There's a lot of open issues
This library provides statistics features for Enumerable
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
 Project Readme

Enumerable::Statistics

Build Status

Enumerable::Statistics provides some methods to calculate statistical summary in arrays and enumerables.

Installation

Add this line to your application's Gemfile:

gem 'enumerable-statistics'

And then execute:

$ bundle

Or install it yourself as:

$ gem install enumerable-statistics

Usage

You should load this library by the following line in your script at first.

require 'enumerable/statistics'

The following methods are supplied by this library:

  • Array#mean, Enumerable#mean
    • Calculates a mean of values in an array or an enumerable
  • Array#variance, Enumerable#variance
    • Calculates a variance of values in an array or an enumerable
  • Array#stdev, Enumerable#stdev
    • Calculates a standard deviation of values in an array or an enumerable
  • Array#mean_variance, Enumerable#mean_variance
    • Calculates a mean and a variance simultaneously
  • Array#mean_stdev, Enumerable#mean_stdev
    • Calculates a mean and a standard deviation simultaneously
  • Array#median
    • Calculates a median of values in an array
  • Array#percentile(q)
    • Calculates a percentile or percentiles of values in an array
  • Array#value_counts, Enumerable#value_counts, and Hash#value_counts
    • Count how many items for each value in the container
  • Array#histogram
    • Calculate histogram of the values in the array

Moreover, for Ruby < 2.4, Array#sum and Enumerable#sum are provided.

All methods scan a collection once to calculate statistics and preserve precision as possible.

Performance

$ bundle exec rake bench
# sum
Warming up --------------------------------------
              inject     1.545k i/100ms
               while     2.342k i/100ms
                 sum    11.009k i/100ms
Calculating -------------------------------------
              inject     15.016k (± 9.6%) i/s -     75.705k in   5.098723s
               while     22.238k (±16.2%) i/s -    107.732k in   5.068156s
                 sum    112.992k (± 6.9%) i/s -    572.468k in   5.091868s
# mean
Warming up --------------------------------------
              inject     1.578k i/100ms
               while     2.057k i/100ms
                mean     9.855k i/100ms
Calculating -------------------------------------
              inject     15.347k (± 8.6%) i/s -     77.322k in   5.076009s
               while     21.669k (±14.5%) i/s -    106.964k in   5.074312s
                mean    108.861k (± 8.9%) i/s -    542.025k in   5.021786s
# variance
Warming up --------------------------------------
              inject   586.000  i/100ms
               while   826.000  i/100ms
            variance     8.475k i/100ms
Calculating -------------------------------------
              inject      6.187k (± 6.7%) i/s -     31.058k in   5.043418s
               while      8.597k (± 7.4%) i/s -     42.952k in   5.024587s
            variance     84.702k (± 8.5%) i/s -    423.750k in   5.039936s

Development

After checking out the repo, run bin/setup to install dependencies. You can also run bin/console for an interactive prompt that will allow you to experiment.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and tags, and push the .gem file to rubygems.org.

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/mrkn/enumerable-statistics.