Scatterplots

Scatterplots are commonly used to visualize the relationship between two continuous variables. For example, you may be interested in the relationship between body mass and bill length across all islands:

ggplot(data = penguins, 
       mapping = aes(x = bill_length_mm, y = body_mass_g)) +
  geom_point()

The above code first specifies the data (penguins). The mapping arguments define “which variables belong where”. In this case, bill_length_mm is on the x axis, body_mass_g on the y. The geom of geom_point specifies that this is a scatterplot.

You could add the visual variable of color to show patterns within each island:

ggplot(data = penguins, 
       mapping = aes(x = bill_length_mm, y = body_mass_g, color = island)) +
  geom_point()