在ggplot2中对图例进行排序

Question

我从以下数据中生成了堆积百分比条形图,该数据位于csv文件中,

,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

使用以下代码

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")

结果是

问题是图例中的项目与它们所代表的堆栈的顺序不同.颜色和数字是正确的,但顺序不是.换句话说,有没有办法颠倒图例中项目的顺序？谢谢

Answer 1

你可以使用一个新选项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))