Package org.apache.commons.text.similarity

# Class JaroWinklerSimilarity

java.lang.Object
org.apache.commons.text.similarity.JaroWinklerSimilarity

All Implemented Interfaces:
  `SimilarityScore<Double>`

public class JaroWinklerSimilarity extends Object implements SimilarityScore<Double>
A similarity algorithm indicating the percentage of matched characters between two character sequences.

The Jaro measure is the weighted sum of percentage of matched characters from each file and transposed characters. Winkler increased this measure for matching initial characters.

This implementation is based on the Jaro Winkler similarity algorithm from https://en.wikipedia.org/wiki/Jaro%E2%80%93Winkler_distance.

This code has been adapted from Apache Commons Lang 3.3.

Since:
  1.7

- ## Constructor Summary

  Constructors
  Constructor
  Description
  `JaroWinklerSimilarity()`

- ## Method Summary

  Modifier and Type
  Method
  Description
  `Double`
  `apply(CharSequence left, CharSequence right)`
  Computes the Jaro Winkler Similarity between two character sequences.
  `protected static int[]`
  `matches(CharSequence first, CharSequence second)`
  This method returns the Jaro-Winkler string matches, half transpositions, prefix array.

  ### Methods inherited from class java.lang.Object

  `clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

- ## Constructor Details

  - ### JaroWinklerSimilarity

    public JaroWinklerSimilarity()

- ## Method Details

  - ### matches

    protected static int[] matches(CharSequence first, CharSequence second)
    This method returns the Jaro-Winkler string matches, half transpositions, prefix array.
    Parameters:
      `first` - the first string to be matched
      `second` - the second string to be matched
    Returns:
      mtp array containing: matches, half transpositions, and prefix

  - ### apply

    public Double apply(CharSequence left, CharSequence right)
    Computes the Jaro Winkler Similarity between two character sequences.

         sim.apply(null, null)          = IllegalArgumentException
         sim.apply("foo", null)         = IllegalArgumentException
         sim.apply(null, "foo")         = IllegalArgumentException
         sim.apply("", "")              = 1.0
         sim.apply("foo", "foo")        = 1.0
         sim.apply("foo", "foo ")       = 0.94
         sim.apply("foo", "foo  ")      = 0.91
         sim.apply("foo", " foo ")      = 0.87
         sim.apply("foo", "  foo")      = 0.51
         sim.apply("", "a")             = 0.0
         sim.apply("aaapppp", "")       = 0.0
         sim.apply("frog", "fog")       = 0.93
         sim.apply("fly", "ant")        = 0.0
         sim.apply("elephant", "hippo") = 0.44
         sim.apply("hippo", "elephant") = 0.44
         sim.apply("hippo", "zzzzzzzz") = 0.0
         sim.apply("hello", "hallo")    = 0.88
         sim.apply("ABC Corporation", "ABC Corp") = 0.91
         sim.apply("D N H Enterprises Inc", "D & H Enterprises, Inc.") = 0.95
         sim.apply("My Gym Children's Fitness Center", "My Gym. Childrens Fitness") = 0.92
         sim.apply("PENNSYLVANIA", "PENNCISYLVNIA") = 0.88

    Specified by:
      `apply` in interface `SimilarityScore<Double>`
    Parameters:
      `left` - the first CharSequence, must not be null
      `right` - the second CharSequence, must not be null
    Returns:
      result similarity
    Throws:
      `IllegalArgumentException` - if either CharSequence input is `null`