cpplot {locfit} | R Documentation |
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.
cpplot(..., alpha, sig2)
... |
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 provided as a vector, it will be converted to a one-column
matrix, thus interpreting each component as a nearest neighbor
smoothing parameter. |
sig2 |
Residual variance. If not specified, the residual variance is computed using the fitted model with the fewest residual degrees of freedom. |
An object with class "gcvplot"
, containing the smoothing
parameters and CP scores. The actual plot is produced using
plot.gcvplot
.
locfit
,
locfit.raw
,
gcv
,
aic
,
plot.gcvplot
data(ethanol) plot(cpplot(NOx~E,data=ethanol,alpha=seq(0.2,1.0,by=0.05)))