This function is used to extract a coefficient from a fitted `pfr` model, in
particular smooth functions resulting from including functional terms specified
af, etc. It can also be used to extract smooths
# S3 method for pfr coefficients( object, select = 1, coords = NULL, n = NULL, se = ifelse(length(object$smooth) & select, TRUE, FALSE), seWithMean = FALSE, useVc = TRUE, Qtransform = FALSE, ... )
# S3 method for pfr coef( object, select = 1, coords = NULL, n = NULL, se = ifelse(length(object$smooth) & select, TRUE, FALSE), seWithMean = FALSE, useVc = TRUE, Qtransform = FALSE, ... )
return object from
integer indicating the index of the desired smooth term
object$smooth. Enter 0 to request the raw coefficients
object$coefficients) and standard errors (if
named list indicating the desired coordinates where the
coefficient function is to be evaluated. Names must match the argument names
to generate equally-spaced coordinates.
integer vector indicating the number of equally spaced coordinates
for each argument. If length 1, the same number is used for each argument.
Otherwise, the length must match
TRUE, returns pointwise standard error estimates. Defaults
FALSE if raw coefficients are being returned; otherwise
TRUE the standard errors include uncertainty about
the overall mean; if
FALSE, they relate purely to the centered
smooth itself. Marra and Wood (2012) suggests that
TRUE results in
better coverage performance for GAMs.
TRUE, standard errors are calculated using a covariance
matrix that has been corrected for smoothing parameter uncertainty. This
matrix will only be available under ML or REML smoothing.
For additive functional terms,
TRUE indicates the
coefficient should be extracted on the quantile-transformed scale, whereas
FALSE indicates the scale of the original data. Note this is
different from the
Qtransform arguemnt of
af, which specifies
the scale on which the term is fit.
these arguments are ignored
a data frame containing the evaluation points,
coefficient function values and optionally the SE's for the term indicated
Marra, G and S.N. Wood (2012) Coverage Properties of Confidence Intervals for Generalized Additive Model Components. Scandinavian Journal of Statistics.