org.terrier.matching.models
Class BM25F

java.lang.Object
  extended by org.terrier.matching.models.WeightingModel
      extended by org.terrier.matching.models.PerFieldNormWeightingModel
          extended by org.terrier.matching.models.BM25F
All Implemented Interfaces:
java.io.Serializable, java.lang.Cloneable, Model

public class BM25F
extends PerFieldNormWeightingModel

A convenience subclass of PerFieldNormWeightingModel setup to do specifically BM25F, as described by [Zaragoza TREC-2004]. [Robertson CIKM-2004] describe a different model, which does not normalise frequencies in a per-field manner.

References:

Since:
3.0
Author:
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
BM25F()
          Constructs an instance of the BM25F
 
Method Summary
 java.lang.String getInfo()
          Returns the name of the model.
 
Methods inherited from class org.terrier.matching.models.PerFieldNormWeightingModel
prepare, score, score, score, setCollectionStatistics, setEntryStatistics
 
Methods inherited from class org.terrier.matching.models.WeightingModel
clone, getOverflowed, getParameter, setAverageDocumentLength, setDocumentFrequency, 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

BM25F

public BM25F()
      throws java.lang.Exception
Constructs an instance of the BM25F

Throws:
java.lang.Exception
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
Overrides:
getInfo in class PerFieldNormWeightingModel
Returns:
java.lang.String


Terrier 3.5. Copyright © 2004-2011 University of Glasgow