Neighbord relationships below a certain distance threshold

neighbor.R

library(rgdal)
library(spdep)

pol <- readOGR(".", "buildings") # read the data using rgdal

nb <- poly2nb(pol, snap=50) # create a graph. Two buildings are connected if they are 50 meters apart from one another.

pol$nNeigh <- card(nb) # card(nb) gives the neighbor counts

pol$neighGroup <- n.comp.nb(nb)$comp.id # n.comp.nb contains the informations about the disconnected compontents