org.terrier.matching.models.normalisation
Class NormalisationJ

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

All Implemented Interfaces:

java.io.Serializable

public class NormalisationJ
extends Normalisation

This class implements the tf normalisation based on Jelinek-Mercer smoothing for language modelling.

Author:

Ben He

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

NormalisationJ()

Method Summary

java.lang.String	getInfo() Get the name of the normalisation method.
double	normalise(double tf, double docLength, double termFrequency) This method gets the normalised 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

NormalisationJ

public NormalisationJ()

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)

This method gets the normalised term frequency.

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.