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

Class NormalizedLogLocalTermWeighter

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.LogLocalTermWeighter

gov.sandia.cognition.text.term.vector.weighter.local.NormalizedLogLocalTermWeighter

All Implemented Interfaces:

VectorFactoryContainer, LocalTermWeighter, CloneableSerializable, java.io.Serializable, java.lang.Cloneable

@PublicationReference(author={"Erica Chisholm","Tamara G. Kolda"},
                      title="New Term Weighting Formulas for the Vector Space Method in Information Retrieval",
                      type=TechnicalReport,
                      url="http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.40.3899",
                      year=1999,
                      notes="We use a slight modification of the formula for normalizing in this paper.")
public class NormalizedLogLocalTermWeighter
extends LogLocalTermWeighter

Implements a normalized version of the log local weighter. It is similar to the LogLocalWeighter except that it normalizes by the average frequency. It takes in a vector of term counts and for positive entries, it makes the weight log(1 + count) / log(1 + average) where average is the average count across the whole document. Counts of zero (or less) are weighted as zero.

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

Constructors

Constructor and Description
NormalizedLogLocalTermWeighter() Creates a new NormalizedLogLocalTermWeighter.
NormalizedLogLocalTermWeighter(VectorFactory<? extends Vector> vectorFactory) Creates a new NormalizedLogLocalTermWeighter

Method Summary

Modifier and Type	Method and Description
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

NormalizedLogLocalTermWeighter

public NormalizedLogLocalTermWeighter()

Creates a new NormalizedLogLocalTermWeighter.

NormalizedLogLocalTermWeighter

public NormalizedLogLocalTermWeighter(VectorFactory<? extends Vector> vectorFactory)

Creates a new NormalizedLogLocalTermWeighter

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.

Specified by:

computeLocalWeights in interface LocalTermWeighter

Overrides:

computeLocalWeights in class LogLocalTermWeighter

Parameters:

counts - The document to compute local weights for.

Returns:

The local weight vector for the documents.