gcvplot {locfit}R Documentation

Compute a generalized cross-validation plot.

Usage

gcvplot(..., alpha, df=2)

Arguments

... arguments to the gcv, locfit functions.
alpha Matrix of smoothing parameters. The gcvplot function loops through calls to gcv, using each row of alpha as the smoothing parameter in turn. If alpha is provided as a vector, it will be converted to a one-column matrix, thus interpreting each component as a nearest neighbor smoothing parameter.
df Degrees of freedom to use as the x-axis. 2=trace(L), 3=trace(L'L).

Value

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

See Also

locfit, locfit.raw, gcv plot.gcvplot

Examples

data(ethanol)
plot(gcvplot(NOx~E,data=ethanol,alpha=seq(0.2,1.0,by=0.05)))