knn2nb: Neighbours list from knn object

Description Usage Arguments Value Author(s) See Also Examples

View source: R/knn2nb.R

Description

The function converts a knn object returned by knearneigh into a neighbours list of class nb with a list of integer vectors containing neighbour region number ids.

Usage

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knn2nb(knn, row.names = NULL, sym = FALSE)

Arguments

knn

A knn object returned by knearneigh

row.names

character vector of region ids to be added to the neighbours list as attribute region.id, default seq(1, nrow(x))

sym

force the output neighbours list to symmetry

Value

The function returns an object of class nb with a list of integer vectors containing neighbour region number ids. See card for details of “nb” objects.

Author(s)

Roger Bivand [email protected]

See Also

knearneigh, card

Examples

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example(columbus)
coords <- coordinates(columbus)
col.knn <- knearneigh(coords, k=4)
plot(columbus, border="grey")
plot(knn2nb(col.knn), coords, add=TRUE)
title(main="K nearest neighbours, k = 4")

Example output

Loading required package: sp
Loading required package: Matrix

colmbs> require(maptools)
Loading required package: maptools
Checking rgeos availability: TRUE

colmbs> columbus <- readShapePoly(system.file("etc/shapes/columbus.shp",
colmbs+  package="spdep")[1])

colmbs> col.gal.nb <- read.gal(system.file("etc/weights/columbus.gal",
colmbs+  package="spdep")[1])
Warning message:
use rgdal::readOGR or sf::st_read 

spdep documentation built on Aug. 19, 2017, 3:01 a.m.