Wrap legend text in ggplot2

Question

Whilst producing graphs using ggplot2, I have some long legend names which I wish to wrap over two lines. For example:

a <- (1:10) b <- c(1,1.5,2,4,5,5.3,7,9,9.5,9.8) places = c("Birmingham","Chester-le-street","Cambridge", "Newcastle-upon-Tyne","Peterborough","Cambridge", "Newcastle-upon-Tyne","Peterborough","Liverpool","Stratford-upon-Avon") df1 = data.frame(a,b,places) library(ggplot2) i = ggplot(df1, aes(x=a, y=b)) + geom_point(aes(colour = places), size=3) + opts(legend.position="bottom") 

How would I go about wrapping the legend items when the box is set to be at the bottom - say in 2 or 3 lines? At the moment the seven items of the legend are next to each other. I would prefer that they are displayed in two rows (with say four towns on the top row and three towns on the second row).

Many thanks in advance.

Answer 1

Ok, given your edits, you probably wanted this:

library(scales) i + guides(colour = guide_legend(nrow = 2)) 

But you may find that you still want to employ the text wrapping technique as well, to get it to fit.