plot.nb {spdep} | R Documentation

## Plot a neighbours list

### Description

A function to plot a neighbours list given point coordinates to represent the region in two dimensions; `plot.listw` is a wrapper that passes its neighbours component to `plot.nb`.

### Usage

    plot.nb(x, coords, col="black", points=TRUE, add=FALSE, arrows=FALSE,
     length=0.1, xlim=NULL, ylim=NULL, ...)
    plot.listw(x, coords, col="black", points=TRUE, add=FALSE, arrows=FALSE,
     length=0.1, xlim=NULL, ylim=NULL, ...)

### Arguments

`x` | an object of class `nb` or (for `plot.listw`) class `listw`
`coords` | matrix of region point coordinates
`col` | plotting colour
`points` | (logical) add points to plot
`add` | (logical) add to existing plot
`arrows` | (logical) draw arrowheads for asymmetric neighbours
`length` | length in plot inches of arrow heads drawn for asymmetric neighbours lists
`xlim, ylim` | plot window bounds
`...` | further graphical parameters as in `par(..)`

### Author(s)

Roger Bivand Roger.Bivand@nhh.no

### See Also

`summary.nb`

### Examples

    example(columbus)
    coords <- coordinates(columbus)
    plot(col.gal.nb, coords)
    title(main="GAL order 1 links with first nearest neighbours in red")
    col.knn <- knearneigh(coords, k=1)
    plot(knn2nb(col.knn), coords, add=TRUE, col="red", length=0.08)

[Package spdep version 0.4-56 Index]