Layer fundamentals: from user to potential extender

Gina Reynolds: ggplot2 extenders education

To start building a plot, you need to define the data and the variable encoding (i.e. what visual channels – color, x position, size etc – should represent your variables.)

library(ggplot2) 

ggplot(mpg) + 
  aes(x = hwy, y = cty) +
  theme_gray(base_size = 18)