moran.plot.Rd
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.
moran.plot(x, listw, zero.policy=attr(listw, "zero.policy"), spChk=NULL, labels=NULL,
xlab=NULL, ylab=NULL, quiet=NULL, plot=TRUE, return_df=TRUE, ...)
a numeric vector the same length as the neighbours list in listw
a listw
object created for example by nb2listw
default attr(listw, "zero.policy")
as set when listw
was created, if attribute not set, use global option value; if TRUE assign zero to the lagged value of zones without neighbours, if FALSE assign NA
should the data vector names be checked against the spatial objects for identity integrity, TRUE, or FALSE, default NULL to use get.spChkOption()
character labels for points with high influence measures, if set to FALSE, no labels are plotted for points with large influence
label for x axis
label for x axis
default NULL, use !verbose global option value; if TRUE, output of summary of influence object suppressed
default TRUE, if false, plotting is suppressed
default TRUE, invisibly return a data.frame object; if FALSE invisibly return an influence measures object
further graphical parameters as in par(..)
The function returns a data.frame object with coordinates and influence measures if return_df
is TRUE, or an influence object from influence.measures
.
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
data(afcon, package="spData")
mp <- moran.plot(afcon$totcon, nb2listw(paper.nb),
labels=as.character(afcon$name), pch=19)
moran.plot(as.vector(scale(afcon$totcon)), nb2listw(paper.nb),
labels=as.character(afcon$name), xlim=c(-2, 4), ylim=c(-2,4), pch=19)
if (require(ggplot2, quietly=TRUE)) {
xname <- attr(mp, "xname")
ggplot(mp, aes(x=x, y=wx)) + geom_point(shape=1) +
geom_smooth(formula=y ~ x, method="lm") +
geom_hline(yintercept=mean(mp$wx), lty=2) +
geom_vline(xintercept=mean(mp$x), lty=2) + theme_minimal() +
geom_point(data=mp[mp$is_inf,], aes(x=x, y=wx), shape=9) +
geom_text(data=mp[mp$is_inf,], aes(x=x, y=wx, label=labels, vjust=1.5)) +
xlab(xname) + ylab(paste0("Spatially lagged ", xname))
}