ggplot2 使用计数的条形图标签

Question

In the code below, how do I add label to each bar showing its count? Thanks

library(ggplot2)
data(iris)
ggplot(iris) +
    geom_bar(aes_string(x="Species"), fill="steelblue") +
#   geom_text(aes(label="Species")) +          # does not work
    theme(axis.text.y = element_blank(),
          axis.ticks.y = element_blank(),
          axis.title.y = element_blank()
         )

Answer 1

You can try this:

library(tidyverse)
#Data
data(iris)
#Plot
ggplot(iris) +
  geom_bar(aes_string(x="Species"), fill="steelblue") +
  geom_text(data= iris %>% group_by(Species) %>% summarise(N=n()),
            aes(x=Species,y=N,label=N),position = position_stack(vjust = 0.5))+
  theme(axis.text.y = element_blank(),
        axis.ticks.y = element_blank(),
        axis.title.y = element_blank()
  )

Output:

You can also try a different position for labels with this:

ggplot(iris) +
  geom_bar(aes_string(x="Species"), fill="steelblue") +
  geom_text(data= iris %>% group_by(Species) %>% summarise(N=n()),
            aes(x=Species,y=N,label=N),position = position_dodge(width = 0.9),vjust=-0.5)+
  theme(axis.text.y = element_blank(),
        axis.ticks.y = element_blank(),
        axis.title.y = element_blank()
  )

Output: