Week 4

mutate(), case_when(), summarize(), group_by(), across(), more ggplot2

Topics

• Learn and apply mutate() to change the data type of a variable
• Apply mutate() to calculate a new variable based on other variables in a data.frame.
• Apply case_when in a mutate() statement to make a continuous variable categorical
• Learn how to mutate() across() multiple columns at once.
• Learn how to summarize() data with group_by() to summarize within categories
• Learn to facet and change scales/palettes of ggplots.

Announcements

• Class materials for BSTA 526 will be provided in the shared Dropbox folder BSTA_526_W25_class_materials_public.
• For today’s class, make sure to download to your computer the folder called part_04, and then open RStudio by double-clicking on the file called part_04.Rproj.
• If you have not already done so, please join the BSTA 526 Slack channel and introduce yourself by posting in the #random channel.

Class materials

• Readings
• Dropbox part_04 Project folder

Post-class survey

• Please fill out the post-class survey to provide feedback. Thank you!
• Previous muddiest points and clearest points with responses are collected here: https://niederhausen.github.io/BSTA_526_W25/survey_feedback_previous_years

Homework

• See Dropbox folder for homework assignment.
• HW 4 due on 2/6.

Recording

• In-class recording links are on Sakai. Navigate to Course Materials -> Schedule with links to in-class recordings. Note that the password to the recordings is at the top of the page.