path: root/readme.md

#stringmetric [![Build Status](https://travis-ci.org/rockymadden/stringmetric.png?branch=master)](http://travis-ci.org/rockymadden/stringmetric)
String metrics and phonetic algorithms implemented in Scala. The library provides facilities to perform approximate string matching, measurement of string similarity/distance, indexing by word pronunciation, and sounds-like comparisions. In addition to the core library, each metric and algorithm has a command line interface. Heavy emphasis is placed on unit testing and performance (verified via microbenchmark suites).

## Metrics and Algorithms
* __[Dice / Sorensen](http://en.wikipedia.org/wiki/Dice%27s_coefficient)__ (Similarity metric)
* __[Hamming](http://en.wikipedia.org/wiki/Hamming_distance)__ (Similarity metric)
* __[Jaro](http://en.wikipedia.org/wiki/Jaro-Winkler_distance)__ (Similarity metric)
* __[Jaro-Winkler](http://en.wikipedia.org/wiki/Jaro-Winkler_distance)__ (Similarity metric)
* __[Levenshtein](http://en.wikipedia.org/wiki/Levenshtein_distance)__ (Similarity metric)
* __[Metaphone](http://en.wikipedia.org/wiki/Metaphone)__ (Phonetic metric and algorithm)
* __[N-Gram](http://en.wikipedia.org/wiki/N-gram)__ (Similarity metric and algorithm)
* __[NYSIIS](http://en.wikipedia.org/wiki/New_York_State_Identification_and_Intelligence_System)__ (Phonetic metric and algorithm)
* __[Ratcliff / Obershelp](http://xlinux.nist.gov/dads/HTML/ratcliffObershelp.html)__ (Similarity metric)
* __[Refined NYSIIS](http://www.markcrocker.com/rexxtipsntricks/rxtt28.2.0482.html)__ (Phonetic metric and algorithm)
* __[Refined Soundex](http://ntz-develop.blogspot.com/2011/03/phonetic-algorithms.html)__ (Phonetic metric and algorithm)
* __[Soundex](http://en.wikipedia.org/wiki/Soundex)__ (Phonetic metric and algorithm)
* __Weighted Levenshtein__ (Similarity metric)

## Similarity package
Useful for approximate string matching and measurement of string distance. Most metrics calculate the similarity of two strings as a double with a value between 0 and 1. A value of 0 being completely different and a value of 1 being completely similar.

__Dice / Sorensen Metric:__
```scala
println(DiceSorensenMetric.compare("night", "nacht"))
println(DiceSorensenMetric.compare("context", "contact")
```

Output:
```shell
0.6
0.7142857142857143
```

__Hamming Metric:__
```scala
println(HammingMetric.compare("toned", "roses"))
println(HammingMetric.compare("1011101", "1001001")
```

Output:
```shell
3
2
```

## Testing
```shell
$ gradle :stringmetric-core:test
```

```shell
$ gradle :stringmetric-cli:test
```

## Building
```shell
$ gradle :stringmetric-core:jar
```

```shell
$ gradle :stringmetric-cli:tar
```

## Depending Upon
Available on the [Maven Central Repository](http://search.maven.org/#search%7Cga%7C1%7Cg%3A%22com.rockymadden.stringmetric%22):

* __groupId__: com.rockymadden.stringmetric
* __artifactId__: stringmetric-core
* __artifactId__: stringmetric-cli

## Requirements
* Scala 2.10.x
* Gradle 1.x

## Versioning
[Semantic Versioning v2.0](http://semver.org/)

## License
[Apache License v2.0](http://www.apache.org/licenses/LICENSE-2.0)

## Todo
* SmithWaterman
* MongeElkan
* NeedlemanWunch
* Jaccard
* Double Metaphone
* Memoization decorator

## Questions and Comments
Reach me at <stringmetric@rockymadden.com>.