05. Tidying, Reshaping, and Ingesting Data

Published

Wednesday, September 16, 2026

This week …

More on dplyr: using across() to apply functions to multiple columns at once; using case_when() to create new variables based on conditions; reshaping data with pivot_longer(); importing and cleaning your data from plain-text and foreign binary formats.

Required Reading

  • Karl W. Broman and Kara H. Woo “Data Organization in Spreadsheets,” The American Statistician 72, no. 1 (January 2, 2018): 2–10, doi:10.1080/00031305.2017.1375989.
  • Hadley Wickham, Garrett Grolemund, and Mine Çetinkaya-Rundel R for Data Science: Import, Tidy, Transform, Visualize, and Model Data, 2nd ed. (Sebastopol, CA: O’Reilly Media, 2023), https://r4ds.hadley.nz. Read Chapter 7 on importing data. Read Chapter 20 on Spreadsheets. Read or review Chapter 17 on dates and times.

tidyr

stringr

  • Regular expressions
  • Read the help page for str_detect(): ?stringr::str_detect, which can also be found here. Work through the examples one at a time and make a note of any that seem confusing.

Examples

This week’s examples.

Assignment

This week’s assignment.

Slides