Appendix

Data is from the team rosters on SwimCloud.

Todo list

• scrape a single page
• scrape a list of pages
• gather data in a single dataframe
• plot class size per year colored by class
• plot attrition lines per class

Running the scrape yourself

Assumes you already have npm installed

npm ci
npm run scrape

This should fill up the data/ directory with files. This is the file tree for just Carnegie Mellon, but the same file tree is reflective of every other school

$ tree data/
data
├── CMU
│   ├── 2011.csv
│   ├── 2012.csv
│   ├── 2013.csv
│   ├── 2014.csv
│   ├── 2015.csv
│   ├── 2016.csv
│   ├── 2017.csv
│   ├── 2018.csv
│   ├── 2019.csv
│   ├── 2020.csv
│   ├── 2021.csv

Plotting

Assume you already have R installed

npm run plot

Will generate the plots in the plots directory:

$ tree plots/
plots
├── all-time-class-count.png
├── class-attrition-by-year.png
├── class-proportion-by-year.png
├── class-size-by-year.png
├── relative-class-proportion-by-year.png
└── relative-class-size-by-year.png