spdep (version 0.1-10)

knearneigh: K nearest neighbours for spatial weights

Description

The function returns a matrix with the indices of regions belonging to the set of the k nearest neighbours of each other.

Usage

knearneigh(x, k=1)

Arguments

x

matrix of region point coordinates

k

number of nearest neighbours to be returned

Value

• A list of class knn
• nn
  integer matrix of region number ids
• np
  number of input points
• k
  input required k
• dimension
  number of columns of x
• x
  input coordinates

Details

The underlying C code is based on the knn function in the class package in the VR bundle.

See Also

knn, dnearneigh, knn2nb

Examples

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