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
Krig.discretize.r
"Krig.discretize" <-
function(x, m = 64, n = 64, xg = NULL, yg = NULL, grid = NULL, expand = c(
1, 1))
{
#
# set up discretized grid based on x
#
out <- list()
if(!is.null(grid)) {
xg <- grid$x
yg <- grid$y
m <- length(xg)
n <- length(yg)
}
if(length(expand) == 1)
expand <- rep(expand, 2)
if(is.null(xg)) {
xr <- range(x[, 1])
deltemp <- (xr[2] - xr[1]) * (expand[1] - 1) * 0.5
xg <- seq(xr[1] - deltemp, xr[2] + deltemp, , m)
}
else {
xr <- range(xg)
}
if(is.null(yg)) {
yr <- range(x[, 2])
deltemp <- (yr[2] - yr[1]) * (expand[2] - 1) * 0.5
yg <- seq(yr[1] - deltemp, yr[2] + deltemp, , n)
}
else {
yr <- range(yg)
}
del <- 1e-08 + (0.5 * (max(xr[2]) - min(xr[1])))/(m - 1)
xcut <- seq(xr[1] - del, xr[2] + del, , (m + 1))
del <- 1e-08 + (0.5 * (max(yr[2]) - min(yr[1])))/(n - 1)
ycut <- seq(yr[1] - del, yr[2] + del, , (n + 1))
out$m <- length(xg)
out$n <- length(yg)
out$index <- cbind(cut(x[, 1], xcut), cut(x[, 2], ycut))
# out$cut.grid <- list(x = xcut, y = ycut) #
#
out$grid <- list(x = xg, y = yg)
out$loc <- cbind(xg[out$index[, 1]], yg[out$index[, 2]])
out
}