How to add a number of observations per group and use group mean in ggplot2 boxplot?

Question

I am doing a basic boxplot where y=age and x=Patient groups

age <- ggplot(data, aes(factor(group2), age))  + ylim(15, 80) 
age         


        

Answer 1

Answer to the first problem. To show value above the box you should provide x values as numeric not as level names. So, to plot the value above first value give x=1.

data(ToothGrowth)
ggplot(ToothGrowth,aes(supp,len))+geom_boxplot()+
   annotate("text",x=1,y=32,label=30)