Importing and recoding data

Lecture 10

John Zito

Duke University
STA 199 Spring 2026

2026-02-16

While you wait: Participate 📱💻

To keep some rows in a data frame and discard others, I use BLANK. To keep some columns and discard others, I use BLANK.

  • group_by; arrange;
  • filter; select;
  • bye row; seeya column;
  • a shovel; your bear hands;
  • select; filter

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On the horizon

Spring break is three weeks away. Here’s what happens in the meantime:

  • Wed Feb 18: submit HW 4;
  • Thu Feb 19: JZ posts Midterm 1 study-guide;
  • Thu Feb 19: meet project teams and start proposal;
  • Sun Feb 22: proposal due;
  • Wed Feb 25: Midterm 1 in-class;
  • Thu Feb 26: proposal feedback returned;
  • Thu Feb 26: Midterm 1 take-home posted;
  • Sun Mar 01: submit Midterm 1 take-home;
  • Thu Mar 05: make some major project progress.

After that, I forbid any of us from thinking about this class until March 16 at the earliest.

Reading data into R

Reading rectangular data

  • Using readr:
    • Most commonly: read_csv()
    • Maybe also: read_tsv(), read_delim(), etc.
  • Using googlesheets4: read_sheet() – We haven’t covered this in the videos, but might be useful for your projects

Application exercise

Reading and writing CSV files

  • Read a CSV file

  • Split it into subsets based on features of the data

  • Write out subsets as CSV files

Age gap in Hollywood relationships

What is the story in this visualization?