CODEWITHSUNDEEP
rggplot2
Julio Diaz
Julio Diaz

Reputation: 9427

Sort legend in ggplot2

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
4,90,163,140
5,206,280,200
6,1389,1080,1075
7,3983,3258,4878
8,7123,15828,28111
9,8608,48721,52576
10,9639,44725,55951
11,8323,45695,32166
12,2496,18254,26600
13,1524,8591,18583
14,7861,1857,1680
15,10269,5165,4618
16,13560,64636,63262

using the following code

library(ggplot2)
library(reshape2)
library(scales)

data <- read.csv(file="file.csv",sep=",",header=TRUE)
data <- data[,2:ncol(data)]
datam <- melt(cbind(data,ind = sort(rownames(data))),is.var = c('ind'))
datam$ind <- as.numeric(datam$ind)
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")

The result is enter image description here

The problem is that the items in the legend are not in the same order as the stacks they represent. The colours and the numbers are right but the order is not. In other words, is there a way to invert the order of the items in the legend? Thanks

Upvotes: 20

Views: 9074

Answers (2)

kohske
kohske

Reputation: 66842

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))

enter image description here

Upvotes: 32

Tyler Rinker
Tyler Rinker

Reputation: 109844

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.

Upvotes: 4

Related Questions