gtsam/gtsam/inference/FactorGraph.h

242 lines
8.0 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 FactorGraph.h
* @brief Factor Graph Base Class
* @author Carlos Nieto
* @author Christian Potthast
* @author Michael Kaess
*/
// \callgraph
#pragma once
#include <boost/foreach.hpp>
#include <boost/serialization/nvp.hpp>
#include <boost/function.hpp>
#include <gtsam/base/Testable.h>
#include <gtsam/base/FastMap.h>
#include <gtsam/inference/BayesNet.h>
#include <gtsam/inference/graph.h>
namespace gtsam {
// Forward declarations
template<class CONDITIONAL> class BayesTree;
/**
* A factor graph is a bipartite graph with factor nodes connected to variable nodes.
* In this class, however, only factor nodes are kept around.
*
* Templated on the type of factors and values structure.
*/
template<class FACTOR>
class FactorGraph {
public:
typedef FACTOR FactorType;
typedef boost::shared_ptr<FactorGraph<FACTOR> > shared_ptr;
typedef typename boost::shared_ptr<FACTOR> sharedFactor;
typedef typename std::vector<sharedFactor>::iterator iterator;
typedef typename std::vector<sharedFactor>::const_iterator const_iterator;
/** typedef for elimination result */
typedef std::pair<
boost::shared_ptr<typename FACTOR::ConditionalType>,
typename FACTOR::shared_ptr> EliminationResult;
/** typedef for an eliminate subroutine */
typedef boost::function<EliminationResult(const FactorGraph<FACTOR>&, size_t)> Eliminate;
protected:
/** concept check */
GTSAM_CONCEPT_TESTABLE_TYPE(FACTOR)
/** Collection of factors */
std::vector<sharedFactor> factors_;
public:
/** ------------------ Creating Factor Graphs ---------------------------- */
/** Default constructor */
FactorGraph() {}
/** convert from Bayes net */
template<class CONDITIONAL>
FactorGraph(const BayesNet<CONDITIONAL>& bayesNet);
/** convert from Bayes net */
template<class CONDITIONAL>
FactorGraph(const BayesTree<CONDITIONAL>& bayesTree);
/** convert from a derived type */
template<class DERIVEDFACTOR>
FactorGraph(const FactorGraph<DERIVEDFACTOR>& factors) { factors_.insert(end(), factors.begin(), factors.end()); }
/** Add a factor */
template<class DERIVEDFACTOR>
void push_back(const boost::shared_ptr<DERIVEDFACTOR>& factor) { factors_.push_back(sharedFactor(factor)); }
/** push back many factors */
void push_back(const FactorGraph<FACTOR>& factors) { factors_.insert(end(), factors.begin(), factors.end()); }
/** push back many factors with an iterator */
template<typename ITERATOR>
void push_back(ITERATOR firstFactor, ITERATOR lastFactor) { factors_.insert(end(), firstFactor, lastFactor); }
/** push back many factors stored in a vector*/
template<typename DERIVEDFACTOR>
void push_back(const std::vector<boost::shared_ptr<DERIVEDFACTOR> >& factors);
/** ------------------ Querying Factor Graphs ---------------------------- */
/** print out graph */
void print(const std::string& s = "FactorGraph") const;
/** Check equality */
bool equals(const FactorGraph<FACTOR>& fg, double tol = 1e-9) const;
/** const cast to the underlying vector of factors */
operator const std::vector<sharedFactor>&() const { return factors_; }
/** STL begin and end, so we can use BOOST_FOREACH */
const_iterator begin() const { return factors_.begin();}
const_iterator end() const { return factors_.end(); }
/** Get a specific factor by index */
const sharedFactor operator[](size_t i) const { assert(i<factors_.size()); return factors_[i]; }
sharedFactor& operator[](size_t i) { assert(i<factors_.size()); return factors_[i]; }
/** Get the first factor */
sharedFactor front() const { return factors_.front(); }
/** Get the last factor */
sharedFactor back() const { return factors_.back(); }
/** return the number of factors and NULLS */
size_t size() const { return factors_.size();}
/** return the number valid factors */
size_t nrFactors() const;
/** dynamic_cast the factor pointers down or up the class hierarchy */
template<class RELATED>
typename RELATED::shared_ptr dynamicCastFactors() const {
typename RELATED::shared_ptr ret(new RELATED);
ret->reserve(this->size());
BOOST_FOREACH(const sharedFactor& factor, *this) {
typename RELATED::FactorType::shared_ptr castedFactor(boost::dynamic_pointer_cast<typename RELATED::FactorType>(factor));
if(castedFactor)
ret->push_back(castedFactor);
else
throw std::invalid_argument("In FactorGraph<FACTOR>::dynamic_factor_cast(), dynamic_cast failed, meaning an invalid cast was requested.");
}
return ret;
}
/**
* dynamic_cast factor pointers if possible, otherwise convert with a
* constructor of the target type.
