r - ggplot : update facet labels with number of points in the plot

Question

我有一个数据集 data并且可以根据如下的要求进行绘图:

#Data
data <- data.frame(level = c(1,2,3,5,2,4,3,1,3), 
                   pay1 = c(10,21,32,12,41,21,36,14,17), 
                   pay2 = c(26,36,5,6,52,12,18,17,19))

#Plot
data %>% pivot_longer(-level) %>%
  ggplot(aes(x = name, y = value))+
  geom_boxplot() + 
  facet_wrap(~ level, scales = "free_x") +
  theme_bw()

我希望根据另一个变量 level 的频率更新构面标签.

table(data$level)
# 1 2 3 4 5 
# 2 2 3 1 1 

如何将 Facet 标签更新为 1 (n=2) , 2 (n=2) , 3 (n=3) , 4 (n=1) , 5 (n=1) ??

Answer 1

我只想用 mutate 重命名因子水平使用 paste 的调用和 n() :

data %>% 
  pivot_longer(-level) %>%
  group_by(level, name) %>%
  mutate(level = paste0(level, " (n = ", n(), ")")) %>%
  ggplot(aes(x = name, y = value))+
  geom_boxplot() + 
  facet_wrap(~ level, scales = "free_x") +
  theme_bw()