ggplot2 : Plot mean with geom_bar

Question

I have the following data frame:

test2 <- data.frame(groups = c(rep(\"group1\",4), rep(\"group2\",4)), 
    X2 = c(rnorm(4), rnorm(4)) , 
    label = c(re         


        

Answer 1

simply use stat = "summary" and fun.y = "mean"

ggplot(test2) + 
  geom_bar(aes(label, X2, fill = as.factor(groups)), 
           position = "dodge", stat = "summary", fun.y = "mean")