de.citec.scie.pdf

Class StringSimilarity

java.lang.Object

de.citec.scie.pdf.StringSimilarity

public class StringSimilarity
extends Object

This implements an algorithm to determine the similarity between Strings by utilizing an alignment/edit distance approach. In this special case of alignment the distance between numbers is regarded as zero while each mismatch otherwise is punished with 1 as is each deletion or insertion. The edit distance than is transformed to a similarity by taking 1-distance/(max{|a|,|b|}), which is 1 - the number of costly edit operations that had to be used relative to the worst case (replace the whole first sequence with the whole second sequence using only mismatches and elongate or shorten if necessary = max{|a|,|b|}). This can be interpreted as a confidence value that the two Strings represent the same content.

Author:

Benjamin Paassen - bpaassen(at)techfak.uni-bielefeld.de

Constructor Summary

Constructors

Constructor and Description
StringSimilarity()

Method Summary

Modifier and Type	Method and Description
double	calculate(String a, String b) This implements an algorithm to determine the similarity between Strings by utilizing an alignment/edit distance approach.

Methods inherited from class java.lang.Object

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

Constructor Detail

StringSimilarity

public StringSimilarity()

Method Detail

calculate

public double calculate(String a,
                        String b)

This implements an algorithm to determine the similarity between Strings by utilizing an alignment/edit distance approach. In this special case of alignment the distance between numbers is regarded as zero while each mismatch otherwise is punished with 1 as is each deletion or insertion. The edit distance than is transformed to a similarity by taking 1-distance/(max{|a|,|b|}), which is 1 - the number of costly edit operations that had to be used relative to the worst case (replace the whole first sequence with the whole second sequence using only mismatches and elongate or shorten if necessary = max{|a|,|b|}). This can be interpreted as a confidence value that the two Strings represent the same content.

Parameters:

a - the first string

b - the second string

Returns:

a confidence value (between 0 and 1) that the two Strings represent the same content