smooth.bibasis: Smooth a discrete surface over a rectangular lattice
Description
Estimate a smoothing function f(s, t) over a rectangular lattice
Usage
smooth.bibasis(sarg, targ, y, fdPars, fdPart, fdnames=NULL, returnMatrix=FALSE)
Arguments
sarg, targ
vectors of argument values for the first and second dimensions,
respectively, of the surface function.
y
an array containing surface values measured with noise
fdPars, fdPart
functional parameter objects for sarg and targ,
respectively
fdnames
a list of length 3 containing character vectors of names for
sarg, targ, and the surface function f(s, t).
returnMatrix
logical: If TRUE, a two-dimensional is returned using a
special class from the Matrix package.
Value
a list with the following components:
fdobja functional data object containing a smooth of the data.
dfa degrees of freedom measure of the smooth
gcvthe value of the generalized cross-validation or GCV criterion. If
the function is univariate, GCV is a vector containing the error
sum of squares for each function, and if the function is
multivariate, GCV is a NVAR by NCURVES matrix.
coefthe coefficient matrix for the basis function expansion of
the smoothing function
SSEthe error sums of squares. SSE is a vector or a matrix of the same
size as GCV.
penmatthe penalty matrix.
y2cMapthe matrix mapping the data to the coefficients.