*/
template<class TARGET>
typename TARGET::shared_ptr convertCastFactors() const {
typename TARGET::shared_ptr ret(new TARGET);
ret->reserve(this->size());
BOOST_FOREACH(const sharedFactor& factor, *this) {
typename TARGET::FactorType::shared_ptr castedFactor(boost::dynamic_pointer_cast<typename TARGET::FactorType>(factor));
if(castedFactor)
ret->push_back(castedFactor);
else
ret->push_back(typename TARGET::FactorType::shared_ptr(new typename TARGET::FactorType(*factor)));
}
return ret;
}
/** ----------------- Modifying Factor Graphs ---------------------------- */
/** STL begin and end, so we can use BOOST_FOREACH */
iterator begin() { return factors_.begin();}
iterator end() { return factors_.end(); }
/**
* Reserve space for the specified number of factors if you know in
* advance how many there will be (works like std::vector::reserve).
*/
void reserve(size_t size) { factors_.reserve(size); }
/**
* resize the factor graph
*/
void resize(size_t size) { factors_.resize(size); }
/** delete factor without re-arranging indexes by inserting a NULL pointer */
inline void remove(size_t i) { factors_[i].reset();}
/** replace a factor by index */
void replace(size_t index, sharedFactor factor);
private:
/** Serialization function */
friend class boost::serialization::access;
template<class ARCHIVE>
void serialize(ARCHIVE & ar, const unsigned int version) {
ar & BOOST_SERIALIZATION_NVP(factors_);
}
}; // FactorGraph
/** Create a combined joint factor (new style for EliminationTree). */
template<class DERIVED, class KEY>
typename DERIVED::shared_ptr Combine(const FactorGraph<DERIVED>& factors,
const FastMap<KEY, std::vector<KEY> >& variableSlots);
/**
* static function that combines two factor graphs
* @param const &fg1 Linear factor graph
* @param const &fg2 Linear factor graph
* @return a new combined factor graph
*/
template<class FACTORGRAPH>
FACTORGRAPH combine(const FACTORGRAPH& fg1, const FACTORGRAPH& fg2);
/*
* These functions are defined here because they are templated on an
* additional parameter. Putting them in the -inl.h file would mean these
* would have to be explicitly instantiated for any possible derived factor
* type.
*/
/* ************************************************************************* */
template<class FACTOR>
template<class CONDITIONAL>
FactorGraph<FACTOR>::FactorGraph(const BayesNet<CONDITIONAL>& bayesNet) {
factors_.reserve(bayesNet.size());
BOOST_FOREACH(const typename CONDITIONAL::shared_ptr& cond, bayesNet) {
this->push_back(cond->toFactor());
}
}
/* ************************************************************************* */
template<class FACTOR>
template<class DERIVEDFACTOR>
void FactorGraph<FACTOR>::push_back(const std::vector<boost::shared_ptr<DERIVEDFACTOR> >& factors) {
BOOST_FOREACH(const boost::shared_ptr<DERIVEDFACTOR>& factor, factors)
this->push_back(factor);
}
} // namespace gtsam