gov.sandia.cognition.text.term.vector.weighter.local
Class TermFrequencyLocalTermWeighter

java.lang.Object
  gov.sandia.cognition.util.AbstractCloneableSerializable
      gov.sandia.cognition.math.matrix.DefaultVectorFactoryContainer
          gov.sandia.cognition.text.term.vector.weighter.local.AbstractLocalTermWeighter
              gov.sandia.cognition.text.term.vector.weighter.local.TermFrequencyLocalTermWeighter

All Implemented Interfaces:

VectorFactoryContainer, LocalTermWeighter, CloneableSerializable, Serializable, Cloneable

@PublicationReference(author="Wikipedia",
                      title="tf-idf",
                      type=WebPage,
                      url="http://en.wikipedia.org/wiki/tf-idf",
                      year=2009)
public class TermFrequencyLocalTermWeighter
extends AbstractLocalTermWeighter

Local weighting for term frequency. The input is assumed to be a vector of the number of times a term appears in the document. If n_i,j is the number of times term i appears in document j, the term frequency for term i in document j is: tf_(i,j) = n_(i,j) / (sum_k n_(k, j)

Since:

3.0

Author:

Justin Basilico

See Also:

Serialized Form

Field Summary

Fields inherited from class gov.sandia.cognition.math.matrix.DefaultVectorFactoryContainer

vectorFactory

Constructor Summary

TermFrequencyLocalTermWeighter()
Creates a new TermFrequencyLocalTermWeighter.

TermFrequencyLocalTermWeighter(VectorFactory<? extends Vector> vectorFactory)
Creates a new LogLocalTermWeighter.

Method Summary

Vector

computeLocalWeights(Vector counts) Computes the new local weights for a given document.

Methods inherited from class gov.sandia.cognition.text.term.vector.weighter.local.AbstractLocalTermWeighter

computeLocalWeights

Methods inherited from class gov.sandia.cognition.math.matrix.DefaultVectorFactoryContainer

getVectorFactory, setVectorFactory

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

Methods inherited from interface gov.sandia.cognition.util.CloneableSerializable

clone

Constructor Detail

TermFrequencyLocalTermWeighter

public TermFrequencyLocalTermWeighter()

Creates a new TermFrequencyLocalTermWeighter.

TermFrequencyLocalTermWeighter

public TermFrequencyLocalTermWeighter(VectorFactory<? extends Vector> vectorFactory)

Creates a new LogLocalTermWeighter.

Parameters:

vectorFactory - The vector factory to use.

Method Detail

computeLocalWeights

public Vector computeLocalWeights(Vector counts)

Description copied from interface: LocalTermWeighter

Computes the new local weights for a given document.

Parameters:

counts - The document to compute local weights for.

Returns:

The local weight vector for the documents.