multiplot: Calculates confidence intervals for different probabiity levels for pairs of data points.
Description
A multiple plot function, allowing ggplot2 objects to be plotted together. If the layout is something like matrix(c(1,2,3,3), nrow=2, by.row=TRUE),
then plot 1 will go in the upper left, 2 will go in the upper right, and 3 will go all the way across the bottom.
Borrowed with thanks from http://wiki.stdout.org/rcookbook/Graphs/Multiple