String Metric

A library implementing different string similarity and distance measures, and Implement by TypeScript. Also, you can use in JavaScript.

Algorithm reference java-string-similarity

Install

npm install string-metric

Progress

Algorithm	Complete?
Jaro-Winkler	Yes
Levenshtein	Yes
Normalized-Levenshtein	Yes
Weighted-Levenshtein	Yes
Damerau	Yes
Optimal-String-Alignment	Yes
Longest-Common-Subsequence	Yes
Metric-Longest-Common-Subsequence	Yes
N-Gram	Yes
Q-Gram	No
Shingle (n-gram) based algorithms	No
Cosine similarity	No
Jaccard index	No
Sorensen-Dice coefficient	No
Ratcliff-Obershelp	No

Jaro-Winkler

For more specs, please go to tests/JaroWinkler.spec.ts in the repository.

const instance = new JaroWinkler();

const s1 = 'My string';
const s2 = 'My string';
instance.similarity(s1, s2); // 1

const s1 = 'My string';
const s2 = 'My tsring';
instance.similarity(s1, s2); // 0.974074

const s1 = 'My string';
const s2 = 'My ntrisg';
instance.similarity(s1, s2); // 0.896296

Levenshtein

For more specs, please go to tests/Levenshtein.spec.ts in the repository.

const instance = new Levenshtein();

const s1 = 'My string';
const s2 = 'My string';
instance.distance(s1, s2); // 0

const s1 = 'My string';
const s2 = 'My tring';
instance.distance(s1, s2); // 1

const s1 = 'My string';
const s2 = 'M string2';
instance.distance(s1, s2); // 2

Normalized-Levenshtein

For more specs, please go to tests/NormalizedLevenshtein.spec.ts in the repository.

const instance = new NormalizedLevenshtein();

Weighted-Levenshtein

For more specs, please go to tests/WeightedLevenshtein.spec.ts in the repository.

const instance = new WeightedLevenshtein();

Damerau

For more specs, please go to tests/Damerau.spec.ts in the repository.

const instance = new Damerau();

const s1 = 'ABCDEF';
const s2 = 'ABDCEF';
instance.distance(s1, s2); // 1

const s1 = 'ABCDEF';
const s2 = 'BACDFE';
instance.distance(s1, s2); // 2

const s1 = 'ABCDEF';
const s2 = 'ABCDE';
instance.distance(s1, s2); // 1

Optimal-String-Alignment

For more specs, please go to tests/OptimalStringAlignment.spec.ts in the repository.

const instance = new OptimalStringAlignment();

const s1 = 'ABDCEF';
const s2 = 'ADCEF';
instance.distance(s1, s2); // 1

const s1 = 'BAC';
const s2 = 'CAB';
instance.distance(s1, s2); // 2

const s1 = 'CA';
const s2 = 'ABC';
instance.distance(s1, s2); // 3

Longest-Common-Subsequence

For more specs, please go to tests/LongestCommonSubsequence.spec.ts in the repository.

const instance = new LongestCommonSubsequence();

const s1 = 'AGCAT';
const s2 = 'GAC';
instance.distance(s1, s2); // 4

const s1 = 'AGCAT';
const s2 = 'AGCT';
instance.distance(s1, s2); // 1

Metric-Longest-Common-Subsequence

For more specs, please go to tests/MetricLCS.spec.ts in the repository.

const instance = new MetricLCS();

N-Gram

For more specs, please go to tests/NGram.spec.ts in the repository.

const instance = new NGram();

const s1 = 'SIJK';
const s2 = 'SIJK';
instance.distance(s1, s2); // 0

const s0 = 'ABABABAB';
const s1 = 'ABCABCABCABC';
const s2 = 'POIULKJH';
instance.distance(s0, s1) < instance.distance(s0, s2); // true