Line Graphs - R Graphics - page 86

Solution
Use geom_area() and map a factor to fill ( Figure 4-20 ):

library(gcookbook) # For the data set

ggplot(uspopage, aes(x = Year, y = Thousands, fill = AgeGroup)) + geom_area()

Figure 4-20. Stacked area graph

Discussion
The sort of data that is plotted with a stacked area chart is often provided in a wide format, but
ggplot2() requires data to be in long format. To convert it, see Converting Data from Wide to
Long .

In the example here, we used the uspopage data set:

uspopage

Year AgeGroup Thousands
1900 < 5 9181

1900 5 - 14 16966

1900 15 - 24 14951