gum::GibbsOperator< GUM_SCALAR > Class Template Reference

class containing all variables and methods required for Gibbssampling More...

#include <agrum/BN/inference/gibbsOperator.h>

Inheritance diagram for gum::GibbsOperator< GUM_SCALAR >:

Collaboration diagram for gum::GibbsOperator< GUM_SCALAR >:

Public Member Functions
	GibbsOperator (const IBayesNet< GUM_SCALAR > &BN, const NodeProperty< Idx > *hardEv, Size nbr=1, bool atRandom=false)
	constructor
virtual	~GibbsOperator ()
	Destructor.
Size	nbrDrawnVar () const
	Getters and setters.
void	setNbrDrawnVar (Size nbr)
bool	isDrawnAtRandom () const
void	setDrawnAtRandom (bool atRandom)
Instantiation	monteCarloSample ()
	draws a Monte Carlo sample
Instantiation	nextSample (Instantiation prev)
	draws next sample of Gibbs sampling

Protected Member Functions
void	updateSamplingNodes_ ()

Protected Attributes
Size	counting_
const IBayesNet< GUM_SCALAR > &	samplingBn_
const NodeProperty< Idx > *	hardEv_
Sequence< NodeId >	samplingNodes_
Size	nbr_
bool	atRandom_

Private Member Functions
void	_drawVarMonteCarlo_ (NodeId nod, Instantiation *I)
void	_GibbsSample_ (NodeId id, Instantiation *I)
	change in Instantiation I a new drawn value for id

Detailed Description

template<typename GUM_SCALAR>
class gum::GibbsOperator< GUM_SCALAR >

class containing all variables and methods required for Gibbssampling

Definition at line 67 of file gibbsOperator.h.

Constructor & Destructor Documentation

GibbsOperator()

template<typename GUM_SCALAR>

gum::GibbsOperator< GUM_SCALAR >::GibbsOperator	(	const IBayesNet< GUM_SCALAR > &	BN,
		const NodeProperty< Idx > *	hardEv,
		Size	nbr = 1,
		bool	atRandom = false )

constructor

Definition at line 58 of file gibbsOperator_tpl.h.

                                                                                      :
      counting_(0), samplingBn_(BN), hardEv_(hardEv), nbr_(nbr), atRandom_(atRandom) {
    GUM_CONSTRUCTOR(GibbsOperator);
  }

References GibbsOperator(), atRandom_, counting_, hardEv_, nbr_, and samplingBn_.

Referenced by gum::GibbsBNdistance< GUM_SCALAR >::GibbsBNdistance(), gum::GibbsBNdistance< GUM_SCALAR >::GibbsBNdistance(), GibbsOperator(), gum::GibbsSampling< GUM_SCALAR >::GibbsSampling(), and ~GibbsOperator().

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~GibbsOperator()

template<typename GUM_SCALAR>

gum::GibbsOperator< GUM_SCALAR >::~GibbsOperator ( )

virtual

Destructor.

Definition at line 67 of file gibbsOperator_tpl.h.

                                              {
    GUM_DESTRUCTOR(GibbsOperator);
  }

References GibbsOperator().

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Member Function Documentation

_drawVarMonteCarlo_()

template<typename GUM_SCALAR>

void gum::GibbsOperator< GUM_SCALAR >::_drawVarMonteCarlo_ ( NodeId nod, Instantiation * I )

private

Definition at line 102 of file gibbsOperator_tpl.h.

                                                                                    {
    gum::Instantiation Itop(*I);
    Itop.erase(samplingBn_.variable(nod));
    I->chgVal(samplingBn_.variable(nod), samplingBn_.cpt(nod).extract(Itop).draw());
  }

References gum::Instantiation::chgVal(), gum::Instantiation::erase(), and samplingBn_.

Referenced by monteCarloSample().

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_GibbsSample_()

template<typename GUM_SCALAR>

void gum::GibbsOperator< GUM_SCALAR >::_GibbsSample_ ( NodeId id, Instantiation * I )

private

change in Instantiation I a new drawn value for id

Definition at line 122 of file gibbsOperator_tpl.h.

                                                                             {
    gum::Instantiation Itop(*I);
    Itop.erase(samplingBn_.variable(id));
    gum::Tensor< GUM_SCALAR > p = samplingBn_.cpt(id).extract(Itop);
    for (const auto nod: samplingBn_.children(id))
      p *= samplingBn_.cpt(nod).extract(Itop);
    GUM_ASSERT(p.nbrDim() == 1);
    if (p.sum() != 0) {
      p.normalize();
      I->chgVal(samplingBn_.variable(id), p.draw());
    }
  }

References gum::Instantiation::chgVal(), gum::Tensor< GUM_SCALAR >::draw(), gum::Instantiation::erase(), gum::MultiDimDecorator< GUM_SCALAR >::nbrDim(), gum::Tensor< GUM_SCALAR >::normalize(), samplingBn_, and gum::Tensor< GUM_SCALAR >::sum().

Referenced by nextSample().

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isDrawnAtRandom()

template<typename GUM_SCALAR>

bool gum::GibbsOperator< GUM_SCALAR >::isDrawnAtRandom ( ) const

inline

Definition at line 87 of file gibbsOperator.h.

{ return atRandom_; }

References atRandom_.

monteCarloSample()

template<typename GUM_SCALAR>

Instantiation gum::GibbsOperator< GUM_SCALAR >::monteCarloSample

(

)

draws a Monte Carlo sample

returns a MC sample This is not a really sample since we take into account evidence without care about parent of evidence, etc. This is just a not-so-bad first sample for GibbsSampler

Definition at line 87 of file gibbsOperator_tpl.h.

