org.terrier.matching.models
Class DFI0

java.lang.Object
  extended by org.terrier.matching.models.WeightingModel
      extended by org.terrier.matching.models.DFI0
All Implemented Interfaces:
java.io.Serializable, java.lang.Cloneable, Model

public class DFI0
extends WeightingModel

Implementation of the basic Divergence from Independence model. For details on this model, please see IRRA at TREC 2009: Index Term Weighting Based on Divergence From Independence Model B.T. Dincer, I. Kocabaš and B. Karoğlan. In Proceedings of TREC 2009.

Since:
3.5
Author:
B Taner Dincer and Craig Macdonald
See Also:
Serialized Form

Field Summary
 
Fields inherited from class org.terrier.matching.models.WeightingModel
averageDocumentLength, c, documentFrequency, i, keyFrequency, numberOfDocuments, numberOfPointers, numberOfTokens, numberOfUniqueTerms, termFrequency
 
Constructor Summary
DFI0()
           
 
Method Summary
 java.lang.String getInfo()
          Returns the name of the model.
 double score(double tf, double docLength)
          This method provides the contract for implementing weighting models.
 double score(double tf, double docLength, double n_t, double F_t, double keyFrequency)
          This method provides the contract for implementing weighting models.
 
Methods inherited from class org.terrier.matching.models.WeightingModel
clone, getOverflowed, getParameter, prepare, score, setAverageDocumentLength, setCollectionStatistics, setDocumentFrequency, setEntryStatistics, setKeyFrequency, setNumberOfDocuments, setNumberOfPointers, setNumberOfTokens, setNumberOfUniqueTerms, setParameter, setRequest, setTermFrequency, stirlingPower
 
Methods inherited from class java.lang.Object
equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

DFI0

public DFI0()
Method Detail

getInfo

public java.lang.String getInfo()
Description copied from class: WeightingModel
Returns the name of the model.

Specified by:
getInfo in interface Model
Specified by:
getInfo in class WeightingModel
Returns:
java.lang.String

score

public double score(double tf,
                    double docLength)
Description copied from class: WeightingModel
This method provides the contract for implementing weighting models.

Specified by:
score in class WeightingModel
Parameters:
tf - The term frequency in the document
docLength - the document's length
Returns:
the score assigned to a document with the given tf and docLength, and other preset parameters

score

public double score(double tf,
                    double docLength,
                    double n_t,
                    double F_t,
                    double keyFrequency)
Description copied from class: WeightingModel
This method provides the contract for implementing weighting models.

Specified by:
score in class WeightingModel
Parameters:
tf - The term frequency in the document
docLength - the document's length
n_t - The document frequency of the term
F_t - the term frequency in the collection
keyFrequency - the term frequency in the query
Returns:
the score returned by the implemented weighting model.


Terrier 3.5. Copyright © 2004-2011 University of Glasgow