gtsam/gtsam/linear/GaussianISAM.cpp

83 lines
3.0 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 GaussianISAM
* @brief Linear ISAM only
* @author Michael Kaess
*/
#include <gtsam/linear/GaussianISAM.h>
using namespace std;
using namespace gtsam;
// Explicitly instantiate so we don't have to include everywhere
#include <gtsam/inference/ISAM-inl.h>
template class ISAM<GaussianConditional>;
//namespace ublas = boost::numeric::ublas;
namespace gtsam {
/* ************************************************************************* */
GaussianFactor::shared_ptr GaussianISAM::marginalFactor(Index j) const {
return Super::marginalFactor(j, &EliminateQR);
}
/* ************************************************************************* */
BayesNet<GaussianConditional>::shared_ptr GaussianISAM::marginalBayesNet(Index j) const {
return Super::marginalBayesNet(j, &EliminateQR);
}
/* ************************************************************************* */
std::pair<Vector, Matrix> GaussianISAM::marginal(Index j) const {
GaussianConditional::shared_ptr conditional = marginalBayesNet(j)->front();
Matrix R = conditional->get_R();
return make_pair(conditional->get_d(), (R.transpose() * R).inverse());
}
/* ************************************************************************* */
BayesNet<GaussianConditional>::shared_ptr GaussianISAM::jointBayesNet(
Index key1, Index key2) const {
return Super::jointBayesNet(key1, key2, &EliminateQR);
}
/* ************************************************************************* */
void optimize(const GaussianISAM::sharedClique& clique, VectorValues& result) {
// parents are assumed to already be solved and available in result
GaussianISAM::Clique::const_reverse_iterator it;
for (it = clique->rbegin(); it!=clique->rend(); it++) {
GaussianConditional::shared_ptr cg = *it;
Vector x = cg->solve(result); // Solve for that variable
result[cg->key()] = x; // store result in partial solution
}
BOOST_FOREACH(const GaussianISAM::sharedClique& child, clique->children_) {
optimize(child, result);
}
}
/* ************************************************************************* */
VectorValues optimize(const GaussianISAM& bayesTree) {
VectorValues result(bayesTree.dims_);
// starting from the root, call optimize on each conditional
optimize(bayesTree.root(), result);
return result;
}
/* ************************************************************************* */
BayesNet<GaussianConditional> GaussianISAM::shortcut(sharedClique clique, sharedClique root) {
return clique->shortcut(root,&EliminateQR);
}
/* ************************************************************************* */
} /// namespace gtsam