gtsam/gtsam/hybrid/HybridJunctionTree.h

72 lines
2.6 KiB
C++

/* ----------------------------------------------------------------------------
* 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
* -------------------------------------------------------------------------- */
/**
* @file HybridJunctionTree.h
* @date Mar 11, 2022
* @author Fan Jiang
*/
#pragma once
#include <gtsam/hybrid/HybridBayesTree.h>
#include <gtsam/hybrid/HybridFactorGraph.h>
#include <gtsam/inference/JunctionTree.h>
namespace gtsam {
// Forward declarations
class HybridEliminationTree;
/**
* An EliminatableClusterTree, i.e., a set of variable clusters with factors,
* arranged in a tree, with the additional property that it represents the
* clique tree associated with a Bayes net.
*
* In GTSAM a junction tree is an intermediate data structure in multifrontal
* variable elimination. Each node is a cluster of factors, along with a
* clique of variables that are eliminated all at once. In detail, every node k
* represents a clique (maximal fully connected subset) of an associated chordal
* graph, such as a chordal Bayes net resulting from elimination.
*
* The difference with the BayesTree is that a JunctionTree stores factors,
* whereas a BayesTree stores conditionals, that are the product of eliminating
* the factors in the corresponding JunctionTree cliques.
*
* The tree structure and elimination method are exactly analogous to the
* EliminationTree, except that in the JunctionTree, at each node multiple
* variables are eliminated at a time.
*
* \addtogroup Multifrontal
* \nosubgrouping
*/
class GTSAM_EXPORT HybridJunctionTree
: public JunctionTree<HybridBayesTree, HybridFactorGraph> {
public:
typedef JunctionTree<HybridBayesTree, HybridFactorGraph>
Base; ///< Base class
typedef HybridJunctionTree This; ///< This class
typedef boost::shared_ptr<This> shared_ptr; ///< Shared pointer to this class
/**
* Build the elimination tree of a factor graph using precomputed column
* structure.
* @param factorGraph The factor graph for which to build the elimination tree
* @param structure The set of factors involving each variable. If this is
* not precomputed, you can call the Create(const FactorGraph<DERIVEDFACTOR>&)
* named constructor instead.
* @return The elimination tree
*/
HybridJunctionTree(const HybridEliminationTree& eliminationTree);
};
} // namespace gtsam