org.terrier.matching.models.normalisation
Class NormalisationStatic

java.lang.Object
  org.terrier.matching.models.normalisation.Normalisation
      org.terrier.matching.models.normalisation.NormalisationStatic

All Implemented Interfaces:

java.io.Serializable

public class NormalisationStatic
extends Normalisation

This class implements a Normalisation method that forces all term frequencies to the value of the parameter. If field retrieval is enabled, then the parameter is multiplied by the field weight.

Author:

Craig Macdonald

See Also:

Serialized Form

Field Summary

protected java.lang.String

methodName The name of the normalisation method .

Fields inherited from class org.terrier.matching.models.normalisation.Normalisation

averageDocumentLength, idf, Nt, numberOfDocuments, numberOfTokens, parameter, termFrequency

Constructor Summary

NormalisationStatic()

Method Summary

java.lang.String	getInfo() Get the name of the normalisation method.
double	normalise(double tf, double docLength, double termFrequency) Returns a static term frequency.

Methods inherited from class org.terrier.matching.models.normalisation.Normalisation

getParameter, setAverageDocumentLength, setDocumentFrequency, setNumberOfDocuments, setNumberOfTokens, setParameter

Methods inherited from class java.lang.Object

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

Field Detail

methodName

protected final java.lang.String methodName

The name of the normalisation method .

See Also:

Constant Field Values

Constructor Detail

NormalisationStatic

public NormalisationStatic()

Method Detail

getInfo

public java.lang.String getInfo()

Get the name of the normalisation method.

Specified by:

getInfo in class Normalisation

Returns:

Return the name of the normalisation method.

normalise

public double normalise(double tf,
                        double docLength,
                        double termFrequency)

Returns a static term frequency. i.e. tf = (tf > 0) ? parameter : 0

Specified by:

normalise in class Normalisation

Parameters:

tf - The frequency of the query term in the document.

docLength - The number of tokens in the document.

termFrequency - The frequency of the query term in the collection.

Returns:

The normalised term frequency.