Chapter 15 Facets
An amazing features of ggplot, is facetting. Rather than explaining what they are, I will just show you:
ggplot(mpg, aes(x=cty)) + geom_histogram(binwidth=1) + facet_wrap(~manufacturer)
Facetting groups the data and displays the data for each group. This allows for comparing multiple groups readily. Let’s see some other examples. Remember this graph:
ggplot(mpg, aes(x=displ, y=cty, colour=drv)) +
geom_point() +
geom_smooth(method="lm", se=FALSE)
With facets:
ggplot(mpg, aes(x=displ, y=cty)) +
geom_point() +
geom_smooth(method="lm", se=FALSE) +
facet_wrap(~drv)
We can also put them under one another:
ggplot(mpg, aes(x=displ, y=cty)) +
geom_point() +
geom_smooth(method="lm", se=FALSE) +
facet_wrap(~drv, nrow=3)
Or use multiple variables with facet_grid
ggplot(mpg, aes(x=displ, y=cty)) +
geom_point() +
geom_smooth(method="lm", se=FALSE) +
facet_grid(year~drv)