gtsam/inference/ISAM2.h

108 lines
3.6 KiB
C++

/**
* @file ISAM2.h
* @brief Incremental update functionality (ISAM2) for BayesTree, with fluid relinearization.
* @author Michael Kaess
*/
// \callgraph
#pragma once
#include <map>
#include <list>
#include <vector>
#include <boost/serialization/map.hpp>
#include <boost/serialization/list.hpp>
#include <stdexcept>
#include <gtsam/base/Testable.h>
#include <gtsam/inference/FactorGraph.h>
#include <gtsam/nonlinear/NonlinearFactorGraph.h>
#include <gtsam/inference/BayesNet.h>
#include <gtsam/inference/BayesTree.h>
#include <gtsam/inference/Key.h>
#include <gtsam/inference/SymbolMap.h>
namespace gtsam {
typedef SymbolMap<GaussianFactor::shared_ptr> CachedFactors;
template<class Conditional, class Config>
class ISAM2: public BayesTree<Conditional> {
protected:
// current linearization point
Config theta_;
Config thetaFuture_; // lin point of next iteration
// for keeping all original nonlinear factors
NonlinearFactorGraph<Config> nonlinearFactors_;
// cached intermediate results for restarting computation in the middle
CachedFactors cached_;
// the linear solution, an update to the estimate in theta
VectorConfig delta_;
VectorConfig deltaMarked_;
// variables that have been updated, requiring the corresponding factors to be relinearized
std::list<Symbol> marked_;
public:
/** Create an empty Bayes Tree */
ISAM2();
/** Create a Bayes Tree from a Bayes Net */
ISAM2(const NonlinearFactorGraph<Config>& fg, const Ordering& ordering, const Config& config);
/** Destructor */
virtual ~ISAM2() {
}
typedef typename BayesTree<Conditional>::sharedClique sharedClique;
typedef typename BayesTree<Conditional>::Cliques Cliques;
/**
* ISAM2. (update_internal provides access to list of orphans for drawing purposes)
*/
void linear_update(const FactorGraph<GaussianFactor>& newFactors);
void find_all(sharedClique clique, std::list<Symbol>& keys, const std::list<Symbol>& marked); // helper function
void fluid_relinearization(double relinearize_threshold);
void update_internal(const NonlinearFactorGraph<Config>& newFactors,
const Config& newTheta, Cliques& orphans,
double wildfire_threshold, double relinearize_threshold, bool relinearize);
void update(const NonlinearFactorGraph<Config>& newFactors, const Config& newTheta,
double wildfire_threshold = 0., double relinearize_threshold = 0., bool relinearize = true);
// needed to create initial estimates (note that this will be the linearization point in the next step!)
const Config getLinearizationPoint() const {return thetaFuture_;}
// estimate based on incomplete delta (threshold!)
const Config calculateEstimate() const {return expmap(theta_, delta_);}
// estimate based on full delta (note that this is based on the actual current linearization point)
const Config calculateBestEstimate() const {return expmap(theta_, optimize2(*this, 0.));}
const std::list<Symbol>& getMarkedUnsafe() const { return marked_; }
const NonlinearFactorGraph<Config>& getFactorsUnsafe() const { return nonlinearFactors_; }
const Config& getThetaUnsafe() const { return theta_; }
const VectorConfig& getDeltaUnsafe() const { return delta_; }
size_t lastAffectedVariableCount;
size_t lastAffectedFactorCount;
size_t lastAffectedCliqueCount;
private:
std::list<size_t> getAffectedFactors(const std::list<Symbol>& keys) const;
boost::shared_ptr<GaussianFactorGraph> relinearizeAffectedFactors(const std::set<Symbol>& affectedKeys) const;
FactorGraph<GaussianFactor> getCachedBoundaryFactors(Cliques& orphans);
}; // ISAM2
} /// namespace gtsam