cadmium_string_distance

Corundum provides an implimentation of two different string distance algorithms, the Jaro-Winkler Distance Algorithm and the Levenshtein Distance Algorithm.

Installation

1. Add the dependency to your shard.yml:

   dependencies:
     cadmium_distance:
       github: cadmiumcr/distance

2. Run shards install

Usage

require "cadmium_distance"

Jaro-Winkler

The Jaro-Winkler algorithm returns a number between 0 and 1 which tells how closely two strings match (1 being perfect and 0 being not at all).

jwd = Cadmium::Distance::JaroWinkler.new

jwd.distance("dixon","dicksonx")
# => 0.8133333333333332

jwd.distance("same","same")
# => 1

jwd.distance("not","same")
# => 0.0

Levenshtein

The Levenshtein distance algorithm returns the number of edits (insertions, modifications, or deletions) required to transform one string into another.

Cadmium::Distance::Levenshtein.distance("doctor", "doktor")
# => 1

Cadmium::Distance::Levenshtein.distance("doctor", "doctor")
# => 0

Cadmium::Distance::Levenshtein.distance("flad", "flaten")
# => 3

Pair

Pair Distance uses arbitrary n-grams to calculate how similar one string is to another. By calculating the bi-grams for a string, the pair distance algorithm first checks how many occurrences of each bi-gram occur in both strings, then it calculates their similarity with the formula simularity = (2 · intersections) / (s1size + s2size).

Cadmium::Distance::Pair.distance("night", "nacht")
# => 0.25

Contributing

1. Fork it (https://github.com/cadmiumcr/distance/fork)
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create a new Pull Request

Contributors

• Chris Watson - creator and maintainer