gtsam/gtsam/nonlinear/NonlinearFactorGraph.h

271 lines
9.8 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 NonlinearFactorGraph.h
* @brief Factor Graph consisting of non-linear factors
* @author Frank Dellaert
* @author Carlos Nieto
* @author Christian Potthast
*/
// \callgraph
#pragma once
#include <gtsam/geometry/Point2.h>
#include <gtsam/nonlinear/NonlinearFactor.h>
#include <gtsam/nonlinear/GraphvizFormatting.h>
#include <gtsam/inference/FactorGraph.h>
#include <gtsam/nonlinear/PriorFactor.h>
#include <memory>
#include <functional>
namespace gtsam {
// Forward declarations
class Values;
class Ordering;
class GaussianFactorGraph;
class SymbolicFactorGraph;
template<typename T>
class Expression;
template<typename T>
class ExpressionFactor;
/**
* A NonlinearFactorGraph is a graph of non-Gaussian, i.e. non-linear factors,
* which derive from NonlinearFactor. The values structures are typically (in
* SAM) more general than just vectors, e.g., Rot3 or Pose3, which are objects
* in non-linear manifolds. Linearizing the non-linear factor graph creates a
* linear factor graph on the tangent vector space at the linearization point.
* Because the tangent space is a true vector space, the config type will be
* an VectorValues in that linearized factor graph.
* @addtogroup nonlinear
*/
class GTSAM_EXPORT NonlinearFactorGraph: public FactorGraph<NonlinearFactor> {
public:
typedef FactorGraph<NonlinearFactor> Base;
typedef NonlinearFactorGraph This;
typedef std::shared_ptr<This> shared_ptr;
/// @name Standard Constructors
/// @{
/** Default constructor */
NonlinearFactorGraph() {}
/** Construct from iterator over factors */
template<typename ITERATOR>
NonlinearFactorGraph(ITERATOR firstFactor, ITERATOR lastFactor) : Base(firstFactor, lastFactor) {}
/** Construct from container of factors (shared_ptr or plain objects) */
template<class CONTAINER>
explicit NonlinearFactorGraph(const CONTAINER& factors) : Base(factors) {}
/** Implicit copy/downcast constructor to override explicit template container constructor */
template<class DERIVEDFACTOR>
NonlinearFactorGraph(const FactorGraph<DERIVEDFACTOR>& graph) : Base(graph) {}
/// @}
/// @name Testable
/// @{
/** print */
void print(
const std::string& str = "NonlinearFactorGraph: ",
const KeyFormatter& keyFormatter = DefaultKeyFormatter) const override;
/** print errors along with factors*/
void printErrors(const Values& values, const std::string& str = "NonlinearFactorGraph: ",
const KeyFormatter& keyFormatter = DefaultKeyFormatter,
const std::function<bool(const Factor* /*factor*/, double /*whitenedError*/, size_t /*index*/)>&
printCondition = [](const Factor *,double, size_t) {return true;}) const;
/** Test equality */
bool equals(const NonlinearFactorGraph& other, double tol = 1e-9) const;
/// @}
/// @name Standard Interface
/// @{
/** unnormalized error, \f$ \sum_i 0.5 (h_i(X_i)-z)^2 / \sigma^2 \f$ in the most common case */
double error(const Values& values) const;
/** Unnormalized probability. O(n) */
double probPrime(const Values& values) const;
/**
* Create a symbolic factor graph
*/
std::shared_ptr<SymbolicFactorGraph> symbolic() const;
/**
* Compute a fill-reducing ordering using COLAMD.
*/
Ordering orderingCOLAMD() const;
/**
* Compute a fill-reducing ordering with constraints using CCOLAMD
*
* @param constraints is a map of Key->group, where 0 is unconstrained, and higher
* group numbers are further back in the ordering. Only keys with nonzero group
* indices need to appear in the constraints, unconstrained is assumed for all
* other variables
*/
Ordering orderingCOLAMDConstrained(const FastMap<Key, int>& constraints) const;
/// Linearize a nonlinear factor graph
std::shared_ptr<GaussianFactorGraph> linearize(const Values& linearizationPoint) const;
/// typdef for dampen functions used below
typedef std::function<void(const std::shared_ptr<HessianFactor>& hessianFactor)> Dampen;
/**
* Instead of producing a GaussianFactorGraph, pre-allocate and linearize directly
* into a HessianFactor. Avoids the many mallocs and pointer indirection in constructing
* a new graph, and hence useful in case a dense solve is appropriate for your problem.
* An optional lambda function can be used to apply damping on the filled Hessian.
