Descriptive Statistics

Overview

This gem adds methods to the Enumerable module to allow easy calculation of basic descriptive statistics for a set of data:

• Number - the sample size
• Sum
• Mean
• Median
• Mode
• Variance
• Standard Deviation
• Percentile - A method returning the value corresponding to the supplied percentile. For example, data.percentile(50) should equal data.median.
• Percentile Rank - calculates the percentile rank of a given input value within the set of data.
• Descriptive statistics - A method returning a hash with the above keys (as symbols). Percentile is represented as the first three quartes in the symbols q1, q2 and q3.

Examples

> require 'descriptive_statistics'
 => true 
> data = [2,6,9,3,5,1,8,3,6,9,2]
 => [2, 6, 9, 3, 5, 1, 8, 3, 6, 9, 2] 
> data.number
 => 11.0 
> data.sum
 => 54 
> data.mean
 => 4.909090909090909 
> data.median
 => 5.0 
> data.variance
 => 7.7190082644628095 
> data.standard_deviation
 => 2.778310325442932 
> data.percentile(70)
 => 6.0 
> data.percentile(70)
 => 6.0
> data.percentile_rank(8)
 => 72.727272
> data.descriptive_statistics
 => {:number=>11.0, 
  :sum=>54, 
  :variance=>7.7190082644628095, 
  :standard_deviation=>2.778310325442932, 
  :min=>1, 
  :max=>9, 
  :mean=>4.909090909090909, 
  :mode=>2, 
  :median=>5.0, 
  :range=>8, 
  :q1=>2.5, 
  :q2=>5.0, 
  :q3=>7.0}
> [4,2,3,1,4,5,6,8,0].mode
 => 4
> [17, 5, 3, 23, 33, 30, 45, 37].range
 => 42

Alternatively, you can use DescriptiveStatistics on individual objects, avoiding a global monkey patch.

> require 'descriptive_statistics/safe'
 => true
> data = [2,6,9,3,5,1,8,3,6,9,2]
 => [2, 6, 9, 3, 5, 1, 8, 3, 6, 9, 2] 
> data.extend(DescriptiveStatistics)
 => [2, 6, 9, 3, 5, 1, 8, 3, 6, 9, 2] 
> data.number
 => 11.0 
> data.sum
 => 54 

Ports

Javascript

Python

Go

Elixir

Clojure

License

Copyright (c) 2013 Derrick Parkhurst (derrick.parkhurst@gmail.com), Gregory Brown (gregory.t.brown@gmail.com), Daniel Farrell (danielfarrell76@gmail.com), Graham Malmgren, Guy Shechter

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.