Facet layer basics
Faceting splits the data up into groups, according to a categorical variable, then plots each group in its own panel. For splitting the data by one or two categorical variables, facet_grid() is best.
Given categorical variables A and B, the code pattern is
plot +
facet_grid(rows = vars(A), cols = vars(B))
This draws a panel for each pairwise combination of the values of A and B.
Here, we'll use the mtcars data set to practice. Although cyl and am are not encoded as factor variables in the data set, ggplot2 will coerce variables to factors when used in facets.
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
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