Nothing
# Copyright 2001-24 by Roger Bivand
#
droplinks <- function(nb, drop, sym=TRUE) {
# class to inherits Jari Oksanen 080603
if (!inherits(nb, "nb")) stop("not a neighbours list")
n <- length(nb)
cnb <- card(nb)
if (n < 1) stop("non-positive length of nb")
if (is.logical(drop)) {
if(length(drop) != n) stop("Argument lengths differ")
idrop <- which(drop == TRUE)
} else if(is.character(drop)) {
row.names <- as.character(attr(nb, "region.id"))
idrop <- match(drop, row.names)
if(any(is.na(idrop))) stop("Region to drop not found")
} else {
idrop <- match(drop, 1:n)
if(any(is.na(idrop))) stop("Region to drop not found")
}
if((attr(nb, "sym") == FALSE) && (sym == TRUE)) {
warning("setting sym to FALSE")
sym <- FALSE
}
for (i in idrop) {
if (sym && cnb[i] > 0) {
for (j in nb[[i]])
nb[[j]] <- nb[[j]][nb[[j]] != i]
}
nb[[i]] <- 0L
}
nb <- sym.attr.nb(nb)
cans <- card(nb)
if (get.NoNeighbourOption()) {
if (any(cans == 0L)) warning("some observations have no neighbours")
}
NE <- n + sum(cans)
if (get.SubgraphOption() && get.SubgraphCeiling() > NE) {
ncomp <- n.comp.nb(nb)
attr(nb, "ncomp") <- ncomp
if (ncomp$nc > 1) warning("neighbour object has ", ncomp$nc, " sub-graphs")
}
nb
}
addlinks1 <- function(nb, from, to, sym=TRUE) {
if (!inherits(nb, "nb")) stop("not a neighbours list")
stopifnot(length(from) == 1L)
n <- length(nb)
cnb <- card(nb)
if (n < 1) stop("non-positive length of nb")
row.names <- as.character(attr(nb, "region.id"))
if (is.character(from)) {
ifrom <- match(from, row.names)
if(any(is.na(ifrom))) stop("from-region not found")
} else {
ifrom <- match(from, 1:n)
if (any(is.na(ifrom))) stop("from-region not found")
}
if (is.character(to)) {
ito <- match(to, row.names)
if (any(is.na(ito))) stop("to-region not found")
} else {
ito <- match(to, 1:n)
if(any(is.na(ito))) stop("to-region drop not found")
}
if ((attr(nb, "sym") == FALSE) && (sym == TRUE)) {
warning("setting sym to FALSE")
sym <- FALSE
}
orig <- nb[[ifrom]]
orig <- orig[orig > 0L]
nb[[ifrom]] <- as.integer(sort(unique(c(orig, ito))))
if (sym) {
for (i in ito) {
orig <- nb[[i]]
orig <- orig[orig > 0L]
nb[[i]] <- as.integer(sort(unique(c(orig, ifrom))))
}
}
nb <- sym.attr.nb(nb)
NE <- n + sum(card(nb))
if (get.SubgraphOption() && get.SubgraphCeiling() > NE) {
ncomp <- n.comp.nb(nb)
attr(nb, "ncomp") <- ncomp
if (ncomp$nc > 1) warning("neighbour object has ", ncomp$nc, " sub-graphs")
}
nb
}
Any scripts or data that you put into this service are public.
Add the following code to your website.
For more information on customizing the embed code, read Embedding Snippets.