Package org.apache.commons.text.similarity

Class JaroWinklerDistance

java.lang.Object

org.apache.commons.text.similarity.JaroWinklerDistance

All Implemented Interfaces:

SimilarityScore<Double>

public class JaroWinklerDistance
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 http://en.wikipedia.org/wiki/Jaro%E2%80%93Winkler_distance.

This code has been adapted from Apache Commons Lang 3.3.

Since:

1.0

Field Summary

Fields

Modifier and Type	Field	Description
static int	INDEX_NOT_FOUND	Represents a failed index search.

Constructor Summary

Constructors

Constructor	Description
JaroWinklerDistance()

Method Summary

Modifier and Type	Method	Description
Double	apply(CharSequence left, CharSequence right)	Find the Jaro Winkler Distance which indicates the similarity score between two CharSequences.
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

Field Detail

INDEX_NOT_FOUND

public static final int INDEX_NOT_FOUND

Represents a failed index search.

See Also:

Constant Field Values

Constructor Detail

JaroWinklerDistance

public JaroWinklerDistance()

Method Detail

apply

public Double apply(CharSequence left,
                    CharSequence right)

Find the Jaro Winkler Distance which indicates the similarity score between two CharSequences.

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

Throws:

IllegalArgumentException - if either CharSequence input is null

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