gtsam/gtsam/linear/GaussianSequentialSolver.cpp

122 lines
4.2 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 GaussianSequentialSolver.cpp
* @author Richard Roberts
* @date Oct 19, 2010
*/
#include <gtsam/3rdparty/Eigen/Eigen/Dense>
#include <gtsam/base/timing.h>
#include <gtsam/linear/GaussianSequentialSolver.h>
namespace gtsam {
/* ************************************************************************* */
GaussianSequentialSolver::GaussianSequentialSolver(
const FactorGraph<GaussianFactor>& factorGraph, bool useQR) :
Base(factorGraph), useQR_(useQR) {
}
/* ************************************************************************* */
GaussianSequentialSolver::GaussianSequentialSolver(
const FactorGraph<GaussianFactor>::shared_ptr& factorGraph,
const VariableIndex::shared_ptr& variableIndex, bool useQR) :
Base(factorGraph, variableIndex), useQR_(useQR) {
}
/* ************************************************************************* */
GaussianSequentialSolver::shared_ptr GaussianSequentialSolver::Create(
const FactorGraph<GaussianFactor>::shared_ptr& factorGraph,
const VariableIndex::shared_ptr& variableIndex, bool useQR) {
return shared_ptr(
new GaussianSequentialSolver(factorGraph, variableIndex, useQR));
}
/* ************************************************************************* */
void GaussianSequentialSolver::replaceFactors(
const FactorGraph<GaussianFactor>::shared_ptr& factorGraph) {
Base::replaceFactors(factorGraph);
}
/* ************************************************************************* */
GaussianBayesNet::shared_ptr GaussianSequentialSolver::eliminate() const {
if (useQR_)
return Base::eliminate(&EliminateQR);
else
return Base::eliminate(&EliminatePreferCholesky);
}
/* ************************************************************************* */
VectorValues::shared_ptr GaussianSequentialSolver::optimize() const {
static const bool debug = false;
if(debug) this->factors_->print("GaussianSequentialSolver, eliminating ");
if(debug) this->eliminationTree_->print("GaussianSequentialSolver, elimination tree ");
tic(1,"eliminate");
// Eliminate using the elimination tree
GaussianBayesNet::shared_ptr bayesNet(this->eliminate());
toc(1,"eliminate");
if(debug) bayesNet->print("GaussianSequentialSolver, Bayes net ");
// Allocate the solution vector if it is not already allocated
// VectorValues::shared_ptr solution = allocateVectorValues(*bayesNet);
tic(2,"optimize");
// Back-substitute
VectorValues::shared_ptr solution(
new VectorValues(gtsam::optimize(*bayesNet)));
toc(2,"optimize");
if(debug) solution->print("GaussianSequentialSolver, solution ");
return solution;
}
/* ************************************************************************* */
GaussianFactor::shared_ptr GaussianSequentialSolver::marginalFactor(Index j) const {
if (useQR_)
return Base::marginalFactor(j,&EliminateQR);
else
return Base::marginalFactor(j,&EliminatePreferCholesky);
}
/* ************************************************************************* */
Matrix GaussianSequentialSolver::marginalCovariance(Index j) const {
FactorGraph<GaussianFactor> fg;
GaussianConditional::shared_ptr conditional;
if (useQR_) {
fg.push_back(Base::marginalFactor(j, &EliminateQR));
conditional = EliminateQR(fg, 1).first;
} else {
fg.push_back(Base::marginalFactor(j, &EliminatePreferCholesky));
conditional = EliminatePreferCholesky(fg, 1).first;
}
return conditional->computeInformation().inverse();
}
/* ************************************************************************* */
GaussianFactorGraph::shared_ptr
GaussianSequentialSolver::jointFactorGraph(const std::vector<Index>& js) const {
if (useQR_)
return GaussianFactorGraph::shared_ptr(new GaussianFactorGraph(
*Base::jointFactorGraph(js, &EliminateQR)));
else
return GaussianFactorGraph::shared_ptr(new GaussianFactorGraph(
*Base::jointFactorGraph(js, &EliminatePreferCholesky)));
}
} /// namespace gtsam