Ahmad Mousavi

Ahmad Mousavi

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

Lab 5: dplyr, Part 2

DATA 412/612 · Week 5 · PDF · Source (.qmd)

Row-wise maxima, across(), case_when(), and row names.

Work in a Quarto document. Do 5.1 and 5.2 first. starwars comes with dplyr.

library(tidyverse)

1. Row-wise and across

  1. For each starwars character, the maximum of height, mass, and birth_year (na.rm = TRUE). Who is largest? Run it with rowwise() and once without.
  2. Median of every numeric column, by species and gender, plus n(), sorted by n descending.
  3. Min and max of every numeric column except birth_year, by species and gender, plus n().

2. case_when and row names

  1. Add a type column to starwars: "large" if height or mass is over 200, "robot" if the species is Droid, otherwise "other".
  2. Does mtcars have row names? If so, make a tibble with a car column.
  3. Distinct combinations of the starwars columns whose names contain "color".