab