Beyond Spreadsheets with R

8 Doing things conditionally: Control structures

This chapter covers

• Looping over sections of code
• Conditionally evaluating code
• Best practices to balance speed and readability

You saw in chapter 6 that you can conditionally select elements from data structures, but sometimes you only want to do (or not do) something based on some condition, or do something many times with slightly different conditions. There may be many steps you want to conditionally perform, so you need a way to only do things sometimes (or many times). You can use several approaches to do this in R, so let’s look at the most common and the most useful, as well as some other ways these tasks can be accomplished.

8.1 Looping

So far, you’ve evaluated code in a very linear ...