R: Neighbours list from knn object

knn2nb {spdep} | R Documentation

## Neighbours list from knn object

### 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

    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 Roger.Bivand@nhh.no

### See Also

`knearneigh`, `card`

### Examples

    columbus <- st_read(system.file("shapes/columbus.shp", package="spData")[1], quiet=TRUE)
    coords <- coordinates(as(columbus, "Spatial"))
    col.knn <- knearneigh(coords, k=4)
    plot(st_geometry(columbus), border="grey")
    plot(knn2nb(col.knn), coords, add=TRUE)
    title(main="K nearest neighbours, k = 4")

[Package spdep version 1.2-2 Index]