Adding Aesthetics and Layers

• Aesthetics = visual properties of the plot.
• More aesthetics may tell the data’s story better.
• Types of aesthetic mapping:
  • coordinates: x and y
  • linewidth
  • shape
  • color
  • fill
  • alpha (transparency)
  • stroke
  • linetype
  • group
  • show.legend
  • others, sometimes specific to geom

ggplot(
  data = penguins,
  mapping = aes(
    x = flipper_length_mm, 
    y = body_mass_g, 
    color = species
  )
) +
  geom_point()