How to Draw a Legend to Base R Graph (Example Code)

data(iris)                         # Iris data set as example data
head(iris)                         # Print head of iris data set
#   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) # Iris data set as example data head(iris) # Print head of iris data set # 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

plot(x = iris$Sepal.Length,        # Draw plot
     y = iris$Sepal.Width,
     col = iris$Species)
legend("topright",                 # Add legend
       legend = levels(iris$Species),
       col = 1:3,
       pch = 1)

plot(x = iris$Sepal.Length, # Draw plot y = iris$Sepal.Width, col = iris$Species) legend("topright", # Add legend legend = levels(iris$Species), col = 1:3, pch = 1)