Data source

LRZ WiFi stats (Graphite), storage policy seems to be 5 minute buckets for the last 28 days and 15 minute buckets for at least several years.

Run download-stats.sh to download all stats since the grand opening on 9/11 2019.

How many people are there at peak hours?

cargo run -- --mode overview --ap-stats ap-stats.json > overview.csv
cd tex
pdflatex overview.tex

This graph shows the maximum number of people in the Mensa at any given day.

What's the best time for lunch?

cargo run -- --mode average --ap-stats ap-stats.json --since 2019-10-14 --until 2019-11-30 > average.csv
cd tex
pdflatex average.tex

Looks like 12:00 is the most popular time for lunch. The script filters days that seem to be holidays (Peak less than 10% of the median peak for that day).

Check out a specific day

cargo run -- --mode single --ap-stats ap-stats.json --day 2020-01-27 > single-day.csv
cd tex
pdflatex single-day.tex

Traffic on the busiest day yet: Monday, January 27th, 2020.

Pro-tipp: Re-download the stats with a custom from parameter if you want to render a day that is less than 4 weeks ago. This gives you data with 5 minute granularity.

Generating all the graphs

We've got an awesome makefile, just run make to generate all the PDFs and PNGs. (Requires curl, imagemagick, and a LaTeX installation with pdflatex and pgfplots.)

What's happening before and after lunch?

Also check out the off-peak hours (by modifying xmin/ymax or look at the CSV). The first shift of ~8 employees shows up at 6:00, followed by ~8 more people at 8:00. Almost all of them leave by 16:00. The most popular SSID is eduroam during Mensa opening hours, LRZ and BayernWLAN are most used before and after.

Wouldn't it be easier to just query Graphite?

Yes, but we want to print these graphs and PGFPlots is pretty!

How many people are in the Mensa right now?

Check out this live view: https://mensa.liste.party/