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 More...
virtual	~GibbsOperator ()
	Destructor. More...
Size	nbrDrawnVar () const
	Getters and setters. More...
void	setNbrDrawnVar (Size nbr)
bool	isDrawnAtRandom () const
void	setDrawnAtRandom (bool atRandom)
Instantiation	monteCarloSample ()
	draws a Monte Carlo sample More...
Instantiation	nextSample (Instantiation prev)
	draws next sample of Gibbs sampling More...

Protected Attributes
Size	_counting
	number of samples drawn More...
const IBayesNet< GUM_SCALAR > &	_sampling_bn
const NodeProperty< Idx > *	_hardEv
Sequence< NodeId >	_samplingNodes
Size	_nbr
bool	_atRandom

Detailed Description

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

class containing all variables and methods required for Gibbssampling

Definition at line 50 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 37 of file gibbsOperator_tpl.h.

References gum::GibbsOperator< GUM_SCALAR >::__updateSamplingNodes().

                                                            :
      _counting(0),
      _sampling_bn(BN), _hardEv(hardEv), _nbr(nbr), _atRandom(atRandom) {
    __updateSamplingNodes();
    GUM_CONSTRUCTOR(GibbsOperator);
  }

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~GibbsOperator()

template<typename GUM_SCALAR >

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

virtual

Destructor.

Definition at line 48 of file gibbsOperator_tpl.h.

                                              {
    GUM_DESTRUCTOR(GibbsOperator);
  }

Member Function Documentation

__drawVarMonteCarlo()

template<typename GUM_SCALAR >

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

private

Definition at line 85 of file gibbsOperator_tpl.h.

References gum::GibbsOperator< GUM_SCALAR >::_sampling_bn, gum::Instantiation::chgVal(), and gum::Instantiation::erase().

Referenced by gum::GibbsOperator< GUM_SCALAR >::monteCarloSample().

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

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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 107 of file gibbsOperator_tpl.h.

References gum::GibbsOperator< GUM_SCALAR >::_sampling_bn, gum::Instantiation::chgVal(), gum::Potential< GUM_SCALAR >::draw(), gum::Instantiation::erase(), gum::MultiDimDecorator< GUM_SCALAR >::nbrDim(), gum::Potential< GUM_SCALAR >::normalize(), and gum::Potential< GUM_SCALAR >::sum().

Referenced by gum::GibbsOperator< GUM_SCALAR >::nextSample().

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

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__updateSamplingNodes()

template<typename GUM_SCALAR >

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

private

Definition at line 53 of file gibbsOperator_tpl.h.

References gum::GibbsOperator< GUM_SCALAR >::_hardEv, gum::GibbsOperator< GUM_SCALAR >::_nbr, gum::GibbsOperator< GUM_SCALAR >::_sampling_bn, gum::GibbsOperator< GUM_SCALAR >::_samplingNodes, gum::SequenceImplementation< Key, Alloc, Gen >::clear(), GUM_ERROR, gum::SequenceImplementation< Key, Alloc, Gen >::insert(), and gum::SequenceImplementation< Key, Alloc, Gen >::size().

Referenced by gum::GibbsOperator< GUM_SCALAR >::GibbsOperator().

                                                          {
    _samplingNodes.clear();
    for (const auto node : _sampling_bn.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();
  }

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isDrawnAtRandom()

template<typename GUM_SCALAR >

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

inline

Definition at line 70 of file gibbsOperator.h.

References gum::GibbsOperator< GUM_SCALAR >::_atRandom.

{ return _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 70 of file gibbsOperator_tpl.h.

References gum::GibbsOperator< GUM_SCALAR >::__drawVarMonteCarlo(), gum::GibbsOperator< GUM_SCALAR >::_hardEv, gum::GibbsOperator< GUM_SCALAR >::_sampling_bn, gum::Instantiation::add(), and gum::Instantiation::chgVal().

Referenced by gum::GibbsBNdistance< GUM_SCALAR >::_computeKL(), gum::GibbsSampling< GUM_SCALAR >::_monteCarloSample(), and gum::GibbsOperator< GUM_SCALAR >::setDrawnAtRandom().

                                                              {
    gum::Instantiation I;

    for (const auto nod : _sampling_bn.topologicalOrder()) {
      I.add(_sampling_bn.variable(nod));
      if (_hardEv != nullptr && _hardEv->exists(nod)) {
        I.chgVal(_sampling_bn.variable(nod), (*_hardEv)[nod]);
      } else {
        __drawVarMonteCarlo(nod, &I);
      }
    }
    return I;
  }

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nbrDrawnVar()

template<typename GUM_SCALAR >

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

inline

Getters and setters.

