DiscreteMarginals.cpp

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/* ----------------------------------------------------------------------------
 
 * GTSAM Copyright 2010, Georgia Tech Research Corporation,
 * Atlanta, Georgia 30332-0415
 * All Rights Reserved
 * Authors: Frank Dellaert, et al. (see THANKS for the full author list)
 
 * See LICENSE for the license information
 
 * -------------------------------------------------------------------------- */
 
#include <gtsam/discrete/DiscreteMarginals.h>
 
namespace gtsam {
 
/* ************************************************************************* */
DiscreteMarginals::DiscreteMarginals(const DiscreteFactorGraph& graph) {
  bayesTree_ = graph.eliminateMultifrontal();
}
 
/* ************************************************************************* */
DiscreteFactor::shared_ptr DiscreteMarginals::operator()(Key variable) const {
  // Compute marginal
  DiscreteFactor::shared_ptr marginalFactor =
      bayesTree_->marginalFactor(variable, &EliminateDiscrete);
  return marginalFactor;
}
 
/* ************************************************************************* */
Vector DiscreteMarginals::marginalProbabilities(const DiscreteKey& key) const {
  // Compute marginal
  DiscreteFactor::shared_ptr marginalFactor = this->operator()(key.first);
 
  // Create result
  Vector vResult(key.second);
  for (size_t state = 0; state < key.second; ++state) {
    DiscreteValues values;
    values[key.first] = state;
    vResult(state) = (*marginalFactor)(values);
  }
  return vResult;
}
 
/* ************************************************************************* */
void DiscreteMarginals::print(const std::string& s,
                              const KeyFormatter formatter) const {
  std::cout << (s.empty() ? "Discrete Marginals of:" : s + " ") << std::endl;
  bayesTree_->print("", formatter);
}
 
} /* namespace gtsam */