spdep (version 1.2-4)

diffnb: Differences between neighbours lists

Description

The function finds differences between lists of neighbours, returning a nb neighbour list of those found

Usage

diffnb(x, y, verbose=NULL)

Value

A neighbours list with class nb

Arguments

x

an object of class nb

y

an object of class nb

verbose

default NULL, use global option value; report regions ids taken from object attribute "region.id" with differences

Author

Roger Bivand

Examples

columbus <- st_read(system.file("shapes/columbus.shp", package="spData")[1], quiet=TRUE)
coords <- st_centroid(st_geometry(columbus), of_largest_polygon=TRUE)
rn <- row.names(columbus)
knn1 <- knearneigh(coords, 1)
knn2 <- knearneigh(coords, 2)
nb1 <- knn2nb(knn1, row.names=rn)
nb2 <- knn2nb(knn2, row.names=rn)
diffs <- diffnb(nb2, nb1)
opar <- par(no.readonly=TRUE)
plot(st_geometry(columbus), border="grey", reset=FALSE,
 main="Plot of first (black) and second (red)\nnearest neighbours")
plot(nb1, coords, add=TRUE)
plot(diffs, coords, add=TRUE, col="red", lty=2)
par(opar)