84 lines
2.3 KiB
C++
84 lines
2.3 KiB
C++
/**
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* @file ISAM-inl.h
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* @brief Incremental update functionality (iSAM) for BayesTree.
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* @author Michael Kaess
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*/
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#include <boost/foreach.hpp>
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#include <boost/assign/std/list.hpp> // for operator +=
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using namespace boost::assign;
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#include "Conditional.h"
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#include "ISAM.h"
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#include "BayesTree-inl.h"
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namespace gtsam {
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using namespace std;
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/** Create an empty Bayes Tree */
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template<class Conditional>
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ISAM<Conditional>::ISAM() : BayesTree<Conditional>() {}
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/** Create a Bayes Tree from a Bayes Net */
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template<class Conditional>
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ISAM<Conditional>::ISAM(const BayesNet<Conditional>& bayesNet) :
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BayesTree<Conditional>(bayesNet) {}
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/* ************************************************************************* */
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template<class Conditional>
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template<class Factor>
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void ISAM<Conditional>::update_internal(const FactorGraph<Factor>& newFactors, Cliques& orphans) {
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// Remove the contaminated part of the Bayes tree
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BayesNet<Conditional> bn;
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removeTop(newFactors.keys(), bn, orphans);
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FactorGraph<Factor> factors(bn);
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// add the factors themselves
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factors.push_back(newFactors);
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// create an ordering for the new and contaminated factors
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Ordering ordering;
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if (true) {
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ordering = factors.getOrdering();
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} else {
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list<Symbol> keys = factors.keys();
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keys.sort(); // todo: correct sorting order?
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ordering = keys;
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}
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// Create Index from ordering
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IndexTable<Symbol> index(ordering);
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// eliminate into a Bayes net
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BayesNet<Conditional> bayesNet = eliminate<Factor, Conditional>(factors,ordering);
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// insert conditionals back in, straight into the topless bayesTree
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typename BayesNet<Conditional>::const_reverse_iterator rit;
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for ( rit=bayesNet.rbegin(); rit != bayesNet.rend(); ++rit )
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this->insert(*rit, index);
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int count = 0;
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// add orphans to the bottom of the new tree
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BOOST_FOREACH(sharedClique orphan, orphans) {
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Symbol parentRepresentative = findParentClique(orphan->separator_, index);
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sharedClique parent = (*this)[parentRepresentative];
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parent->children_ += orphan;
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orphan->parent_ = parent; // set new parent!
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}
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}
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template<class Conditional>
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template<class Factor>
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void ISAM<Conditional>::update(const FactorGraph<Factor>& newFactors) {
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Cliques orphans;
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this->update_internal<Factor>(newFactors, orphans);
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}
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}
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/// namespace gtsam
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