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OkapiRetMethod Class Reference

The Okapi BM25 retrieval function, as described in their TREC-3 paper. More...

#include <OkapiRetMethod.hpp>

Inheritance diagram for OkapiRetMethod:

List of all members.

Public Methods
	OkapiRetMethod (Index &dbIndex,ScoreAccumulator &accumulator)
virtual	~OkapiRetMethod ()
virtual TextQueryRep*	computeTextQueryRep (TextQuery &qry)
	compute the query representation for a text query (caller responsible for deleting the memory of the generated new instance).
virtual DocumentRep*	computeDocRep (int docID)
	compute the doc representation (caller responsible for deleting the memory of the generated new instance).
virtual ScoreFunction*	scoreFunc ()
	return the scoring function pointer.
virtual void	updateTextQuery (TextQueryRep &origRep,DocIDSet &relDocs)
	It's suspected that there is a bug in the implementation of feedback; the performance is not as expected.
void	setTFParam (OkapiParameter::TFParam &tfWeightParam)
void	setFeedbackParam (OkapiParameter::FeedbackParam &feedbackParam)
Static Public Methods
double	RSJWeight (double r,double R,double n,double N)
	Compute the Robertson Spark Jones Weight.
Protected Attributes
OkapiScoreFunc*	scFunc
OkapiParameter::TFParam	tfParam
OkapiParameter::FeedbackParam	fbParam

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Detailed Description

The Okapi BM25 retrieval function, as described in their TREC-3 paper.

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Constructor & Destructor Documentation

OkapiRetMethod::OkapiRetMethod ( Index & dbIndex, ScoreAccumulator & accumulator )

OkapiRetMethod::~OkapiRetMethod ( ) [inline, virtual]

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Member Function Documentation

double OkapiRetMethod::RSJWeight ( double r, double R, double n, double N ) [inline, static]

Compute the Robertson Spark Jones Weight.

DocumentRep * OkapiRetMethod::computeDocRep ( int docID ) [inline, virtual]

compute the doc representation (caller responsible for deleting the memory of the generated new instance). Reimplemented from TextQueryRetMethod.

TextQueryRep * OkapiRetMethod::computeTextQueryRep ( TextQuery & qry ) [inline, virtual]

compute the query representation for a text query (caller responsible for deleting the memory of the generated new instance). Reimplemented from TextQueryRetMethod.

ScoreFunction * OkapiRetMethod::scoreFunc ( ) [inline, virtual]

return the scoring function pointer. Reimplemented from TextQueryRetMethod.

void OkapiRetMethod::setFeedbackParam ( OkapiParameter::FeedbackParam & feedbackParam ) [inline]

void OkapiRetMethod::setTFParam ( OkapiParameter::TFParam & tfWeightParam ) [inline]

void OkapiRetMethod::updateTextQuery ( TextQueryRep & origRep, DocIDSet & relDocs ) [virtual]

It's suspected that there is a bug in the implementation of feedback; the performance is not as expected. Reimplemented from TextQueryRetMethod.

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Member Data Documentation

OkapiParameter::FeedbackParam OkapiRetMethod::fbParam [protected]

OkapiScoreFunc * OkapiRetMethod::scFunc [protected]

OkapiParameter::TFParam OkapiRetMethod::tfParam [protected]

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The documentation for this class was generated from the following files:

• OkapiRetMethod.hpp
• OkapiRetMethod.cpp

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