diffnb {spdep} | R Documentation |
The function finds differences between lists of neighbours, returning a nb
neighbour list of those found
diffnb(x, y, verbose=NULL)
x |
an object of class |
y |
an object of class |
verbose |
default NULL, use global option value; report regions ids taken from object attribute "region.id" with differences |
A neighbours list with class nb
Roger Bivand Roger.Bivand@nhh.no
example(columbus) coords <- coordinates(columbus) rn <- sapply(slot(columbus, "polygons"), function(x) slot(x, "ID")) knn1 <- knearneigh(coords, 1) knn2 <- knearneigh(coords, 2) nb1 <- knn2nb(knn1, row.names=rn) nb2 <- knn2nb(knn2, row.names=rn) diffs <- diffnb(nb2, nb1) plot(columbus, border="grey") plot(nb1, coords, add=TRUE) plot(diffs, coords, add=TRUE, col="red", lty=2) title(main="Plot of first (black) and second (red)\nnearest neighbours")