r - Plot title at bottom of plot using ggplot2

Question

In ggplot2, how to put the plot title at the bottom of the plot.

qplot(rnorm(100)) + ggtitle("My Title")

puts the title at middle and top of plot, while I want it to be at middle and bottom of the plot.

Answer 1

Here is a solution using grid.text:

library("grid")
qplot(rnorm(100)) + theme(plot.margin=unit(c(0.5, 1, 2, 0.5), "lines"))
grid.text("My Title", x = unit(0.5, "npc"), y = unit(0, "npc"),
          vjust = -0.5, gp = gpar(cex=1.2))