daru

https://github.com/sciruby/daru

Ruby

Data Analysis in RUby

Daru::CategoricalIndex#at

Takes positional values and returns subset of the self
  capturing the categories at mentioned positions

Source | Google | Stack overflow

Edit

git clone [email protected]:sciruby/daru.git
cd daru
open lib/daru/index/categorical_index.rb

Contribute

# Make a new branch
git checkout -b -your-name--update-docs-Daru--CategoricalIndex-at-for-pr

# Commit to git
git add lib/daru/index/categorical_index.rbgit commit -m "better docs for Daru::CategoricalIndex#at"

# Open pull request
gem install hub # on a mac you can `brew install hub`
hub fork
git push <your name> -your-name--update-docs-Daru--CategoricalIndex-at-for-pr
hub pull-request

# Celebrate!