maptools (version 1.1-8)

leglabs: Make legend labels

Description

leglabs makes character strings from the same break points. The plot.polylist() function may be used as a generic S3 method.

Usage

leglabs(vec, under="under", over="over", between="-", reverse=FALSE)

Arguments

vec

vector of break values

under

character value for under

over

character value for over

between

character value for between

reverse

flag to reverse order of values, you will also need to reorder colours, see example

Author

Roger Bivand

See Also

findInterval

Examples

mappolys <- readShapeSpatial(system.file("shapes/columbus.shp", package="maptools")[1], ID="NEIGNO")
brks <- round(quantile(mappolys$CRIME, probs=seq(0,1,0.2)), digits=2)
colours <- c("salmon1", "salmon2", "red3", "brown", "black")
plot(mappolys, col=colours[findInterval(mappolys$CRIME, brks,
 all.inside=TRUE)])
legend(x=c(5.8, 7.1), y=c(13, 14.5), legend=leglabs(brks),
  fill=colours, bty="n")
title(main=paste("Columbus OH: residential burglaries and vehicle",
 "thefts per thousand households, 1980", sep="\n"))
#legend with reversed order
plot(mappolys, col=colours[findInterval(mappolys$CRIME, brks,
 all.inside=TRUE)])
legend(x=c(5.8, 7.1), y=c(13, 14.5), legend=leglabs(brks, reverse = TRUE),
  fill=rev(colours), bty="n")
title(main=paste("Columbus OH: residential burglaries and vehicle",
 "thefts per thousand households, 1980 (reversed legend)", sep="\n"))