Graphing Data with R

Part IV. Multivariable Graphs

Sometimes, we need to examine relationships among three or more variables—but the media we usually have available for graphs, such as paper or computer screens, are only two-dimensional objects. Although this presents challenges, a number of clever ways of visualizing higher-dimensional data have been devised. Some of these methods involve looking at pairs of variables at a time, usually with other pairs on the same page, so that we can readily make comparisons, whereas others attempt to display three or more variables in one plot. The next section examines a few promising graphical methods for multivariable visualization.