https://github.com/cran/fields
Tip revision: 8eab500c3dad2103092ff68706417414fe53e16b authored by Doug Nychka on 22 September 2009, 20:23:49 UTC
version 6.01
version 6.01
Tip revision: 8eab500
fields.derivative.poly.R
# fields, Tools for spatial data
# Copyright 2004-2007, Institute for Mathematics Applied Geosciences
# University Corporation for Atmospheric Research
# Licensed under the GPL -- www.gpl.org/licenses/gpl.html
fields.derivative.poly <- function(x, m, dcoef) {
# dimension of x locations
# goal is find partial derivative matrix
d <- ncol(x)
out <- fields.mkpoly(rbind(x[1, ]), m)
ptab <- attr(out, "ptab")
if (nrow(ptab) != length(dcoef)) {
stop(" rows of ptab not equal to length of dcoef")
}
hold <- matrix(NA, ncol = d, nrow = nrow(x))
for (k in 1:d) {
nonzero <- ptab[, k] != 0
ptemp <- matrix(ptab[nonzero, ], ncol = d)
dtemp <- dcoef[nonzero]
dtemp <- dtemp * ptemp[, k]
ptemp[, k] <- ptemp[, k] - 1
hold[, k] <- fields.evlpoly2(x, dtemp, ptemp)
}
return(hold)
}