info.debatty.java.stringsimilarity

Class NGram

java.lang.Object

info.debatty.java.stringsimilarity.NGram

All Implemented Interfaces:

NormalizedStringDistance, StringDistance, Serializable

@Immutable
public class NGram
extends Object
implements NormalizedStringDistance

N-Gram Similarity as defined by Kondrak, "N-Gram Similarity and Distance", String Processing and Information Retrieval, Lecture Notes in Computer Science Volume 3772, 2005, pp 115-126. The algorithm uses affixing with special character '\n' to increase the weight of first characters. The normalization is achieved by dividing the total similarity score the original length of the longest word. http://webdocs.cs.ualberta.ca/~kondrak/papers/spire05.pdf

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
NGram() Instantiate with default value for n-gram length (2).
NGram(int n) Instantiate with given value for n-gram length.

Method Summary

Modifier and Type	Method and Description
double	distance(String s0, String s1) Compute n-gram distance.

Methods inherited from class java.lang.Object

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

Constructor Detail

NGram

public NGram(int n)

Instantiate with given value for n-gram length.

Parameters:

n -

NGram

public NGram()

Instantiate with default value for n-gram length (2).

Method Detail

distance

public final double distance(String s0,
                             String s1)

Compute n-gram distance.

Specified by:

distance in interface StringDistance

Parameters:

s0 - The first string to compare.

s1 - The second string to compare.

Returns:

The computed n-gram distance in the range [0, 1]

Throws:

NullPointerException - if s0 or s1 is null.