How to Reverse the Ordering of a ggplot2 Plot Legend in R (Example Code)

data(iris)                     # Loading example data
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 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 ggplot2 package
library("ggplot2")             # Load ggplot2 package

install.packages("ggplot2") # Install ggplot2 package library("ggplot2") # Load ggplot2 package

my_plot <- ggplot(iris,        # Drawing ggplot2 plot with default legend
              aes(x = Sepal.Length,
                  y = Sepal.Width,
                  col = Species)) +
  geom_line()
my_plot                        # Draw plot

my_plot <- ggplot(iris, # Drawing ggplot2 plot with default legend aes(x = Sepal.Length, y = Sepal.Width, col = Species)) + geom_line() my_plot # Draw plot

my_plot +                      # Reversing the legend order
  guides(col = guide_legend(reverse = TRUE))

my_plot + # Reversing the legend order guides(col = guide_legend(reverse = TRUE))