Terrier IR Platform
2.2.1

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

java.lang.Object
  extended by uk.ac.gla.terrier.matching.models.aftereffect.AfterEffect
      extended by uk.ac.gla.terrier.matching.models.aftereffect.LL
All Implemented Interfaces:
java.io.Serializable

public class LL
extends AfterEffect

This class implements the LL model for the first normalisation by after effect. LL stands for the log of laplace succession.

Version:
$Revision: 1.7 $
Author:
Ben He
See Also:
Serialized Form

Constructor Summary
LL()
          The default constructor.
 
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()
          Returns the name of the method.
 
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

LL

public LL()
The default constructor.

Method Detail

getInfo

public java.lang.String getInfo()
Returns the name of the method.

Specified by:
getInfo in class AfterEffect
Returns:
The name of the method.

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.

Terrier IR Platform
2.2.1

Terrier Information Retrieval Platform 2.2.1. Copyright 2004-2008 University of Glasgow