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lemur::retrieval::XLingDocModel Class Reference

Doc representation for cross lingual retrieval model. More...

#include <XLingDocModel.hpp>

Inheritance diagram for lemur::retrieval::XLingDocModel:

lemur::api::DocumentRep List of all members.

Public Member Functions

 XLingDocModel (lemur::api::DOCID_T docID, const lemur::api::Index *ind, double l, double nt, bool sM=false)
 Constructor taking optional parameters for smoothing.

 ~XLingDocModel ()
virtual double termWeight (lemur::api::TERMID_T termID, const lemur::api::DocInfo *info) const
 Computes term weight for a given term.

virtual double scoreConstant () const

Protected Attributes

const lemur::api::IndexrefIndex
 Index for the collection.

double numTerms
 denominator (number of terms) for background model probability estimate.

double lambda
 smoothing coefficient

bool docBasedSmooth
 Use term frequency (tf/|V|) when false, use term doc frequency (docCount(t)/Sum_w_in_V(docCount(w))) when true for the background model.


Detailed Description

Doc representation for cross lingual retrieval model.


Constructor & Destructor Documentation

lemur::retrieval::XLingDocModel::XLingDocModel lemur::api::DOCID_T  docID,
const lemur::api::Index ind,
double  l,
double  nt,
bool  sM = false
[inline]
 

Constructor taking optional parameters for smoothing.

Parameters:
docID internal document id for this document.
ind pointer to Index for the document.
l lambda value to use for smoothing term weights.
nt |V| (sM false) or docCount(t)/Sum_w_in_V(docCount(w)) (sM true)
sM whether to use term frequency (tf/|V|) or term doc frequency (docCount(t)/Sum_w_in_V(docCount(w))) for the background model. Default is term frequency.

lemur::retrieval::XLingDocModel::~XLingDocModel  )  [inline]
 


Member Function Documentation

virtual double lemur::retrieval::XLingDocModel::scoreConstant  )  const [inline, virtual]
 

Unused.

Returns:
lambda

Implements lemur::api::DocumentRep.

virtual double lemur::retrieval::XLingDocModel::termWeight lemur::api::TERMID_T  termID,
const lemur::api::DocInfo info
const [inline, virtual]
 

Computes term weight for a given term.

Parameters:
termID the term
info the DocInfo for this document
Returns:
the smoothed term weight for the term using lambda*(dtf/|D|) + (1-lambda)*P(t|C) where P(t|C) is either term frequency (tf/|V|) or term doc frequency (docCount(t)/Sum_w_in_V(docCount(w))).


Member Data Documentation

bool lemur::retrieval::XLingDocModel::docBasedSmooth [protected]
 

Use term frequency (tf/|V|) when false, use term doc frequency (docCount(t)/Sum_w_in_V(docCount(w))) when true for the background model.

double lemur::retrieval::XLingDocModel::lambda [protected]
 

smoothing coefficient

double lemur::retrieval::XLingDocModel::numTerms [protected]
 

denominator (number of terms) for background model probability estimate.

const lemur::api::Index* lemur::retrieval::XLingDocModel::refIndex [protected]
 

Index for the collection.


The documentation for this class was generated from the following file:
Generated on Tue Jun 15 11:03:07 2010 for Lemur by doxygen 1.3.4