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.
Deze oefening maakt deel uit van de cursus
Intermediate Data Visualization with ggplot2
Praktische interactieve oefening
Probeer deze oefening eens door deze voorbeeldcode in te vullen.
ggplot(mtcars, aes(wt, mpg)) +
geom_point() +
# Facet rows by am using formula notation
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