Boxplot show the value of mean

Question

In this boxplot we can see the mean but how can we have also the number value on the plot for every mean of every box plot?

 ggplot(data=PlantGrowth, aes(x=g         


        

Answer 1

The Magrittr way

I know there is an accepted answer already, but I wanted to show one cool way to do it in single command with the help of magrittr package.

PlantGrowth %$% # open dataset and make colnames accessible with '$'
split(weight,group) %T>% # split by group and side-pipe it into boxplot
boxplot %>% # plot
lapply(mean) %>% # data from split can still be used thanks to side-pipe '%T>%'
unlist %T>% # convert to atomic and side-pipe it to points
points(pch=18)  %>% # add points for means to the boxplot
text(x=.+0.06,labels=.) # use the values to print text

This code will produce a boxplot with means printed as points and values:

I split the command on multiple lines so I can comment on what each part does, but it can also be entered as a oneliner. You can learn more about this in my gist.