lemur::retrieval::OkapiRetMethod Class Reference

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

#include <OkapiRetMethod.hpp>

Inheritance diagram for lemur::retrieval::OkapiRetMethod:

List of all members.

Public Member Functions
	OkapiRetMethod (const lemur::api::Index &dbIndex, lemur::api::ScoreAccumulator &accumulator)
virtual	~OkapiRetMethod ()
virtual lemur::api::TextQueryRep *	computeTextQueryRep (const lemur::api::TermQuery &qry)
virtual lemur::api::DocumentRep *	computeDocRep (lemur::api::DOCID_T docID)
	compute the doc representation (caller responsible for deleting the memory of the generated new instance)
virtual lemur::api::ScoreFunction *	scoreFunc ()
	return the scoring function pointer
virtual void	updateTextQuery (lemur::api::TextQueryRep &origRep, const lemur::api::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 Member Functions
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

lemur::retrieval::OkapiRetMethod::OkapiRetMethod (  const lemur::api::Index &  dbIndex, lemur::api::ScoreAccumulator &  accumulator )

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

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Member Function Documentation

virtual lemur::api::DocumentRep* lemur::retrieval::OkapiRetMethod::computeDocRep (  lemur::api::DOCID_T  docID  )  [inline, virtual]

compute the doc representation (caller responsible for deleting the memory of the generated new instance) Implements lemur::api::TextQueryRetMethod.

virtual lemur::api::TextQueryRep* lemur::retrieval::OkapiRetMethod::computeTextQueryRep (  const lemur::api::TermQuery &  qry  )  [inline, virtual]

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

Compute the Robertson Spark Jones Weight.

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

return the scoring function pointer Implements lemur::api::TextQueryRetMethod.

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

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

void lemur::retrieval::OkapiRetMethod::updateTextQuery (  lemur::api::TextQueryRep &  origRep, const lemur::api::DocIDSet &  relDocs )  [virtual]

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

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Member Data Documentation

OkapiParameter::FeedbackParam lemur::retrieval::OkapiRetMethod::fbParam [protected]

OkapiScoreFunc* lemur::retrieval::OkapiRetMethod::scFunc [protected]

OkapiParameter::TFParam lemur::retrieval::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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