org.terrier.matching.models.normalisation
Class Normalisation2exp

java.lang.Object
  extended by org.terrier.matching.models.normalisation.Normalisation
      extended by org.terrier.matching.models.normalisation.Normalisation2exp
All Implemented Interfaces:
java.io.Serializable

public class Normalisation2exp
extends Normalisation

This class implements the DFR normalisation 2 with natural logorithm.

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
Normalisation2exp()
          The default constructor.
 
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

Normalisation2exp

public Normalisation2exp()
The default constructor. The hyper-parameter value is set to 1.0 by default.

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.


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