Short legend height in rastervis plot of categorical raster

Question

In plotting categorical raster maps with levelplot, such as Josh O'Brien's answer here Legend of a raster map with categorical data, the legend height always become shorter. Is there a way to adjust the legend height the same height as the plot window?

Answer 1

You can set the legend height by passing colorkey=list(height=1) to the levelplot function.

library(raster)
library(rasterVis)

## Example data
r <- raster(ncol=4, nrow=2)
r[] <- sample(1:4, size=ncell(r), replace=TRUE)
r <- as.factor(r)

## Add a landcover column to the Raster Attribute Table
rat <- levels(r)[[1]]
rat[["landcover"]] <- c("land","ocean/lake", "rivers","water bodies")
levels(r) <- rat

## Plot
levelplot(r, colorkey=list(height=1), col.regions=rev(terrain.colors(4)), xlab="", ylab="")