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CosSimRetMethod Class Reference

Cosine similarity retrieval method. More...

#include <CosSimRetMethod.hpp>

Inheritance diagram for CosSimRetMethod:

List of all members.

Public Methods
	CosSimRetMethod (const Index &dbIndex, ScoreAccumulator &accumulator)
	Precomputes the idf values for the collection.
	CosSimRetMethod (const Index &dbIndex, const string &L2file, ScoreAccumulator &accumulator)
virtual	~CosSimRetMethod ()
virtual TextQueryRep *	computeTextQueryRep (const TermQuery &qry)
	compute the query representation for a text query (caller responsible for deleting the memory of the generated new instance)
virtual TextQueryRep *	computeTextQueryRep (DOCID_T docid)
	compute a query rep for an existing doc
virtual DocumentRep *	computeDocRep (DOCID_T 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 &qryRep, const DocIDSet &relDocs)
	Use same as TFIDFRetMethod.
void	setFeedbackParam (CosSimParameter::FeedbackParam &feedbackParam)
Protected Methods
double	docNorm (DOCID_T docID)
	compute the L2 norm for a given docID.
void	loadDocNorms ()
	load the precomputed L2 norms support file.
Protected Attributes
double *	idfV
ScoreFunction *	scFunc
double *	docNorms
int	numDocs
int	numTerms
Parameters
CosSimParameter::FeedbackParam	fbParam
const string &	L2FileName
	Name of support file containing the precomputed L2 norms.

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Detailed Description

Cosine similarity retrieval method.

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Constructor & Destructor Documentation

CosSimRetMethod::CosSimRetMethod (  const Index &    dbIndex, ScoreAccumulator &    accumulator )

Precomputes the idf values for the collection.

CosSimRetMethod::CosSimRetMethod (  const Index &    dbIndex, const string &    L2file, ScoreAccumulator &    accumulator )

Precomputes the idf values for the collection. Loads the precomputed L2 document norms from L2File (if present). This support file is optional, if it is not found, L2 norms will be computed during scoring and cached across queries.

CosSimRetMethod::~CosSimRetMethod (    )  [virtual]

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Member Function Documentation

virtual DocumentRep* CosSimRetMethod::computeDocRep (  DOCID_T    docID )  [inline, virtual]

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

virtual TextQueryRep* CosSimRetMethod::computeTextQueryRep (  DOCID_T    docid )  [inline, virtual]

compute a query rep for an existing doc Reimplemented from TextQueryRetMethod.

virtual TextQueryRep* CosSimRetMethod::computeTextQueryRep (  const TermQuery &    qry )  [inline, virtual]

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

double CosSimRetMethod::docNorm (  DOCID_T    docID )  [protected]

compute the L2 norm for a given docID.

void CosSimRetMethod::loadDocNorms (    )  [protected]

load the precomputed L2 norms support file.

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

return the scoring function pointer Implements TextQueryRetMethod.

void CosSimRetMethod::setFeedbackParam (  CosSimParameter::FeedbackParam &    feedbackParam )  [inline]

void CosSimRetMethod::updateTextQuery (  TextQueryRep &    qryRep, const DocIDSet &    relDocs )  [virtual]

Use same as TFIDFRetMethod. Implements TextQueryRetMethod.

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Member Data Documentation

double* CosSimRetMethod::docNorms [protected]

CosSimParameter::FeedbackParam CosSimRetMethod::fbParam [protected]

double* CosSimRetMethod::idfV [protected]

const string& CosSimRetMethod::L2FileName [protected]

Name of support file containing the precomputed L2 norms.

int CosSimRetMethod::numDocs [protected]

int CosSimRetMethod::numTerms [protected]

ScoreFunction* CosSimRetMethod::scFunc [protected]

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

• CosSimRetMethod.hpp
• CosSimRetMethod.cpp

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