lemur::retrieval::SimpleKLDocModel Class Reference

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

#include <SimpleKLDocModel.hpp>

Inheritance diagram for lemur::retrieval::SimpleKLDocModel:

List of all members.

Public Member Functions
	SimpleKLDocModel (lemur::api::DOCID_T docID, const lemur::langmod::UnigramLM &collectLM, int dl=1, const double *prMass=NULL, SimpleKLParameter::SmoothStrategy strat=SimpleKLParameter::INTERPOLATE)
	~SimpleKLDocModel ()
virtual double	termWeight (lemur::api::TERMID_T termID, const lemur::api::DocInfo *info) const
	term weighting function, weight(w) = p_seen(w)/p_unseen(w)
virtual double	scoreConstant () const
	doc-specific constant term in the scoring formula
virtual double	unseenCoeff () const =0
	a(d)
virtual double	seenProb (double termFreq, lemur::api::TERMID_T termID) const =0
	p(w|d), w seen
Protected Attributes
const lemur::langmod::UnigramLM &	refLM
const double *	docPrMass
SimpleKLParameter::SmoothStrategy	strategy

---

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

lemur::retrieval::SimpleKLDocModel::SimpleKLDocModel (  lemur::api::DOCID_T  docID, const lemur::langmod::UnigramLM &  collectLM, int  dl = 1, const double *  prMass = NULL, SimpleKLParameter::SmoothStrategy  strat = SimpleKLParameter::INTERPOLATE )  [inline]

lemur::retrieval::SimpleKLDocModel::~SimpleKLDocModel (   )  [inline]

---

Member Function Documentation

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

doc-specific constant term in the scoring formula Implements lemur::api::DocumentRep.

virtual double lemur::retrieval::SimpleKLDocModel::seenProb (  double  termFreq, lemur::api::TERMID_T  termID )  const [pure virtual]

p(w|d), w seen Implemented in lemur::retrieval::JelinekMercerDocModel, lemur::retrieval::DirichletPriorDocModel, lemur::retrieval::AbsoluteDiscountDocModel, and lemur::retrieval::TwoStageDocModel.

virtual double lemur::retrieval::SimpleKLDocModel::termWeight (  lemur::api::TERMID_T  termID, const lemur::api::DocInfo *  info )  const [inline, virtual]

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

virtual double lemur::retrieval::SimpleKLDocModel::unseenCoeff (   )  const [pure virtual]

a(d) Implemented in lemur::retrieval::JelinekMercerDocModel, lemur::retrieval::DirichletPriorDocModel, lemur::retrieval::AbsoluteDiscountDocModel, and lemur::retrieval::TwoStageDocModel.

---

Member Data Documentation

const double* lemur::retrieval::SimpleKLDocModel::docPrMass [protected]

const lemur::langmod::UnigramLM& lemur::retrieval::SimpleKLDocModel::refLM [protected]

SimpleKLParameter::SmoothStrategy lemur::retrieval::SimpleKLDocModel::strategy [protected]

---

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

• SimpleKLDocModel.hpp

---