info.debatty.java.stringsimilarity

Class Levenshtein

java.lang.Object

info.debatty.java.stringsimilarity.Levenshtein

All Implemented Interfaces:

StringSimilarityInterface

public class Levenshtein
extends Object
implements StringSimilarityInterface

The Levenshtein distance between two words is the minimum number of single-character edits (insertions, deletions or substitutions) required to change one word into the other.

Author:

Thibault Debatty

Constructor Summary

Constructors

Constructor and Description
Levenshtein()

Method Summary

Methods

Modifier and Type	Method and Description
double	distance(String s1, String s2) Generally, distance = 1 - similarity.
static int	Distance(String s1, String s2)
int	distanceAbsolute(String s1, String s2) The Levenshtein distance, or edit distance, between two words is the minimum number of single-character edits (insertions, deletions or substitutions) required to change one word into the other.
static void	main(String[] args)
double	similarity(String s1, String s2)

Methods inherited from class java.lang.Object

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

Constructor Detail

Levenshtein

public Levenshtein()

Method Detail

main

public static void main(String[] args)

Distance

public static int Distance(String s1,
           String s2)

distance

public double distance(String s1,
              String s2)

Description copied from interface: StringSimilarityInterface

Generally, distance = 1 - similarity. Some implementations can also provide a method distanceAbsolute

Specified by:

distance in interface StringSimilarityInterface

Returns:

distance between 0 (s1 = s2) and 1 (completely different)

similarity

public double similarity(String s1,
                String s2)

Specified by:

similarity in interface StringSimilarityInterface

Returns:

similarity between 0 (completely different) and 1 (s1 = s2)

distanceAbsolute

public int distanceAbsolute(String s1,
                   String s2)

The Levenshtein distance, or edit distance, between two words is the minimum number of single-character edits (insertions, deletions or substitutions) required to change one word into the other. http://en.wikipedia.org/wiki/Levenshtein_distance It is always at least the difference of the sizes of the two strings. It is at most the length of the longer string. It is zero if and only if the strings are equal. If the strings are the same size, the Hamming distance is an upper bound on the Levenshtein distance. The Levenshtein distance verifies the triangle inequality (the distance between two strings is no greater than the sum Levenshtein distances from a third string). Implementation uses dynamic programming (Wagner–Fischer algorithm), with only 2 rows of data. The space requirement is thus O(m) and the algorithm runs in O(mn).

Parameters:

s1 -

s2 -

Returns: