gov.sandia.cognition.text.term.vector

Class CosineSimilarityFunction

java.lang.Object

gov.sandia.cognition.util.AbstractCloneableSerializable

gov.sandia.cognition.text.term.vector.CosineSimilarityFunction

All Implemented Interfaces:

SimilarityFunction<Vectorizable,Vectorizable>, CloneableSerializable, java.io.Serializable, java.lang.Cloneable

public class CosineSimilarityFunction
extends AbstractCloneableSerializable
implements SimilarityFunction<Vectorizable,Vectorizable>

A vector cosine similarity function. The function is computed as: f(x, y) = (x * y) / (||x|| ||y||)

Since:

3.0

Author:

Justin Basilico

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
CosineSimilarityFunction() Creates a new CosineSimilarityFunction.

Method Summary

Modifier and Type	Method and Description
CosineDistanceMetric	asDivergence() Converts the similarity function into a divergence function.
double	evaluate(Vectorizable from, Vectorizable to) Evaluates the similarity between the two given objects.
static CosineSimilarityFunction	getInstance() Gets a singleton instance of the class.

Methods inherited from class gov.sandia.cognition.util.AbstractCloneableSerializable

clone

Methods inherited from class java.lang.Object

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

Constructor Detail

CosineSimilarityFunction

public CosineSimilarityFunction()

Creates a new CosineSimilarityFunction.

Method Detail

getInstance

public static CosineSimilarityFunction getInstance()

Gets a singleton instance of the class.

Returns:

A singleton instance of the class.

evaluate

public double evaluate(Vectorizable from,
                       Vectorizable to)

Description copied from interface: SimilarityFunction

Evaluates the similarity between the two given objects. Similarity between two objects is high if those objects are similar and low if they are not similar. Typically, this is a value that is greater than or equal to zero that is higher the more similar two objects are. If the two types are the same, then the rule f(x, y) = f(y, x) must apply.

Specified by:

evaluate in interface SimilarityFunction<Vectorizable,Vectorizable>

Parameters:

from - The object the similarity is from.

to - The object the similarity is to.

Returns:

The similarity between the two objects.

asDivergence

public CosineDistanceMetric asDivergence()

Description copied from interface: SimilarityFunction

Converts the similarity function into a divergence function. A diverge

Specified by:

asDivergence in interface SimilarityFunction<Vectorizable,Vectorizable>

Returns:

The divergence function version of this similarity function.