gtsam/inference/FactorGraph.h

235 lines
7.6 KiB
C++

/**
* @file FactorGraph.h
* @brief Factor Graph Base Class
* @author Carlos Nieto
* @author Christian Potthast
* @author Michael Kaess
*/
// \callgraph
#pragma once
#include <boost/shared_ptr.hpp>
#include <boost/foreach.hpp>
//#include <boost/serialization/map.hpp>
//#include <boost/serialization/list.hpp>
//#include <boost/serialization/vector.hpp>
//#include <boost/serialization/shared_ptr.hpp>
#include <boost/pool/pool_alloc.hpp>
#include <gtsam/base/types.h>
#include <gtsam/base/Testable.h>
#include <gtsam/inference/BayesNet.h>
#include <gtsam/inference/graph.h>
namespace gtsam {
/**
* 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 Testable<FactorGraph<Factor> > {
public:
typedef Factor factor_type;
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;
protected:
/** Collection of factors */
std::vector<sharedFactor> factors_;
// /**
// * Return an ordering in first argument, potentially using a set of
// * keys that need to appear last, and potentially restricting scope
// */
// void getOrdering(Ordering& ordering, const std::set<varid_t>& lastKeys,
// boost::optional<const std::set<varid_t>&> scope = boost::none) const;
public:
/** ------------------ Creating Factor Graphs ---------------------------- */
/** Default constructor */
FactorGraph() {}
/** convert from Bayes net */
template<class Conditional>
FactorGraph(const BayesNet<Conditional>& bayesNet);
// /** convert from Bayes net while permuting at the same time */
// template<class Conditional>
// FactorGraph(const BayesNet<Conditional>& bayesNet, const Inference::Permutation& permutation);
/** convert from a derived type */
template<class Derived>
FactorGraph(const Derived& factorGraph);
/** Add a factor */
template<class DerivedFactor>
void push_back(const boost::shared_ptr<DerivedFactor>& factor);
/** push back many factors */
void push_back(const FactorGraph<Factor>& factors);
/** ------------------ Querying Factor Graphs ---------------------------- */
/** print out graph */
void print(const std::string& s = "FactorGraph") const;
/** Check equality */
bool equals(const FactorGraph& 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 */
inline const_iterator begin() const { return factors_.begin();}
inline const_iterator end() const { return factors_.end(); }
/** Get a specific factor by index */
inline sharedFactor operator[](size_t i) const { assert(i<factors_.size()); return factors_[i]; }
/** Get the first factor */
inline sharedFactor front() const { return factors_.front(); }
/** Get the last factor */
inline sharedFactor back() const { return factors_.back(); }
/** return the number of factors and NULLS */
inline size_t size() const { return factors_.size();}
/** return the number valid factors */
size_t nrFactors() const;
// /** return keys in some random order */
// Ordering keys() const;
// /**
// * Compute colamd ordering, including I/O, constrained ordering,
// * and shared pointer version.
// */
// Ordering getOrdering() const;
// boost::shared_ptr<Ordering> getOrdering_() const;
// Ordering getOrdering(const std::set<varid_t>& scope) const;
// Ordering getConstrainedOrdering(const std::set<varid_t>& lastKeys) const;
// /**
// * find the minimum spanning tree using boost graph library
// */
// template<class Key, class Factor2> PredecessorMap<Key>
// SL-NEEDED? findMinimumSpanningTree() const;
//
// /**
// * Split the graph into two parts: one corresponds to the given spanning tree,
// * and the other corresponds to the rest of the factors
// */
// SL-NEEDED? template<class Key, class Factor2> void split(const PredecessorMap<Key>& tree,
// FactorGraph<Factor>& Ab1, FactorGraph<Factor>& Ab2) const;
// /**
// * find the minimum spanning tree using DSF
// */
// std::pair<FactorGraph<Factor> , FactorGraph<Factor> >
// SL-NEEDED? splitMinimumSpanningTree() const;
// /**
// * Check consistency of the index map, useful for debugging
// */
// void checkGraphConsistency() const;
/** ----------------- Modifying Factor Graphs ---------------------------- */
/** STL begin and end, so we can use BOOST_FOREACH */
inline iterator begin() { return factors_.begin();}
inline 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); }
/** 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);
// /**
// * Find all the factors that involve the given node and remove them
// * from the factor graph
// * @param key the key for the given node
// */
// std::vector<sharedFactor> findAndRemoveFactors(varid_t key);
//
// /** remove singleton variables and the related factors */
// std::pair<FactorGraph<Factor>, std::set<varid_t> > removeSingletons();
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
/**
* 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 Factor>
FactorGraph<Factor> combine(const FactorGraph<Factor>& fg1, const FactorGraph<Factor>& fg2);
// /**
// * Extract and combine all the factors that involve a given node
// * Put this here as not all Factors have a combine constructor
// * @param key the key for the given node
// * @return the combined linear factor
// */
// template<class Factor> boost::shared_ptr<Factor>
// removeAndCombineFactors(FactorGraph<Factor>& factorGraph, const varid_t& key);
/**
* 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 Derived>
FactorGraph<Factor>::FactorGraph(const Derived& factorGraph) {
factors_.reserve(factorGraph.size());
BOOST_FOREACH(const typename Derived::sharedFactor& factor, factorGraph) {
this->push_back(factor);
}
}
/* ************************************************************************* */
template<class Factor>
template<class DerivedFactor>
inline void FactorGraph<Factor>::push_back(const boost::shared_ptr<DerivedFactor>& factor) {
#ifndef NDEBUG
factors_.push_back(boost::dynamic_pointer_cast<Factor>(factor)); // add the actual factor
#else
factors_.push_back(boost::static_pointer_cast<Factor>(factor));
#endif
}
} // namespace gtsam