Visualizing Relationships - Data Points: Visualization That Means Something - page 219

FIGurE 6-35 Histogram matrix refined in Illustrator
This isn't the only way to do things. You could create the same matrix with
Processing, Protovis, PHP, or anything that draws bars. There are even
multiple ways to make the same type of matrix within R. For example, I
made a graphic for FlowingData on the changing distribution of television
sizes from 2002 through 2009, as shown in Figure 6-36.