nb.set.operations {spdep} | R Documentation |
Set operations on neighbors list objects
intersect.nb(nb.obj1,nb.obj2) union.nb(nb.obj1,nb.obj2) setdiff.nb(nb.obj1,nb.obj2) complement.nb(nb.obj)
nb.obj |
a neighbor list created from any of the neighborhood list funtions |
nb.obj1 |
a neighbor list created from any of the neighborhood list funtions |
nb.obj2 |
a neighbor list created from any of the neighborhood list funtions |
These functions perform set operations on each element of a neighborlist. The arguments must be neighbor lists created from the same coordinates, and the region.id attributes must be identical.
nb.obj |
A new neighborlist created from the set operations on the input neighbor list(s) |
Nicholas Lewin-Koh nikko@hailmail.net
intersect.nb
, union.nb
,
setdiff.nb
example(columbus) coords <- coordinates(columbus) col.tri.nb <- tri2nb(coords) oldpar <- par(mfrow=c(1,2)) col.soi.nb <- graph2nb(soi.graph(col.tri.nb, coords)) plot(columbus, border="grey") plot(col.soi.nb, coords, add=TRUE) title(main="Sphere of Influence Graph") plot(columbus, border="grey") plot(complement.nb(col.soi.nb), coords, add=TRUE) title(main="Complement of Sphere of Influence Graph") par(mfrow=c(2,2)) col2 <- droplinks(col.gal.nb, 21) plot(intersect.nb(col.gal.nb, col2), coords) title(main="Intersect") plot(union.nb(col.gal.nb, col2), coords) title(main="Union") plot(setdiff.nb(col.gal.nb, col2), coords) title(main="Set diff") par(oldpar)