wilson_interval

Calculate Wilson confidence intervals with minimum fuss.

You always need to specify :total and :confidence. You also need to specify either :p_hat or :successes. The :confidence option is optional and defaults to 0.95.

wilson = Wilson::Interval.new(p_hat: 0.5, total: 1000, confidence: 0.95)
wilson.lower_bound.round(4) => 0.4691
wilson.upper_bound.round(4) => 0.5309

wilson = Wilson::Interval.new(successes: 500, total: 1000, confidence: 0.95)
wilson.lower_bound.round(4) => 0.4691
wilson.upper_bound.round(4) => 0.5309

Based on code found at evanmiller.org. Adapted according to Wikipedia.

• Check out the latest master to make sure the feature hasn't been implemented or the bug hasn't been fixed yet.
• Check out the issue tracker to make sure someone already hasn't requested it and/or contributed it.
• Fork the project.
• Start a feature/bugfix branch.
• Commit and push until you are happy with your contribution.
• Make sure to add tests for it. This is important so I don't break it in a future version unintentionally.
• Please try not to mess with the Rakefile, version, or history. If you want to have your own version, or is otherwise necessary, that is fine, but please isolate to its own commit so I can cherry-pick around it.

Copyright (c) 2013 Magnus von Koeller. Licensed under the MIT license. See LICENSE.txt for further details.