* No parallelism is exploited, because all the factors write in the same memory.
*/
std::shared_ptr<HessianFactor> linearizeToHessianFactor(
const Values& values, const Dampen& dampen = nullptr) const;
/**
* Instead of producing a GaussianFactorGraph, pre-allocate and linearize directly
* into a HessianFactor. Avoids the many mallocs and pointer indirection in constructing
* a new graph, and hence useful in case a dense solve is appropriate for your problem.
* An ordering is given that still decides how the Hessian is laid out.
* An optional lambda function can be used to apply damping on the filled Hessian.
* No parallelism is exploited, because all the factors write in the same memory.
*/
std::shared_ptr<HessianFactor> linearizeToHessianFactor(
const Values& values, const Ordering& ordering, const Dampen& dampen = nullptr) const;
/// Linearize and solve in one pass.
/// Calls linearizeToHessianFactor, densely solves the normal equations, and updates the values.
Values updateCholesky(const Values& values,
const Dampen& dampen = nullptr) const;
/// Linearize and solve in one pass.
/// Calls linearizeToHessianFactor, densely solves the normal equations, and updates the values.
Values updateCholesky(const Values& values, const Ordering& ordering,
const Dampen& dampen = nullptr) const;
/// Clone() performs a deep-copy of the graph, including all of the factors
NonlinearFactorGraph clone() const;
/**
* Rekey() performs a deep-copy of all of the factors, and changes
* keys according to a mapping.
*
* Keys not specified in the mapping will remain unchanged.
*
* @param rekey_mapping is a map of old->new keys
* @result a cloned graph with updated keys
*/
NonlinearFactorGraph rekey(const std::map<Key,Key>& rekey_mapping) const;
/**
* Directly add ExpressionFactor that implements |h(x)-z|^2_R
* @param h expression that implements measurement function
* @param z measurement
* @param R model
*/
template<typename T>
void addExpressionFactor(const SharedNoiseModel& R, const T& z,
const Expression<T>& h) {
this->emplace_shared<ExpressionFactor<T>>(R, z, h);
}
/**
* Convenience method which adds a PriorFactor to the factor graph.
* @param key Variable key
* @param prior The variable's prior value
* @param model Noise model for prior factor
*/
template<typename T>
void addPrior(Key key, const T& prior,
const SharedNoiseModel& model = nullptr) {
emplace_shared<PriorFactor<T>>(key, prior, model);
}
/**
* Convenience method which adds a PriorFactor to the factor graph.
* @param key Variable key
* @param prior The variable's prior value
* @param covariance Covariance matrix.
*
* Note that the smart noise model associated with the prior factor
* automatically picks the right noise model (e.g. a diagonal noise model
* if the provided covariance matrix is diagonal).
*/
template<typename T>
void addPrior(Key key, const T& prior, const Matrix& covariance) {
emplace_shared<PriorFactor<T>>(key, prior, covariance);
}
/// @}
/// @name Graph Display
/// @{
using FactorGraph::dot;
using FactorGraph::saveGraph;
/// Output to graphviz format, stream version, with Values/extra options.
void dot(std::ostream& os, const Values& values,
const KeyFormatter& keyFormatter = DefaultKeyFormatter,
const GraphvizFormatting& writer = GraphvizFormatting()) const;
/// Output to graphviz format string, with Values/extra options.
std::string dot(
const Values& values,
const KeyFormatter& keyFormatter = DefaultKeyFormatter,
const GraphvizFormatting& writer = GraphvizFormatting()) const;
/// output to file with graphviz format, with Values/extra options.
void saveGraph(
const std::string& filename, const Values& values,
const KeyFormatter& keyFormatter = DefaultKeyFormatter,
const GraphvizFormatting& writer = GraphvizFormatting()) const;
/// @}
private:
/**
* Linearize from Scatter rather than from Ordering. Made private because
* it doesn't include gttic.
*/
std::shared_ptr<HessianFactor> linearizeToHessianFactor(
const Values& values, const Scatter& scatter, const Dampen& dampen = nullptr) const;
#ifdef GTSAM_ENABLE_BOOST_SERIALIZATION
/** Serialization function */
friend class boost::serialization::access;
template<class ARCHIVE>
void serialize(ARCHIVE & ar, const unsigned int /*version*/) {
ar & boost::serialization::make_nvp("NonlinearFactorGraph",
boost::serialization::base_object<Base>(*this));
}
#endif
};
/// traits
template<>
struct traits<NonlinearFactorGraph> : public Testable<NonlinearFactorGraph> {
};
} //\ namespace gtsam