Reorder ggplot2 Boxplot by Median Values in R (Example Code)

data(iris)                        # Loading example data frame
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

data(iris) # Loading example data frame 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

install.packages("ggplot2")       # Install & load ggplot2 package
library("ggplot2")

install.packages("ggplot2") # Install & load ggplot2 package library("ggplot2")

ggplot(iris,                      # Drawing ggplot2 boxplot with unordered boxes
       aes(x = Species,
           y = Sepal.Width)) +
  geom_boxplot()

ggplot(iris, # Drawing ggplot2 boxplot with unordered boxes aes(x = Species, y = Sepal.Width)) + geom_boxplot()

Species_sort <- with(iris,        # Get ordering by median
                      reorder(Species,
                              Sepal.Width,
                              median))

Species_sort <- with(iris, # Get ordering by median reorder(Species, Sepal.Width, median))

iris_new <- iris                  # Reordering factor levels
iris_new$Species <- factor(iris_new$Species,
                           levels = levels(Species_sort))

iris_new <- iris # Reordering factor levels iris_new$Species <- factor(iris_new$Species, levels = levels(Species_sort))

ggplot(iris_new,                  # Drawing ggplot2 boxplot with ordered boxes
       aes(x = Species,
           y = Sepal.Width)) +
  geom_boxplot()

ggplot(iris_new, # Drawing ggplot2 boxplot with ordered boxes aes(x = Species, y = Sepal.Width)) + geom_boxplot()