Ahmad Mousavi

Ahmad Mousavi

Assistant Prof. of Data Science,
Dept. of Math. and Stat.,
American University

Lab 7: Tidying Data

DATA 412/612 · Week 7 · PDF · Source (.qmd)

Pivot monkeymem and the flower files. Unite a few flight columns.

Work in a Quarto document. Do 7.1 and 7.2 first. Put the course CSV files in a data/ folder of your project (see the Data section of the course page).

library(tidyverse)
library(nycflights13)

1. Longer

  1. Load monkeymem.csv. Pivot Week2 through Week16 longer. Each row should be one monkey-week. The week names go in one column; accuracy goes in another.
  2. On table4a, show a pivot_longer() call that fails because the year names are written as numbers, then the call that works. In a sentence, why the first one fails.
  3. Pivot monkeymem.csv again with names_prefix = "Week" and names_transform so the week column is an integer. In a sentence, what type was that column before the transform?

2. Wider, separate, unite

  1. Load flowers1.csv with read_delim("data/flowers1.csv", delim = ";"). Widen so Variable becomes column names and Value fills the cells. Fix the decimal commas if Value is not numeric.
  2. Load flowers2.csv. Separate Flowers/Intensity into two numeric columns. Unite those two columns again with a comma.
  3. In flights, select month, day, hour, and minute. Unite hour and minute into sd_time, then parse that column as a time. What happens, and why? Fix it with paste0() or stringr so minutes stay two digits.