https://github.com/cran/fields
Tip revision: c71fb7f6ffa323303affebf0e35a0070faa9c24d authored by Doug Nychka on 10 May 2004, 00:00:00 UTC
version 1.7.2
version 1.7.2
Tip revision: c71fb7f
exp.cov.r
"exp.cov" <-
function (x1, x2, theta = rep(1, ncol(x1)), p = 1, C = NA)
{
if (!is.matrix(x1))
x1 <- as.matrix(x1)
if (missing(x2))
x2 <- x1
if (!is.matrix(x2))
x2 <- as.matrix(x2)
if (length(theta) == 1)
theta <- rep(theta, ncol(x1))
d <- ncol(x1)
n1 <- nrow(x1)
n2 <- nrow(x2)
x1 <- t(t(x1)/theta)
x2 <- t(t(x2)/theta)
par <- p
if (is.na(C[1])) {
exp(-rdist(x1, x2)^p)
}
else {
.Fortran("multeb", nd = as.integer(d), x1 = as.double(x1),
n1 = as.integer(n1), x2 = as.double(x2), n2 = as.integer(n2),
par = as.double(par), c = as.double(C), h = as.double(rep(0,
n1)), work = as.double(rep(0, n2)),PACKAGE="fields")$h
}
}