Create test data group = c(rep(A, 3), rep(B, 6), rep(C, 5),rep(D, 4)) value-c(rnorm(3,mean=1,sd=4),rnorm(6,mean=0,sd=1),rnorm(5,mean=2,sd=2),rnorm(4,mean=5,sd=1)) tt.data-data.frame(group,value) head(tt.data) Now plot library(ggplot2) ggplot(tt.data,aes(grou ...