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