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

Class LogLocalTermWeighter

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

All Implemented Interfaces:

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

Direct Known Subclasses:

NormalizedLogLocalTermWeighter

@PublicationReference(author="Susan T. Dumais",
                      title="Improving the retrieval of information from external sources",
                      year=1991,
                      type=Journal,
                      publication="Behavior Research Methods, Instruments, and Computers",
                      pages={229,236},
                      url="http://www.google.com/url?sa=t&source=web&ct=res&cd=1&url=http%3A%2F%2Fwww.psychonomic.org%2Fsearch%2Fview.cgi%3Fid%3D5145&ei=o7joSdGEHY-itgPLre3tAQ&usg=AFQjCNEvm6PZEL6_Hk3XThI6DQ-gGx9EnQ&sig2=-gjFzNroJQirwGtwjaJvgQ")
public class LogLocalTermWeighter
extends AbstractLocalTermWeighter

Implements the log-based local term weighting scheme. Takes in a vector of term counts and for positive entries, it makes the weight log(1 + count). 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
LogLocalTermWeighter() Creates a new LogLocalTermWeighter.
LogLocalTermWeighter(VectorFactory<? extends Vector> vectorFactory) Creates a new LogLocalTermWeighter.

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

LogLocalTermWeighter

public LogLocalTermWeighter()

Creates a new LogLocalTermWeighter.

LogLocalTermWeighter

public LogLocalTermWeighter(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.