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Command Line App

Lunch Roulette is a command line application that always requires a CSV file with staff "features", such as their team and specialty and start date. It is run using the ruby executable and specifying the staff via a CSV file:

ruby lib/lunch_roulette.rb data/staff.csv

Features are things like the team that a staffer is on, or the day they started. These features can be weighted in different ways and mapped so that some values are "closer" to others.

Along with specifying the various weights and mappings Lunch Roulette users, configurable options include the number of people per group, the number of iterations to perform, and the number of groups to output:

Usage: ruby lunch_roulette_generator.rb staff.csv [OPTIONS]
  -n, --min-group-size N           Minimum Lunch Group Size (default 4)
  -i, --iterations I               Number of Iterations (default 1,000)
  -m, --most-varied-sets M         Number of most varied sets to generate (default 1)
  -l, --least-varied-sets L        Number of least varied sets to generate (default 0)
  -v, --verbose                    Verbose output
  -d, --dont-write                 Don't write to files
  -h, --help                       Print this help

A Dummy Staff

So that you can run Lunch Roulette out of the box, I've provided a dummy staff (thanks to Namey for the hilariously fake names) dataset in data/staff.csv

Configuring Lunch Roulete

At the minimum, Lunch Roulette needs to know how different individual features are from each other. This is achieved by hardcoding a one dimensional mapping in config/mappings_and_weights.yml:

  Community Support: 100
  Community: 90
  Marketing: 80
  Communications: 70
  Operations: 50
  Product: 40
  Design: 30
  Engineering: 20
  Data: 0
  Backend: 0
  Data: 20
  Frontend: 30
  Mobile: 50
  Finance: 100
  Legal: 120
  table: 0.6
  days_here: 0.2
  team: 0.9
  specialty: 0.1
min_lunch_group_size: 4

Lunch Roulette expects all employees to have a team (Community, Design, etc.), and some employees to have a specialty (Data, Legal), etc.

Gut Testing Lunch Roulette

If specified, Lunch Roulette will output the top N results and/or the bottom N results. This is useful for testing its efficacy: if the bottom sets don't seem as great as the top sets, then you know its working! This will output 2 maximally varied sets, and two minimally varied sets:

ruby lib/lunch_roulette.rb -v -m 2 -l 2 data/staff.csv

If you wanted to get fancy, you could set up a double blind test of these results.

CSV Output

Unless instructed not to, Lunch Roulette will generate a new CSV in data/output each time it is run. The filenames are unique and based off MD5 hashes of the people in each group of the set. Lunch Roulette will also output a new staff CSV (prefixed staff_ in data/output) complete with new lunch IDs per-staff so that the next time it is run, it will avoid generating similar lunch groups. It is recommended that you overwrite data/staff.csv with whatever version you end up going with. If used with the verbose option, Lunch Roulette will dump a TSV list of staff with their new lunches so you can paste that back into Google Docs (pasting CSVs with commas doesn't seem to work).

Learn More & Math

Learn more about Lunch Roulette and the math behind it here:


Lunch Roulette is a command line tool for generating diverse lunch groups from a list of staff.







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