#stringmetric [![Build Status](https://travis-ci.org/rockymadden/stringmetric.png?branch=master)](http://travis-ci.org/rockymadden/stringmetric) String metrics and phonetic algorithms for Scala. The library provides facilities to perform approximate string matching, measurement of string similarity/distance, indexing by word pronunciation, and sounds-like comparisons. In addition to the core library, each metric and algorithm has a command line interface. * __Requirements:__ Scala 2.10+ * __Documentation:__ [Scaladoc](http://rockymadden.com/stringmetric/scaladoc/) * __Issues:__ [Enhancements](https://github.com/rockymadden/stringmetric/issues?labels=accepted%2Cenhancement&page=1&state=open), [Questions](https://github.com/rockymadden/stringmetric/issues?labels=accepted%2Cquestion&page=1&state=open), [Bugs](https://github.com/rockymadden/stringmetric/issues?labels=accepted%2Cbug&page=1&state=open) * __Versioning:__ [Semantic Versioning v2.0](http://semver.org/) ## Metrics and algorithms * __[Dice / Sorensen](http://en.wikipedia.org/wiki/Dice%27s_coefficient)__ (Similarity metric) * __[Double Metaphone](http://en.wikipedia.org/wiki/Metaphone)__ ([Queued](https://github.com/rockymadden/stringmetric/issues/6) phonetic metric and algorithm) * __[Hamming](http://en.wikipedia.org/wiki/Hamming_distance)__ (Similarity metric) * __[Jaccard](http://en.wikipedia.org/wiki/Jaccard_index)__ (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) * __[Monge-Elkan](http://www.cs.cmu.edu/~pradeepr/papers/ijcai03.pdf)__ ([Queued](https://github.com/rockymadden/stringmetric/issues/7) similarity metric) * __[Match Rating Approach](http://en.wikipedia.org/wiki/Match_rating_approach)__ ([Queued](https://github.com/rockymadden/stringmetric/issues/8) phonetic metric and algorithm) * __[Needleman-Wunch](http://en.wikipedia.org/wiki/Needleman%E2%80%93Wunsch_algorithm)__ ([Queued](https://github.com/rockymadden/stringmetric/issues/9) similarity metric) * __[N-Gram](http://en.wikipedia.org/wiki/N-gram)__ (Similarity metric) * __[NYSIIS](http://en.wikipedia.org/wiki/New_York_State_Identification_and_Intelligence_System)__ (Phonetic metric and algorithm) * __[Overlap](http://en.wikipedia.org/wiki/Overlap_coefficient)__ (Similarity metric) * __[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) * __[Tanimoto](http://en.wikipedia.org/wiki/Tanimoto_coefficient)__ ([Queued](https://github.com/rockymadden/stringmetric/issues/10) similarity metric) * __[Tversky](http://en.wikipedia.org/wiki/Tversky_index)__ ([Queued](https://github.com/rockymadden/stringmetric/issues/16) similarity metric) * __[Smith-Waterman](http://en.wikipedia.org/wiki/Smith%E2%80%93Waterman_algorithm)__ ([Queued](https://github.com/rockymadden/stringmetric/issues/11) similarity metric) * __[Soundex](http://en.wikipedia.org/wiki/Soundex)__ (Phonetic metric and algorithm) * __Weighted Levenshtein__ (Similarity metric) ## Depending upon __SBT:__ ```scala libraryDependencies += "com.rockymadden.stringmetric" %% "stringmetric-core" % "0.27.4" ``` --- __Gradle:__ ```groovy compile 'com.rockymadden.stringmetric:stringmetric-core_2.10:0.27.4' ``` --- __Maven:__ ```xml com.rockymadden.stringmetric stringmetric-core_2.10 0.27.4 ``` --- ## 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 DiceSorensenMetric(1).compare("night", "nacht") // 0.6 DiceSorensenMetric(1).compare("context", "contact") // 0.7142857142857143 ``` Note you must specify the size of the n-gram you wish to use. --- __Hamming Metric:__ ```scala HammingMetric.compare("toned", "roses") // 3 HammingMetric.compare("1011101", "1001001") // 2 ``` Note the exception of integers, rather than doubles, being returned. --- __Jaccard Metric:__ ```scala JaccardMetric(1).compare("night", "nacht") // 0.3 JaccardMetric(1).compare("context", "contact") // 0.35714285714285715 ``` Note you must specify the size of the n-gram you wish to use. --- __Jaro Metric:__ ```scala JaroMetric.compare("dwayne", "duane") // 0.8222222222222223 JaroMetric.compare("jones", "johnson") // 0.7904761904761904 JaroMetric.compare("fvie", "ten") // 0.0 ``` --- __Jaro-Winkler Metric:__ ```scala JaroWinklerMetric.compare("dwayne", "duane") // 0.8400000000000001 JaroWinklerMetric.compare("jones", "johnson") // 0.8323809523809523 JaroWinklerMetric.compare("fvie", "ten") // 0.0 ``` --- __Levenshtein Metric:__ ```scala LevenshteinMetric.compare("sitting", "kitten") // 3 LevenshteinMetric.compare("cake", "drake") // 2 ``` Note the exception of integers, rather than doubles, being returned. --- __N-Gram Metric:__ ```scala NGramMetric(1).compare("night", "nacht") // 0.6 NGramMetric(2).compare("night", "nacht") // 0.25 NGramMetric(2).compare("context", "contact") // 0.5 ``` Note you must specify the size of the n-gram you wish to use. --- __Overlap Metric:__ ```scala OverlapMetric(1).compare("night", "nacht") // 0.6 OverlapMetric(1).compare("context", "contact") // 0.7142857142857143 ``` Note you must specify the size of the n-gram you wish to use. --- __Ratcliff/Obershelp Metric:__ ```scala RatcliffObershelpMetric.compare("aleksander", "alexandre") // 0.7368421052631579 