Formula notation
As well as the vars()
notation for specifying which variables should be used to split the dataset into facets, there is also a traditional formula notation. The three cases are shown in the table.
| Modern notation | Formula notation |
|--------------------------------------------|-------------------|
| facet_grid(rows = vars(A)) | facet_grid(A ~ .) |
| facet_grid(cols = vars(B)) | facet_grid(. ~ B) |
| facet_grid(rows = vars(A), cols = vars(B)) | facet_grid(A ~ B) |
mpg_by_wt
is available again. Rework the previous plots, this time using formula notation.
This exercise is part of the course
Intermediate Data Visualization with ggplot2
Hands-on interactive exercise
Have a go at this exercise by completing this sample code.
ggplot(mtcars, aes(wt, mpg)) +
geom_point() +
# Facet rows by am using formula notation
___