resemblance

Returns the percentage of resemblance (likeness, similarity) between two strings / objects

Downloads in past

Stats

StarsIssuesVersionUpdatedCreatedSize
resemblance
401.0.07 years ago8 years agoMinified + gzip package size for resemblance in KB

Readme

Resemblance
This package contains functions to get the percentage of resemblance (likeness, similarity) between two strings or two objects.
The algorithm used is actually quite simple : it does a case-insensitive levenshtein distance, and also ignores non-alphanumerical characters (such as spaces, dashes, dots, etc).
Quick jump to examples :

Simple string resemblance

Object resemblance

Get similar objects from a set

How to use ?

The package contains 3 functions :
var resemblance = require('resemblance');
// this modules has 3 functions :
// resemblance.compareStrings(a, b)
// resemblance.compareObjects(a, b, weights)
// resemblance.getSimilar(obj, set, threshold, weights)

Examples

Simple string comparison (percentage of resemblance)

// the following two strings are a perfect match
// 100% resemblance :
resemblance.compareStrings('Saint-Étienne', 'SAINT ETIENNE');
// 90% resemblance :
resemblance.compareStrings('0123456789', '123456789');
// 50% resemblance :
resemblance.compareStrings('abc def', 'abc xyz');
// 0% resemblance :
resemblance.compareStrings('Hello World', '');

Object comparison (percentage of resemblance)

// 100% resemblance :
var a = { name: 'David' };
var b = { name: 'David' };
var weights = { name: 100 };
resemblance.compareObjects(a, b, weights);
// 67% resemblance :
resemblance.compareObjects(
  { a: 'a', b: 'b', c: 'c' },
  { a: 'a', b: 'c', c: 'b' },
  { a: 67, b: 33, c: 0 }
);
// a is 100% similar,
// b is 100% different,
// c does not matter (weight = 0)

Get similar objects from a set

In this example, we would like to find similar address objects. the set parameter can be fetched from a database, for example.
// object to compare
var address = {
  num: '17',
  way: 'Boulevard Antoine de Saint-Exupéry',
  zip: '69009',
  city: 'Lyon',
  country: 'France'
};

// object set
var addresses = [
  {
    num: '17',
    way: 'BOULEVARD SAINT EXUPERY',
    zip: '69009',
    city: 'LYON',
    country: 'FR',
    geoloc: {
      lat: 45,
      lon: 119
    }
  },
  {
    num: '17',
    way: 'Rue Antoine de Saint-Exupéry',
    zip: '69140',
    city: 'Rillieux-la-Pape',
    country: 'France'
  }
];

// weights of each properties
// note that property names can be deeper than one
// level for example, we could put some weight on
// the 'geoloc.lat' property
var weights = {
  num: 20,
  way: 35,
  zip: 15,
  city: 20,
  country: 10,
  geoloc: 0
};

// get addresses that are more than 50% similar
resemblance.getSimilar(obj, set, weights, 0.5)

// returns :
[
  {
    resemblance: 0.8283333333333333,
    obj: {
      num: '17',
      way: 'BOULEVARD SAINT EXUPERY',
      zip: '69009',
      city: 'LYON',
      country: 'FR',
      geoloc: {
        lat: 45,
        lon: 119
      }
    }
  },
  {
    resemblance: 0.6426190476190476,
    obj: {
      num: '17',
      way: 'Rue Antoine de Saint-Exupéry',
      zip: '69140',
      city: 'Rillieux-la-Pape',
      country: 'France'
    }
  }
]