Part 19 Selecting and sorting data frames

19.1 Learning Objectives

Here are the concepts we’ll be exploring in this lesson:

• tidyverse
• dplyr functions:
  • select()
  • arrange()
• piping

By the end of this lesson, students are expected to be able to:

• subset and rearrange data with dplyr
• use piping (|>) when implementing function chains

19.2 Preamble

Let’s talk about:

• The history of dplyr: plyr
  • Don’t use both in one script!
  • My recommendation, don’t use plyr at all at this point.
• tibbles are a special type of data frame
• The tidyverse
• Package functions and masking
  • Load the tidyverse package: library(tidyverse)

19.3 Demonstration

Let’s get started with an exercise:

1. Download this Rmd worksheet.
2. Save it to your class GitHub repo with a name like exercise-dplyr.Rmd.
3. Open the worksheet in RStudio.
4. Follow along in the .Rmd file until the Back to Guide section.