Colour, size, shape and other aesthetic attributes

• ggplot2 takes care of the details of converting data (e.g., ‘f’, ‘r’, ‘4’) into aesthetics (e.g., ‘red’, ‘yellow’, ‘green’) with a scale.

ggplot(mpg, aes(displ, hwy, colour = class)) + 
  geom_point()

• no ‘scaling’

ggplot(mpg, aes(displ, hwy)) + geom_point(colour = "blue")

ggplot(mpg, aes(displ, hwy)) + geom_point(aes(colour = "blue"))

• the second plots doesn’t have a legend
• think about how to colour
• tell a story
• less is more!