Definition at line 66 of file gibbsOperator.h.

References gum::GibbsOperator< GUM_SCALAR >::_nbr.

{ return _nbr; }

nextSample()

template<typename GUM_SCALAR >

Instantiation gum::GibbsOperator< GUM_SCALAR >::nextSample

(

Instantiation

prev

)

draws next sample of Gibbs sampling

Definition at line 95 of file gibbsOperator_tpl.h.

References gum::GibbsOperator< GUM_SCALAR >::__GibbsSample(), gum::GibbsOperator< GUM_SCALAR >::_atRandom, gum::GibbsOperator< GUM_SCALAR >::_counting, gum::GibbsOperator< GUM_SCALAR >::_nbr, gum::GibbsOperator< GUM_SCALAR >::_samplingNodes, gum::randomValue(), and gum::SequenceImplementation< Key, Alloc, Gen >::size().

Referenced by gum::GibbsBNdistance< GUM_SCALAR >::_computeKL(), gum::GibbsSampling< GUM_SCALAR >::_draw(), and gum::GibbsOperator< GUM_SCALAR >::setDrawnAtRandom().

                                                                          {
    for (Idx i = 0; i < _nbr; i++) {
      auto pos = _atRandom ? randomValue(_samplingNodes.size())
                           : (_counting % _samplingNodes.size());
      this->__GibbsSample(_samplingNodes[pos], &prev);
      _counting++;
    }
    return prev;
  }

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setDrawnAtRandom()

template<typename GUM_SCALAR >

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

inline

Definition at line 72 of file gibbsOperator.h.

References gum::GibbsOperator< GUM_SCALAR >::_atRandom, gum::GibbsOperator< GUM_SCALAR >::monteCarloSample(), and gum::GibbsOperator< GUM_SCALAR >::nextSample().

{ _atRandom = atRandom; }

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setNbrDrawnVar()

template<typename GUM_SCALAR >

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

inline

Definition at line 68 of file gibbsOperator.h.

References gum::GibbsOperator< GUM_SCALAR >::_nbr.

{ _nbr = nbr; }

Member Data Documentation

_atRandom

template<typename GUM_SCALAR >

bool gum::GibbsOperator< GUM_SCALAR >::_atRandom

protected

Definition at line 90 of file gibbsOperator.h.

Referenced by gum::GibbsOperator< GUM_SCALAR >::isDrawnAtRandom(), gum::GibbsOperator< GUM_SCALAR >::nextSample(), and gum::GibbsOperator< GUM_SCALAR >::setDrawnAtRandom().

_counting

template<typename GUM_SCALAR >

Size gum::GibbsOperator< GUM_SCALAR >::_counting

protected

number of samples drawn

Definition at line 82 of file gibbsOperator.h.

Referenced by gum::GibbsOperator< GUM_SCALAR >::nextSample().

_hardEv

template<typename GUM_SCALAR >

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

protected

Definition at line 84 of file gibbsOperator.h.

Referenced by gum::GibbsOperator< GUM_SCALAR >::__updateSamplingNodes(), and gum::GibbsOperator< GUM_SCALAR >::monteCarloSample().

_nbr

template<typename GUM_SCALAR >

Size gum::GibbsOperator< GUM_SCALAR >::_nbr

protected

Definition at line 87 of file gibbsOperator.h.

Referenced by gum::GibbsOperator< GUM_SCALAR >::__updateSamplingNodes(), gum::GibbsOperator< GUM_SCALAR >::nbrDrawnVar(), gum::GibbsOperator< GUM_SCALAR >::nextSample(), and gum::GibbsOperator< GUM_SCALAR >::setNbrDrawnVar().

_sampling_bn

template<typename GUM_SCALAR >

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

protected

Definition at line 83 of file gibbsOperator.h.

Referenced by gum::GibbsOperator< GUM_SCALAR >::__drawVarMonteCarlo(), gum::GibbsOperator< GUM_SCALAR >::__GibbsSample(), gum::GibbsOperator< GUM_SCALAR >::__updateSamplingNodes(), and gum::GibbsOperator< GUM_SCALAR >::monteCarloSample().

_samplingNodes

template<typename GUM_SCALAR >

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

protected

Definition at line 85 of file gibbsOperator.h.

Referenced by gum::GibbsOperator< GUM_SCALAR >::__updateSamplingNodes(), and gum::GibbsOperator< GUM_SCALAR >::nextSample().

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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