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
rad.simple.cov.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
"Rad.simple.cov" <- function(x1, x2, p = 1, with.log = TRUE,
with.constant = TRUE, C = NA, marginal = FALSE) {
if (marginal) {
return(rep(1, nrow(x1)))
}
if (!is.matrix(x1))
x1 <- as.matrix(x1)
if (!is.matrix(x2))
x2 <- as.matrix(x2)
d <- ncol(x1)
n1 <- nrow(x1)
n2 <- nrow(x2)
m <- (d + p)/2
temp <- rdist(x1, x2)
if (with.constant) {
Amd <- radbas.constant(m, d)
}
else {
Amd <- 1
}
if ((d%%2 == 0) & (with.log)) {
temp <- Amd * ifelse(temp < 1e-10, 0, temp^(p/2) * log(temp))
}
else {
temp <- Amd * temp^(p)
}
#
#
if (is.na(C[1])) {
return(temp)
}
else {
return(temp %*% C)
}
}