Data Analysis with R, Second Edition - Second Edition

Navigating the basics

In the interactive R interpreter, any line starting with a > character denotes R asking for input. (If you see a + prompt, it means that you didn't finish typing a statement at the prompt and R is asking you to provide the rest of the expression). Striking the return key will send your input to R to be evaluated. R's response is then spit back at you in the line immediately following your input, after which R asks for more input. This is called a REPL (Read-Evaluate-Print-Loop). It is also possible for R to read a batch of commands saved in a file (unsurprisingly called batch mode), but we'll be using the interactive mode for most of the book.

As you might imagine, R supports all the familiar mathematical operators as ...