Baseball Hacks

Analyze Baseball with R

A short introduction to the R language and environment.

R is a terrific piece of software because it’s stable, powerful, and easy to use. It’s a great tool for doing many different things, including creating simple calculations and charts, building complex visualizations, and even building statistical models. This hack will give you enough of an overview to enable you to do really sophisticated studies that would be difficult or impossible to do in a tool like Excel.

Let’s start by taking a look at the R environment. R includes a toolbar with some commonly used operations; a console window; and windows showing graphical output, help, edit windows, and other results. See Figure 4-2 for an illustration. The R environment looks a little different on Mac OS, Linux, and other Unix variants, but the language and tools are the same.

Notice the window with the > prompts and the messages. This is the console window. This is the primary way you communicate with R. Just type an expression in the window and press Return; R responds with results and errors when appropriate.

The GUI includes a lot of familiar operations: you can save and load files; cut, copy, and paste things; and get help. The most interesting feature is the packages menu. R packages are similar to browser plug-ins because they extend the functionality of R. The GUI lets you load packages that are stored locally, or install and update packages from the Internet.

Calculations in R

Let’s start with a few simple ...