BP Class Reference

Class for belief propagation algorithm. More...

#include <bp.h>

Inheritance diagram for BP:

List of all members.

Public Member Functions
	BP (FactorGraph *factorGraph, BPParams *bpParams, Array< Array< Predicate * > * > *queryFormulas=NULL)
	Constructor.
	~BP ()
	Destructor.
void	init ()
	Initializes belief propagation.
void	infer ()
	Performs Belief Propagation inference.
void	printNetwork (ostream &out)
	Prints out the network.
void	printProbabilities (ostream &out)
	Prints the probabilities of each predicate to a stream.
void	getChangedPreds (vector< string > &changedPreds, vector< float > &probs, vector< float > &oldProbs, const float &probDelta)
	Puts the predicates whose probability has changed with respect to the reference vector oldProbs by more than probDelta in string form and the corresponding probabilities of each predicate in two vectors.
double	getProbability (GroundPredicate *const &gndPred)
	Gets the probability of a ground predicate.
double	getProbabilityH (GroundPredicate *const &gndPred)
	Gets the probability of a ground predicate.
void	printTruePreds (ostream &out)
	Prints each predicate with a probability of 0.5 or greater to a stream.
void	printTruePredsH (ostream &out)
	Prints each predicate with a probability of 0.5 or greater to a stream.

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Detailed Description

Class for belief propagation algorithm.

This version of BP works on a factor graph, which can be in a lifted representation or not.

Definition at line 84 of file bp.h.

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Constructor & Destructor Documentation

BP::BP	(	FactorGraph *	factorGraph,
		BPParams *	bpParams,
		Array< Array< Predicate * > * > *	queryFormulas = NULL
	)			[inline]

Constructor.

Requires a factor graph and a set of parameters for the algorithm. Optionally, a set of query formulas is used.

Definition at line 92 of file bp.h.

References BPParams::convergenceThresh, BPParams::convergeRequiredItrCnt, BPParams::maxSeconds, BPParams::maxSteps, and BPParams::outputNetwork.

    : Inference(NULL, -1, false, queryFormulas)
  {
    factorGraph_ = factorGraph;
    maxSteps_ = bpParams->maxSteps;
    maxSeconds_ = bpParams->maxSeconds;
    convergenceThresh_ = bpParams->convergenceThresh;
    convergeRequiredItrCnt_ = bpParams->convergeRequiredItrCnt;
    outputNetwork_ = bpParams->outputNetwork;
  }

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Member Function Documentation

void BP::init

(

)

[inline, virtual]

Initializes belief propagation.

The factor graph is built.

Implements Inference.

Definition at line 114 of file bp.h.

References FactorGraph::init(), Timer::printTime(), Timer::reset(), and Timer::time().

  {
    Timer timer1;
    cout << "Initializing ";
    cout << "Belief Propagation..." << endl;

    factorGraph_->init();
    if (bpdebug)
    {
      cout << "[init] ";
      Timer::printTime(cout, timer1.time());
      cout << endl;
      timer1.reset();
    }
  }

void BP::getChangedPreds	(	vector< string > &	changedPreds,
		vector< float > &	probs,
		vector< float > &	oldProbs,
		const float &	probDelta
	)			[inline, virtual]

Puts the predicates whose probability has changed with respect to the reference vector oldProbs by more than probDelta in string form and the corresponding probabilities of each predicate in two vectors.

Currently not implemented.

Parameters:

	changedPreds	Predicates whose probability have changed more than probDelta are put here.
	probs	The probabilities corresponding to the predicates in changedPreds are put here.
	oldProbs	Reference probabilities for checking for changes.
	probDelta	If probability of an atom has changed more than this value, then it is considered to have changed.

Implements Inference.

Definition at line 364 of file bp.h.

  {
  }

double BP::getProbability

(

GroundPredicate *const &

gndPred

)

[inline, virtual]

Gets the probability of a ground predicate.

Parameters:

gndPred

GroundPredicate whose probability is being retrieved.

Returns:

Probability of gndPred if present in state, otherwise 0.

Implements Inference.

Definition at line 375 of file bp.h.

References Node::getConstants(), SuperPred::getConstantTuple(), FactorGraph::getDomain(), GroundPredicate::getId(), FactorGraph::getNode(), FactorGraph::getNumNodes(), SuperPred::getNumTuples(), Domain::getPredicate(), Node::getPredId(), Node::getProbs(), Node::getSuperPred(), and Predicate::same().

  {
    double probs[2];
    Array<int>* constants;
    Predicate* pred;
    unsigned int predId;
    Node* node;
    Domain* domain = factorGraph_->getDomain();
    bool found = false;
    for (int i = 0; i < factorGraph_->getNumNodes(); i++)
    { 
      node = factorGraph_->getNode(i);
      predId = node->getPredId();
      if (predId != gndPred->getId()) continue;
      node->getProbs(probs);         
      SuperPred * superPred = node->getSuperPred();

      if (superPred)
      {        
        for (int index = 0; index < superPred->getNumTuples(); index++)
        {
          constants = superPred->getConstantTuple(index);
          pred = domain->getPredicate(constants, predId);
          if (!pred->same(gndPred))
          {
            delete pred;
            continue;
          }
          delete pred;
          found = true;
          return probs[1];
        }
      }
      else
      {
        constants = node->getConstants(); 
        assert(constants != NULL);
        pred = domain->getPredicate(constants, predId);
        if (!pred->same(gndPred))
        {
          delete pred;
          continue;
        }
        delete pred;
        found = true;
        return probs[1];
      }
    }
    return 0.5;
  }

double BP::getProbabilityH

(

GroundPredicate *const &

gndPred

)

[inline, virtual]

Gets the probability of a ground predicate.

Currently not implemented.

Parameters:

gndPred

GroundPredicate whose probability is being retrieved.

Returns:

Probability of gndPred if present in state, otherwise 0.

Implements Inference.

Definition at line 432 of file bp.h.

  {
    return 0.0;
  }

void BP::printTruePreds

(

ostream &

out

)

[inline, virtual]

Prints each predicate with a probability of 0.5 or greater to a stream.

Currently not implemented.

Implements Inference.

Definition at line 441 of file bp.h.

  {
  }

void BP::printTruePredsH

(

ostream &

out

)

[inline, virtual]

Prints each predicate with a probability of 0.5 or greater to a stream.

Currently not implemented.

Implements Inference.

Definition at line 449 of file bp.h.

  {
  }

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

• src/infer/bp.h

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