RatcliffObershelpMetric.compare("pennsylvania", "pencilvaneya") // 0.6666666666666666 ``` --- __Weighted Levenshtein Metric:__ ```scala WeightedLevenshteinMetric(10, 0.1, 1).compare("book", "back") // 2 WeightedLevenshteinMetric(10, 0.1, 1).compare("hosp", "hospital") // 0.4 WeightedLevenshteinMetric(10, 0.1, 1).compare("hospital", "hosp") // 40 ``` Note you must specify the weight of each operation. Delete, insert, and then substitute. Note that while a double is returned, it can be outside the range of 0 to 1, based upon the weights used. --- ## Phonetic package Useful for indexing by word pronunciation and performing sounds-like comparisons. All metrics return a boolean value indicating if the two strings sound the same, per the algorithm used. All metrics have an algorithm counterpart which provide the means to perform indexing by word pronunciation. --- __Metaphone Metric:__ ```scala MetaphoneMetric.compare("merci", "mercy") // true MetaphoneMetric.compare("dumb", "gum") // false ``` --- __Metaphone Algorithm:__ ```scala MetaphoneAlgorithm.compute("dumb") // tm MetaphoneAlgorithm.compute("knuth") // n0 ``` --- __NYSIIS Metric:__ ```scala NysiisMetric.compare("ham", "hum") // true NysiisMetric.compare("dumb", "gum") // false ``` --- __NYSIIS Algorithm:__ ```scala NysiisAlgorithm.compute("macintosh") // mcant NysiisAlgorithm.compute("knuth") // nnat ``` --- __Refined NYSIIS Metric:__ ```scala RefinedNysiisMetric.compare("ham", "hum") // true RefinedNysiisMetric.compare("dumb", "gum") // false ``` --- __Refined NYSIIS Algorithm:__ ```scala RefinedNysiisAlgorithm.compute("macintosh") // mcantas RefinedNysiisAlgorithm.compute("westerlund") // wastarlad ``` --- __Refined Soundex Metric:__ ```scala RefinedSoundexMetric.compare("robert", "rupert") // true RefinedSoundexMetric.compare("robert", "rubin") // false ``` --- __Refined Soundex Algorithm:__ ```scala RefinedSoundexAlgorithm.compute("hairs") // h093 RefinedSoundexAlgorithm.compute("lambert") // l7081096 ``` --- __Soundex Metric:__ ```scala SoundexMetric.compare("robert", "rupert") // true SoundexMetric.compare("robert", "rubin") // false ``` --- __Soundex Algorithm:__ ```scala SoundexAlgorithm.compute("rupert") // r163 SoundexAlgorithm.compute("lukasiewicz") // l222 ``` --- ## Convenience objects __StringAlgorithm:__ ```scala StringAlgorithm.computeWithMetaphone("abcdef") StringAlgorithm.computeWithNysiis("abcdef") ``` --- __StringMetric:__ ```scala StringMetric.compareWithJaccard(1)("abcdef", "abcxyz") StringMetric.compareWithJaroWinkler("abcdef", "abcxyz") ``` --- ## Decorating It is possible to decorate algorithms and metrics with additional functionality, which you can mix and match. Decorations include: * __[withMemoization](https://en.wikipedia.org/wiki/Memoization):__ Computations and comparisons are cached. Future calls made with identical arguments will be looked up, rather than computed. * __withTransform:__ Transform arguments prior to computation/comparison. A handful of pre-built transforms are located in the [transform module](https://github.com/rockymadden/stringmetric/blob/master/core/src/main/scala/com/rockymadden/stringmetric/transform.scala). --- Non-decorated: ```scala MetaphoneAlgorithm.compute("abcdef") MetaphoneMetric.compare("abcdef", "abcxyz") ``` --- Using memoization: ```scala (MetaphoneAlgorithm withMemoization).compute("abcdef") ``` --- Using a transform so that we only examine alphabetical characters: ```scala (MetaphoneAlgorithm withTransform filterAlpha).compute("abcdef") (MetaphoneMetric withTransform filterAlpha).compare("abcdef", "abcxyz") ``` --- Using a functionally composed transform so that we only examine alphabetical characters, but the case will not matter: ```scala val composedTransform = (filterAlpha andThen ignoreAlphaCase) (MetaphoneAlgorithm withTransform composedTransform).compute("abcdef") (MetaphoneMetric withTransform composedTransform).compare("abcdef", "abcxyz") ``` --- Making your own transform: ```scala val myTransform: StringTransform = (ca) => ca.filter(_ == 'x') (MetaphoneAlgorithm withTransform myTransform).compute("abcdef") (MetaphoneMetric withTransform myTransform).compare("abcdef", "abcxyz") ``` --- Using memoization and a transform: ```scala ((MetaphoneAlgorithm withMemoization) withTransform filterAlpha).compute("abcdef") ``` --- ## Building the CLIs ```shell $ git clone https://github.com/rockymadden/stringmetric.git $ cd stringmetric $ sbt clean package $ ./project/build.sh $ ./target/cli/jarometric abc xyz ``` --- ## Using the CLIs Get help: ```shell $ metaphonemetric --help Compares two strings to determine if they are phonetically similarly, per the Metaphone algorithm. Syntax: metaphonemetric [Options] string1 string2... Options: -h, --help Outputs description, syntax, and options. ``` --- Get comparison value with metrics: ```shell $ jarowinklermetric dog dawg 0.75 ``` --- Get representation value with phonetic algorithms: ```shell $ metaphonealgorithm dog tk ``` --- ## License ``` The MIT License (MIT) Copyright (c) 2013 Rocky Madden (http://rockymadden.com/) 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. ```