https://github.com/cran/fields
Tip revision: 04279c16ce718b82025aae97f6fcd30ba3a8b1c5 authored by Doug Nychka on 05 September 2011, 20:18:33 UTC
version 6.6
version 6.6
Tip revision: 04279c1
Wtransform.image.cov.R
# fields, Tools for spatial data
# Copyright 2004-2011, Institute for Mathematics Applied Geosciences
# University Corporation for Atmospheric Research
# Licensed under the GPL -- www.gpl.org/licenses/gpl.html
"Wtransform.image.cov" <- function(ind1, ind2 = ind1,
Y, cov.obj) {
#
# define useful local function that does the H multiplcation
# taking advantage of the block diagonal form
#
Mult.H <- function(u, H.obj) {
IND <- H.obj$ind0
u[IND] <- H.obj$H0 %*% c(u[IND])
u * H.obj$H1
}
IND <- cov.obj$ind0
CUT <- cov.obj$cut.min
if (missing(ind1)) {
# do multiplcation for full matrix.
if ((nrow(Y) != cov.obj$m) | (ncol(Y) != cov.obj$m)) {
stop("bad dimensions for Y")
}
hold <- Wtransform.image(Y, cut.min = CUT, inv = TRUE,
transpose = TRUE)
hold <- Mult.H(hold, cov.obj)
hold <- Mult.H(hold, cov.obj)
return(Wtransform.image(hold, cut.min = CUT, inv = TRUE))
}
else {
# multiplication for subset of indices
temp <- matrix(0, nrow = cov.obj$m, ncol = cov.obj$n)
temp[ind2] <- Y
#
hold <- Wtransform.image(temp, cut.min = CUT, inv = TRUE,
transpose = TRUE)
hold <- Mult.H(hold, cov.obj)
hold <- Mult.H(hold, cov.obj)
return(Wtransform.image(hold, cut.min = CUT, inv = TRUE)[ind1])
}
}