R: changing color of stacked barplot

问题:

library(ggplot2)
df2 <- data.frame(supp=rep(c("VC", "OJ"), each=3),
                dose=rep(c("D0.5", "D1", "D2"),2),
                len=c(6.8, 15, 33, 4.2, 10, 29.5))
head(df2)
ggplot(data=df2, aes(x=dose, y=len, fill=supp)) +
  geom_bar(stat="identity")

I have a simple stacked barplot, and I would like to change the colors manually. More specifically, I would like to flip the colors used for fill = supp (i.e. teal for OJ instead). I've trid adding a color = ... parameter into geom_bar but that simply outlines the barplots instead of coloring them in.

回答1:

ggplot(data=df2, aes(x=dose, y=len, fill=supp)) +
  geom_bar(stat="identity")+scale_fill_manual(values = c("Green","tomato"))