https://github.com/cran/fda
Tip revision: aac3e3f7207f4732067b6e1d1b735f5d7855664f authored by J. O. Ramsay on 06 July 2007, 00:00:00 UTC
version 1.2.4
version 1.2.4
Tip revision: aac3e3f
eval.basis.R
eval.basis <- function(evalarg, basisobj, Lfdobj=0) {
# Computes the basis matrix evaluated at arguments in EVALARG associated
# with basis.fd object BASISOBJ. The basis matrix contains the values
# at argument value vector EVALARG of applying the nonhomogeneous
# linear differential operator LFD to the basis functions. By default
# LFD is 0, and the basis functions are simply evaluated at argument
# values in EVALARG.
#
# If LFD is a functional data object with m + 1 functions c_1, ... c_{m+1}, then it
# is assumed to define the order m HOMOGENEOUS linear differential operator
# Lx(t) = c_1(t) + c_2(t)x(t) + c_3(t)Dx(t) + ... + c_{m+1}D^{m-1}x(t) + D^m x(t).
#
# If the basis type is either polygonal or constant, LFD is ignored.
#
# Arguments:
# EVALARG ... Either a vector of values at which all functions are to evaluated,
# or a matrix of values, with number of columns corresponding to
# number of functions in argument FD. If the number of evaluation
# values varies from curve to curve, pad out unwanted positions in
# each column with NA. The number of rows is equal to the maximum
# of number of evaluation points.
# BASISOBJ ... A basis object
# LFDOBJ ... A linear differential operator object
# applied to the basis functions before they are to be evaluated.
#
# Note that the first two arguments may be interchanged.
#
# Last modified 26 October 2005
# Exchange the first two arguments if the first is an BASIS.FD object
# and the second numeric
if (is.numeric(basisobj) && inherits(evalarg, "basisfd")) {
temp <- basisobj
basisobj <- evalarg
evalarg <- temp
}
# check EVALARG
if (!(is.numeric(evalarg))) stop("Argument EVALARG is not numeric.")
if (!is.vector(evalarg)) stop("Argument EVALARG is not a vector.")
# check basisobj
if (!(inherits(basisobj, "basisfd"))) stop(
"Second argument is not a basis object.")
# check LFDOBJ
Lfdobj <- int2Lfd(Lfdobj)
# determine the highest order of derivative NDERIV required
nderiv <- Lfdobj$nderiv
# get weight coefficient functions
bwtlist <- Lfdobj$bwtlist
# get highest order of basis matrix
evalarray <- getbasismatrix(evalarg, basisobj, nderiv)
nbasis <- dim(evalarray)[2]
oneb <- matrix(1,1,nbasis)
# Compute the weighted combination of derivatives is
# evaluated here if the operator is not defined by an
# integer and the order of derivative is positive.
if (nderiv > 0) {
nonintwrd <- FALSE
for (j in 1:nderiv) {
bfd <- bwtlist[[j]]
bbasis <- bfd$basis
if (bbasis$type != "constant" || bfd$coefs != 0) nonintwrd <- TRUE
}
if (nonintwrd) {
for (j in 1:nderiv) {
bfd <- bwtlist[[j]]
if (!all(c(bfd$coefs) == 0.0)) {
wjarray <- eval.fd(evalarg, bfd)
Dbasismat <- getbasismatrix(evalarg, basisobj, j-1)
evalarray <- evalarray + (wjarray %*% oneb)*Dbasismat
}
}
}
}
return(evalarray)
}