6 Boxplot

In this chapter, we introduce the boxplot in ggplot2 style.

6.1 basic

We use iris dataset for illustration.

library(ggplot2)
library(dplyr)
library(patchwork)

data("iris")
head(iris)

##   Sepal.Length Sepal.Width Petal.Length Petal.Width Species
## 1          5.1         3.5          1.4         0.2  setosa
## 2          4.9         3.0          1.4         0.2  setosa
## 3          4.7         3.2          1.3         0.2  setosa
## 4          4.6         3.1          1.5         0.2  setosa
## 5          5.0         3.6          1.4         0.2  setosa
## 6          5.4         3.9          1.7         0.4  setosa

ggplot(iris, aes(x=Species, y=Sepal.Length)) +
  geom_boxplot()

6.2 With color or fill

p1 <- ggplot(iris, aes(x=Species, y=Sepal.Length)) +
  geom_boxplot(aes(fill=Species))

p2 <- ggplot(iris, aes(x=Species, y=Sepal.Length)) +
  geom_boxplot(aes(color=Species))

p1 + p2