draw the sum value above the stacked bar in ggplot2

Question

How do I draw the sum value of each class (in my case: a=450, b=150, c=290, d=90) above the stacked bar in ggplot2？ Here is my code：

#Data
hp=read.csv(textCo         


        

Answer 1

You can use the built-in summary functionality of ggplot2 directly:

ggplot(hp, aes(reorder(class, -amount, sum), amount, fill = year)) +
  geom_col() +
  geom_text(
    aes(label = stat(y), group = class), 
    stat = 'summary', fun = sum, vjust = -1
  )