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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 (Index &dbIndex, ScoreAccumulator &accumulator)
	Precomputes the idf values for the collection.
	CosSimRetMethod (Index &dbIndex, const char *L2file, ScoreAccumulator &accumulator)
virtual	~CosSimRetMethod ()
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 TextQueryRep *	computeTextQueryRep (int docid)
	compute a query rep for an existing doc (DOCID_T needed).
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 &qryRep, DocIDSet &relDocs)
	Use same as TFIDFRetMethod.
void	setFeedbackParam (CosSimParameter::FeedbackParam &feedbackParam)
Protected Methods
double	docNorm (int 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 char *	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 (  Index &    dbIndex, ScoreAccumulator &    accumulator )

Precomputes the idf values for the collection.

CosSimRetMethod::CosSimRetMethod (  Index &    dbIndex, const char *    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 (  int    docID )  [inline, virtual]

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

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

compute a query rep for an existing doc (DOCID_T needed). Reimplemented from TextQueryRetMethod.

virtual TextQueryRep* CosSimRetMethod::computeTextQueryRep (  TextQuery &    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 (  int    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, 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 char* 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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