Chapter 7. Special Applications of ggplot2
In this chapter, we will see some examples of applications of ggplot2 for creating particular kinds of plots. We will see how it is possible to include maps in plots as well as add data to such maps; we will see how to draw scatterplot matrices to represent the relationships between different variables; finally, we will see how to generate heat maps. Although, in principle, it is also possible to realize these plots using only ggplot2, in some cases it is a lot more convenient and faster to use additional packages where the particular plot layout is already implemented.
