subset.nb {spdep} | R Documentation |
The function subsets a neighbors list, retaining objects for which the subset argument vector is TRUE.
subset.nb(x, subset, ...)
x |
an object of class nb |
subset |
logical expression |
... |
generic function pass-through |
The function returns an object of class nb
with a list of
integer vectors containing neighbour region number ids (compacted to
run from 1:number of regions in subset).
Roger Bivand Roger.Bivand@nhh.no
data(columbus) plot(col.gal.nb, coords) to.be.dropped <- c(31, 34, 36, 39, 42, 46) text(coords[to.be.dropped,1], coords[to.be.dropped,2], labels=to.be.dropped, pos=2, offset=0.3) sub.col.gal.nb <- subset(col.gal.nb, !(1:length(col.gal.nb) %in% to.be.dropped)) plot(sub.col.gal.nb, coords[-to.be.dropped,], col="red", add=TRUE) which(!(attr(col.gal.nb, "region.id") %in% attr(sub.col.gal.nb, "region.id")))