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SimpleKLDocModel Class Reference

Doc representation for simple KL divergence retrieval model. More...

#include <SimpleKLDocModel.hpp>

Inheritance diagram for SimpleKLDocModel:

DocumentRep AbsoluteDiscountDocModel DirichletPriorDocModel JelinekMercerDocModel TwoStageDocModel List of all members.

Public Methods

 SimpleKLDocModel (int docID, UnigramLM &collectLM)
 ~SimpleKLDocModel ()
virtual double termWeight (int termID, DocInfo *info)
 term weighting function, weight(w) = p_seen(w)/p_unseen(w)

virtual double scoreConstant ()
 doc-specific constant term in the scoring formula

virtual double unseenCoeff ()=0
 a(d)

virtual double seenProb (double termFreq, int termID)=0
 p(w|d), w seen


Protected Attributes

UnigramLM & refLM

Detailed Description

Doc representation for simple KL divergence retrieval model.

abstract interface of doc representation for smoothed document unigram model

adapt a smoothed document language model interface to a DocumentRep interface 

 p(w|d) = q(w|d) if w seen
        = a(d) * Pc(w)  if w unseen
   where,  a(d) controls the probability mass allocated to all unseen words and     Pc(w) is the collection language model

Constructor & Destructor Documentation

SimpleKLDocModel::SimpleKLDocModel (  int    docID,
UnigramLM &    collectLM
)  [inline]
 

SimpleKLDocModel::~SimpleKLDocModel (    )  [inline]
 

Member Function Documentation

virtual double SimpleKLDocModel::scoreConstant (    )  [inline, virtual]
 

doc-specific constant term in the scoring formula

Implements DocumentRep.

virtual double SimpleKLDocModel::seenProb (  double    termFreq,
int    termID
)  [pure virtual]
 

p(w|d), w seen

Implemented in JelinekMercerDocModel, DirichletPriorDocModel, AbsoluteDiscountDocModel, and TwoStageDocModel.

virtual double SimpleKLDocModel::termWeight (  int    termID,
DocInfo *    info
)  [inline, virtual]
 

term weighting function, weight(w) = p_seen(w)/p_unseen(w)

Implements DocumentRep.

virtual double SimpleKLDocModel::unseenCoeff (    )  [pure virtual]
 

a(d)

Implemented in JelinekMercerDocModel, DirichletPriorDocModel, AbsoluteDiscountDocModel, and TwoStageDocModel.

Member Data Documentation

UnigramLM& SimpleKLDocModel::refLM [protected]
 

The documentation for this class was generated from the following file:
Generated on Mon Sep 30 14:14:19 2002 for LEMUR by doxygen1.2.18