| name | sex | total |
|---|---|---|
| Courtney | F | 257289 |
| Courtney | M | 22619 |
| Riley | F | 100881 |
| Riley | M | 92789 |
| Sarah | F | 1073895 |
| Sarah | M | 3320 |
Reshaping Data
Brianna Heggeseth
Announcements
Upcoming in MSCS
- MSCS BIPOC Affinity group meeting Feb 22 7-8:30pm in Smail Gallery
- Beyond Mac - Ava Cutler ’21; Monday, February 20th 4:45pm-5:45pm (OLRI 241)
- MSCS Seminar - Jodin Morey; Tuesday, February 21st 11:45am-12:45pm (OLRI 250)
Due this Week
- Assignment 5 (Six Main Verbs, Reshaping) next Wednesday [via Moodle]
- At least 1 Tidy Tuesday (TT) by next Friday [via Moodle, TT4 or TT5]
Learning Goals
- Understand the difference between wide and long data format and distinguish the case (unit of observation) for a given data set
- Develop comfort in using
pivot_widerandpivot_longerin thetidyrpackage
Template File
Download a template .Rmd of this activity. Put the file in a Assignment_05 folder within your COMP_STAT_112 folder.
- This .Rmd contains examples that we’ll work on in class and and 3 exercises you’ll finish for Assignment 5.
Describe to your Neighbor
Everyone: Look at this small data set.
Partner A: Describe the structure of the data set in words.
Describe to your Neighbor
Partner A: Close your eyes.
Partner B: Describe the how the structure of the data set changed. Think of describing “steps” taken.
Partner A: Sketch what you think the new data set looks like.
| name | F | M |
|---|---|---|
| Courtney | 257289 | 22619 |
| Riley | 100881 | 92789 |
| Sarah | 1073895 | 3320 |
Describe to your Neighbor
Partner B: Close your eyes.
Partner A: Describe the how the structure of the data set changed. Think of describing “steps” taken.
Partner B: Sketch what you think the new data set looks like.
| name | F | M | ratio |
|---|---|---|---|
| Courtney | 257289 | 22619 | 0.0879128 |
| Riley | 100881 | 92789 | 0.9197867 |
| Sarah | 1073895 | 3320 | 0.0030915 |
and then …
| name | ratio | sex | total |
|---|---|---|---|
| Courtney | 0.0879128 | F | 257289 |
| Courtney | 0.0879128 | M | 22619 |
| Riley | 0.9197867 | F | 100881 |
| Riley | 0.9197867 | M | 92789 |
| Sarah | 0.0030915 | F | 1073895 |
| Sarah | 0.0030915 | M | 3320 |
Wider V. Longer Format
If we want to retain all of the values in the data set (no summaries or combinations) but have a different unit of observation (or case), we can:
- Make the data wider by spreading out the values across new variables (e.g. total counts for binary “Male” and “Female” names)
- Make the data longer by combining values from different variables into 1 variable (take counts for binary “Male” and “Female” names and combine into one total column)
R Functions
pivot_wider()
- Inputs: data, names_from = var_nameA, values_from = var_nameB
pivot_longer()
- Inputs: data, cols = c(var_name1, var_name2), names_to = “newvarname_names”, values_to = “newvarname_values”
R Functions
In Class
Go through the example code in the Rmd file to make sure you understand how we reshape data to be wider and longer.
- Work together on the 3 exercises to turn in for Assignment 5.
After Class
- Work on the 3 exercises to turn in for Assignment 5.
- Tidy Tuesday 4 is posted in Moodle (due Friday).
