Enumerable::Statistics provides some methods to calculate statistical summary in arrays and enumerables.
Add this line to your application's Gemfile:
gem 'enumerable-statistics'
And then execute:
$ bundle
Or install it yourself as:
$ gem install enumerable-statistics
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
, andHash#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.
$ 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
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.
Bug reports and pull requests are welcome on GitHub at https://github.com/mrkn/enumerable-statistics.