16.4. Interactive graphs

The base installation of R provides limited interactivity with graphs. You can modify graphs by issuing additional program statements, but there’s little that you can do to modify them or gather new information from them using the mouse. However, there are contributed packages that greatly enhance your ability to interact with the graphs you create. In this section, we’ll focus on functions provided by the playwith, latti-cist, iplots, and rggobi packages. Be sure to install them before first use.

16.4.1. Interacting with graphs: identifying points

Before getting to the specialize packages, let’s review a function in the base R installation that allows you to identify and label points in scatter plots. Using the identify() function, you can label selected points in a scatter plot with their row number or row name using your mouse. Identification continues until you select Stop or right-click on the graph. For example, after issuing the following statements