moran.plot: Moran scatterplot

Description

A plot of spatial data against its spatially lagged values, augmented by reporting the summary of influence measures for the linear relationship between the data and the lag. If zero policy is TRUE, such observations are also marked if they occur.

Usage

moran.plot(x, listw, zero.policy=FALSE, spChk=NULL, labels=NULL,
 xlab=NULL, ylab=NULL, ...)

Arguments

a numeric vector the same length as the neighbours list in listw

listw

a listw object created for example by nb2listw

zero.policy

if TRUE assign zero to the lagged value of zones without neighbours, if FALSE assign NA

spChk

should the data vector names be checked against the spatial objects for identity integrity, TRUE, or FALSE, default NULL to use get.spChkOption()

labels

character labels for points with high influence measures, if set to FALSE, no labels are plotted for points with large influence

xlab

label for x axis

ylab

label for x axis

...

further graphical parameters as in par(..)

Value

The function returns an influence object from influence.measures.

References

Anselin, L. 1996. The Moran scatterplot as an ESDA tool to assess local instability in spatial association. pp. 111--125 in M. M. Fischer, H. J. Scholten and D. Unwin (eds) Spatial analytical perspectives on GIS, London, Taylor and Francis; Anselin, L. 1995. Local indicators of spatial association, Geographical Analysis, 27, 93--115

Examples

Run this code

data(afcon)
moran.plot(spNamedVec("totcon", afcon), nb2listw(paper.nb),
 labels=as.character(afcon$name), pch=19)
moran.plot(scale(spNamedVec("totcon", afcon)), nb2listw(paper.nb),
 labels=as.character(afcon$name), xlim=c(-2, 4), ylim=c(-2,4), pch=19)