Sort legend in ggplot2

Question

I have produced a stacked percent barplot from the following data, which is in a csv file,

,ONE,TWO,THREE
1,2432,420,18
2,276,405,56
3,119,189,110
4,90,163,1         


        

Answer 1

you can use a new option reverse = TRUE:

ggplot(datam,aes(x = variable, y = value,fill = factor(as.numeric(ind)))) +
  geom_bar(position = "fill") + scale_y_continuous(labels =percent_format()) +
  scale_fill_discrete("Barcode\nMatch") + xlab("Barcode")+ylab("Reads") +
  guides(fill = guide_legend(reverse = TRUE))

Answer 2

Add + scale_fill_hue(breaks=c("new order 1","new order 2","new order...")) as in:

library(ggplot2)
ggplot(data=PlantGrowth, aes(x=group, fill=group)) + geom_bar() + 
    geom_bar(colour="black", legend=FALSE) + 
    scale_fill_hue(breaks=c("trt1","ctrl","trt2"))

I'd also check out http://wiki.stdout.org/rcookbook/Graphs/Legends%20(ggplot2)/ for more.

This may have changed and become easier with he new ggplot but I'm not sure.