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XLingDocModel Class Reference

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

#include <XLingDocModel.hpp>

Inheritance diagram for XLingDocModel:

DocumentRep List of all members.

Public Methods

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

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

virtual double scoreConstant () const

Protected Attributes

const 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

XLingDocModel::XLingDocModel DOCID_T    docID,
const 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.

XLingDocModel::~XLingDocModel   [inline]
 


Member Function Documentation

virtual double XLingDocModel::scoreConstant   const [inline, virtual]
 

Unused.

Returns:
lambda

Implements DocumentRep.

virtual double XLingDocModel::termWeight TERMID_T    termID,
const 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))).

Implements DocumentRep.


Member Data Documentation

bool 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 XLingDocModel::lambda [protected]
 

smoothing coefficient

double XLingDocModel::numTerms [protected]
 

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

const Index* XLingDocModel::refIndex [protected]
 

Index for the collection.


The documentation for this class was generated from the following file:
Generated on Wed Nov 3 13:00:02 2004 for Lemur Toolkit by doxygen1.2.18