ggplot2: Splitting facet/strip text into two lines

Question

Consider the following ggplot2 graph with long facet/strip text broken in two lines. The text goes outside the area devoted to facet titles.

library(ggplot2         


        

Answer 1

You can use a 2-line label:

grp <- c(rep("foo\nbar",3), 1, 1, 1)
qplot(x=x, y=y) + geom_line() + facet_wrap(~ grp)