Annotate boxplot in ggplot2

Question

I created side by side using ggplot2.

p <- ggplot(mtcars, aes(x=factor(cyl), y=mpg))
p + geom_boxplot(aes(fill=factor(cyl)))

I want to comment with min, max, 1st quartile, median and 3rd quartile in the plot. I know I geom_text()can do this and can be fivenum()useful. But I can’t understand how exactly I can do it! These values ​​should be displayed on my chart.

Answer 1

The most concise way I can think of is to use stat_summary. I also matched labels with color aesthetics, but you can, of course, set labels to the same color if you want:

ggplot(mtcars, aes(x=factor(cyl), y=mpg, fill=factor(cyl))) + 
  geom_boxplot(width=0.6) +
  stat_summary(geom="text", fun.y=quantile,
               aes(label=sprintf("%1.1f", ..y..), color=factor(cyl)),
               position=position_nudge(x=0.33), size=3.5) +
  theme_bw()

quantile . ..y.. quantile ( ..*.. ggplot , ggplot).

Answer 2

- data.frame geom_text geom_label:

library(dplyr)

cyl_fivenum <- mtcars %>% 
    group_by(cyl) %>% 
    summarise(five = list(fivenum(mpg))) %>% 
    tidyr::unnest()

ggplot(mtcars, aes(x=factor(cyl), y=mpg)) + 
    geom_boxplot(aes(fill=factor(cyl))) + 
    geom_text(data = cyl_fivenum, 
              aes(x = factor(cyl), y = five, label = five), 
              nudge_x = .5)

Answer 3

, - log10 Y, , . 10^..y.. scale_y_log10(). 10^ ..y.. ..y.. .

ggplot(mtcars, aes(x=factor(cyl), y=mpg, fill=factor(cyl))) + 
  geom_boxplot(width=0.6) +
  stat_summary(geom="text", fun.y=quantile,
           aes(label=sprintf("%1.1f", ..y..), color=factor(cyl)),
           position=position_nudge(x=0.45), size=3.5) +
  scale_y_log10()+
  theme_bw()

ggplot(mtcars, aes(x=factor(cyl), y=mpg, fill=factor(cyl))) + 
  geom_boxplot(width=0.6) +
  stat_summary(geom="text", fun.y=quantile,
           aes(label=sprintf("%1.1f", 10^..y..), color=factor(cyl)),
           position=position_nudge(x=0.45), size=3.5) +
  scale_y_log10()+
  theme_bw()