Creating multi column legend in ggplot

Question

I have the following script, which suppose to create a plot with two column legend.

 #!/usr/bin/Rscript
library(ggplot2)
library(plyr)
library(reshape2)
libr         


        

Answer 1

you must assign the guide to the correct aesthetic and you used fill:

guides(fill=guide_legend(ncol=2))

And you should take care of the warning with geom_bar