plot.nb: Plot a neighbours list

Description Usage Arguments Author(s) See Also Examples

View source: R/plot.nb.R

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

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## S3 method for class 'nb'
plot(x, coords, col="black", points=TRUE, add=FALSE, arrows=FALSE,
 length=0.1, xlim=NULL, ylim=NULL, ...)
## S3 method for class 'listw'
plot(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 [email protected]

See Also

summary.nb

Examples

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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)

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 Sept. 2, 2017, 1:11 a.m.