                                                              {
    gum::Instantiation I;
 
    for (const auto nod: samplingBn_.topologicalOrder()) {
      I.add(samplingBn_.variable(nod));
      if (hardEv_ != nullptr && hardEv_->exists(nod)) {
        I.chgVal(samplingBn_.variable(nod), (*hardEv_)[nod]);
      } else {
        _drawVarMonteCarlo_(nod, &I);
      }
    }
    return I;
  }

References _drawVarMonteCarlo_(), gum::Instantiation::add(), gum::Instantiation::chgVal(), hardEv_, and samplingBn_.

Referenced by gum::GibbsBNdistance< GUM_SCALAR >::computeKL_(), and gum::GibbsSampling< GUM_SCALAR >::monteCarloSample_().

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nbrDrawnVar()

template<typename GUM_SCALAR>

Size gum::GibbsOperator< GUM_SCALAR >::nbrDrawnVar ( ) const

inline

Getters and setters.

Definition at line 83 of file gibbsOperator.h.

{ return nbr_; }

References nbr_.

nextSample()

template<typename GUM_SCALAR>

Instantiation gum::GibbsOperator< GUM_SCALAR >::nextSample

(

Instantiation

prev

)

draws next sample of Gibbs sampling

Definition at line 109 of file gibbsOperator_tpl.h.

                                                                          {
    for (Idx i = 0; i < nbr_; i++) {
      auto pos
          = atRandom_ ? randomValue(samplingNodes_.size()) : (counting_ % samplingNodes_.size());
      this->_GibbsSample_(samplingNodes_[pos], &prev);
      counting_++;
    }
    return prev;
  }

References _GibbsSample_(), atRandom_, counting_, nbr_, gum::randomValue(), and samplingNodes_.

Referenced by gum::GibbsBNdistance< GUM_SCALAR >::computeKL_(), and gum::GibbsSampling< GUM_SCALAR >::draw_().

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setDrawnAtRandom()

template<typename GUM_SCALAR>

void gum::GibbsOperator< GUM_SCALAR >::setDrawnAtRandom ( bool atRandom )

inline

Definition at line 89 of file gibbsOperator.h.

{ atRandom_ = atRandom; }

References atRandom_.

setNbrDrawnVar()

template<typename GUM_SCALAR>

void gum::GibbsOperator< GUM_SCALAR >::setNbrDrawnVar ( Size nbr )

inline

Definition at line 85 of file gibbsOperator.h.

{ nbr_ = nbr; }

References nbr_.

updateSamplingNodes_()

template<typename GUM_SCALAR>

void gum::GibbsOperator< GUM_SCALAR >::updateSamplingNodes_ ( )

protected

Definition at line 72 of file gibbsOperator_tpl.h.

                                                         {
    samplingNodes_.clear();
    for (const auto node: samplingBn_.nodes())
      if (hardEv_ == nullptr || !hardEv_->exists(node)) { samplingNodes_.insert(node); }
    if (samplingNodes_.size() == 0) {
      GUM_ERROR(InvalidArgument, "No node to sample (too many nodes or too much evidence)!")
    }
    if (nbr_ > samplingNodes_.size()) nbr_ = samplingNodes_.size();
  }

References GUM_ERROR, hardEv_, nbr_, samplingBn_, and samplingNodes_.

Referenced by gum::GibbsSampling< GUM_SCALAR >::burnIn_(), and gum::GibbsBNdistance< GUM_SCALAR >::computeKL_().

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Member Data Documentation

atRandom_

template<typename GUM_SCALAR>

bool gum::GibbsOperator< GUM_SCALAR >::atRandom_

protected

Definition at line 104 of file gibbsOperator.h.

Referenced by GibbsOperator(), isDrawnAtRandom(), nextSample(), and setDrawnAtRandom().

counting_

template<typename GUM_SCALAR>

Size gum::GibbsOperator< GUM_SCALAR >::counting_

protected

Definition at line 98 of file gibbsOperator.h.

Referenced by GibbsOperator(), and nextSample().

hardEv_

template<typename GUM_SCALAR>

const NodeProperty< Idx >* gum::GibbsOperator< GUM_SCALAR >::hardEv_

protected

Definition at line 100 of file gibbsOperator.h.

Referenced by GibbsOperator(), monteCarloSample(), and updateSamplingNodes_().

nbr_

template<typename GUM_SCALAR>

Size gum::GibbsOperator< GUM_SCALAR >::nbr_

protected

Definition at line 103 of file gibbsOperator.h.

Referenced by GibbsOperator(), nbrDrawnVar(), nextSample(), setNbrDrawnVar(), and updateSamplingNodes_().

samplingBn_

template<typename GUM_SCALAR>

const IBayesNet< GUM_SCALAR >& gum::GibbsOperator< GUM_SCALAR >::samplingBn_

protected

Definition at line 99 of file gibbsOperator.h.

Referenced by GibbsOperator(), _drawVarMonteCarlo_(), _GibbsSample_(), monteCarloSample(), and updateSamplingNodes_().

samplingNodes_

template<typename GUM_SCALAR>

Sequence< NodeId > gum::GibbsOperator< GUM_SCALAR >::samplingNodes_

protected

Definition at line 101 of file gibbsOperator.h.

Referenced by nextSample(), and updateSamplingNodes_().

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

• agrum/BN/inference/tools/gibbsOperator.h
• agrum/BN/inference/tools/gibbsOperator_tpl.h