gtsam/gtsam/symbolic/SymbolicFactor.h

162 lines
5.0 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 SymbolicFactor.h
* @author Richard Roberts
* @date Oct 17, 2010
*/
#pragma once
#include <utility>
#include <boost/shared_ptr.hpp>
#include <boost/assign/list_of.hpp>
#include <boost/make_shared.hpp>
#include <gtsam/inference/Factor.h>
#include <gtsam/inference/Key.h>
namespace gtsam {
// Forward declarations
class SymbolicConditional;
class Ordering;
/** SymbolicFactor represents a symbolic factor that specifies graph topology but is not
* associated with any numerical function.
* \nosubgrouping */
class GTSAM_EXPORT SymbolicFactor : public Factor {
public:
typedef SymbolicFactor This;
typedef Factor Base;
typedef SymbolicConditional ConditionalType;
/** Overriding the shared_ptr typedef */
typedef boost::shared_ptr<This> shared_ptr;
/// @name Standard Interface
/// @{
/** Default constructor for I/O */
SymbolicFactor() {}
/** Construct unary factor */
explicit SymbolicFactor(Key j) :
Base(boost::assign::cref_list_of<1>(j)) {}
/** Construct binary factor */
SymbolicFactor(Key j1, Key j2) :
Base(boost::assign::cref_list_of<2>(j1)(j2)) {}
/** Construct ternary factor */
SymbolicFactor(Key j1, Key j2, Key j3) :
Base(boost::assign::cref_list_of<3>(j1)(j2)(j3)) {}
/** Construct 4-way factor */
SymbolicFactor(Key j1, Key j2, Key j3, Key j4) :
Base(boost::assign::cref_list_of<4>(j1)(j2)(j3)(j4)) {}
/** Construct 5-way factor */
SymbolicFactor(Key j1, Key j2, Key j3, Key j4, Key j5) :
Base(boost::assign::cref_list_of<5>(j1)(j2)(j3)(j4)(j5)) {}
/** Construct 6-way factor */
SymbolicFactor(Key j1, Key j2, Key j3, Key j4, Key j5, Key j6) :
Base(boost::assign::cref_list_of<6>(j1)(j2)(j3)(j4)(j5)(j6)) {}
/** Create symbolic version of any factor */
explicit SymbolicFactor(const Factor& factor) : Base(factor.keys()) {}
virtual ~SymbolicFactor() {}
/// Copy this object as its actual derived type.
SymbolicFactor::shared_ptr clone() const { return boost::make_shared<This>(*this); }
/// @}
/// @name Testable
/// @{
bool equals(const This& other, double tol = 1e-9) const;
/// @}
/// @name Advanced Constructors
/// @{
public:
/** Constructor from a collection of keys */
template<typename KEYITERATOR>
static SymbolicFactor FromIterators(KEYITERATOR beginKey, KEYITERATOR endKey) {
return SymbolicFactor(Base::FromIterators(beginKey, endKey));
}
/** Constructor from a collection of keys */
template<typename KEYITERATOR>
static SymbolicFactor::shared_ptr FromIteratorsShared(KEYITERATOR beginKey, KEYITERATOR endKey) {
SymbolicFactor::shared_ptr result = boost::make_shared<SymbolicFactor>();
result->keys_.assign(beginKey, endKey);
return result;
}
/** Constructor from a collection of keys - compatible with boost::assign::list_of and
* boost::assign::cref_list_of */
template<class CONTAINER>
static SymbolicFactor FromKeys(const CONTAINER& keys) {
return SymbolicFactor(Base::FromKeys(keys));
}
/** Constructor from a collection of keys - compatible with boost::assign::list_of and
* boost::assign::cref_list_of */
template<class CONTAINER>
static SymbolicFactor::shared_ptr FromKeysShared(const CONTAINER& keys) {
return FromIteratorsShared(keys.begin(), keys.end());
}
/// @}
/// @name Standard Interface
/// @{
/** Whether the factor is empty (involves zero variables). */
bool empty() const { return keys_.empty(); }
/** Eliminate the variables in \c keys, in the order specified in \c keys, returning a
* conditional and marginal. */
std::pair<boost::shared_ptr<SymbolicConditional>, boost::shared_ptr<SymbolicFactor> >
eliminate(const Ordering& keys) const;
/// @}
private:
/** Serialization function */
friend class boost::serialization::access;
template<class ARCHIVE>
void serialize(ARCHIVE & ar, const unsigned int version) {
ar & BOOST_SERIALIZATION_BASE_OBJECT_NVP(Base);
}
}; // IndexFactor
// Forward declarations
class SymbolicFactorGraph;
class Ordering;
/** Dense elimination function for symbolic factors. This is usually provided as an argument to
* one of the factor graph elimination functions (see EliminateableFactorGraph). The factor
* graph elimination functions do sparse variable elimination, and use this function to eliminate
* single variables or variable cliques. */
GTSAM_EXPORT std::pair<boost::shared_ptr<SymbolicConditional>, boost::shared_ptr<SymbolicFactor> >
EliminateSymbolic(const SymbolicFactorGraph& factors, const Ordering& keys);
}