Drawing bivariate dot plots using ggplot2

Dot plots are commonly used to plot univariate discrete distributions. Dots are stacked and each dot represents a fixed number of occurrences. However, that is not the only usage. They can also represent bivariate and multivariate relations. ggplot2 has a function fully dedicated to draw dot plots, but there are alternatives. They can also drawn by using geom_point() or geom_jitter() instead, as later recipes will demonstrate. They can also be seen as supplemental devices to box and violin plots.

This recipe teaches how to use the fully dedicated function, geom_dotplot(), in order to create simple dot plots. It also highlights an important aspect of dot plots built this way, proportions.