Contents

# Zipfian

[Zipfian distribution](http://en.wikipedia.org/wiki/Zipf's_law) implementation.

## Installation

Add this line to your application's Gemfile:

    gem 'zipfian'

And then execute:

    $ bundle

Or install it yourself as:

    $ gem install zipfian

## Usage

```ruby
# 1000: Number of elements
#  1.0: Exponent
z = Zipfian.new 1000, 1.0

puts z.n    # 1000
puts z.s    # 0.1

(1..1000).each do |i|
  puts [z.pmf(i), z.cdf(i)].join ' - '
end

puts z.sample    # Integer between 1 and 1000

```

## Disclaimer

On initialization, Zipfian precalculates and stores the values of cumulative distribution function for every integer in the range.
As the number gets bigger, it will take more time and memory.

```ruby
# A workaround of memory limitation
z = Zipfian.new 1000000, 0.5

puts z.sample * 1000 - rand(1000)
```

## Contributing

1. Fork it
2. Create your feature branch (`git checkout -b my-new-feature`)
3. Commit your changes (`git commit -am 'Added some feature'`)
4. Push to the branch (`git push origin my-new-feature`)
5. Create new Pull Request

Version data entries

1 entries across 1 versions & 1 rubygems

Version	Path
zipfian-0.0.2	README.md