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.
Cet exercice fait partie du cours
Intermediate Data Visualization with ggplot2
Exercice interactif pratique
Essayez cet exercice en complétant cet exemple de code.
ggplot(mtcars, aes(wt, mpg)) +
geom_point() +
# Facet rows by am using formula notation
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