uk.ac.gla.terrier.matching.models.aftereffect
Class B

java.lang.Object
  uk.ac.gla.terrier.matching.models.aftereffect.AfterEffect
      uk.ac.gla.terrier.matching.models.aftereffect.B

All Implemented Interfaces:

java.io.Serializable

public class B
extends AfterEffect

This class implements the B model for the first normalisation by after effect. B stands for the binomial model.

Version:

$Revision: 1.7 $

Author:

Ben He

See Also:

Serialized Form

Constructor Summary

B()

Method Summary

double	gain(double tf, double documentFrequency, double termFrequency) This method computes the gain of encountering an extra token of the query term.
java.lang.String	getInfo() This method returns the name of the model.

Methods inherited from class uk.ac.gla.terrier.matching.models.aftereffect.AfterEffect

getParameter, setAverageDocumentLength, setParameter

Methods inherited from class java.lang.Object

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

Constructor Detail

B

public B()

Method Detail

getInfo

public java.lang.String getInfo()

This method returns the name of the model.

Specified by:

getInfo in class AfterEffect

Returns:

String Return the name of the model.

gain

public double gain(double tf,
                   double documentFrequency,
                   double termFrequency)

This method computes the gain of encountering an extra token of the query term.

Specified by:

gain in class AfterEffect

Parameters:

tf - The term frequency in the document

documentFrequency - The document frequency of the term

termFrequency - the term frequency in the collection

Returns:

the gain returned by the implemented formula.