R: Make legend labels

leglabs {maptools} | R Documentation

## 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(s)

Roger Bivand Roger.Bivand@nhh.no

### 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"))

[Package maptools version 0.9-9 Index]