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.
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
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