gtsam/cpp/BayesNet.h

104 lines
3.0 KiB
C++

/**
* @file BayesNet
* @brief Bayes network
* @author Frank Dellaert
*/
// \callgraph
#pragma once
#include <vector>
#include <boost/shared_ptr.hpp>
#include <boost/serialization/map.hpp>
#include <boost/serialization/vector.hpp>
#include <boost/serialization/shared_ptr.hpp>
#include "Testable.h"
namespace gtsam {
class Ordering;
/**
* Bayes network
* This is the base class for SymbolicBayesNet, DiscreteBayesNet, and GaussianBayesNet
* corresponding to what is used for the "Conditional" template argument:
* a SymbolicConditional, ConditionalProbabilityTable, or a ConditionalGaussian
*/
template<class Conditional>
class BayesNet: public Testable<BayesNet<Conditional> > {
public:
/** We store shared pointers to Conditional densities */
typedef typename boost::shared_ptr<Conditional> conditional_ptr;
typedef typename std::vector<conditional_ptr> Conditionals;
typedef typename Conditionals::const_iterator const_iterator;
typedef typename Conditionals::const_reverse_iterator const_reverse_iterator;
protected:
/**
* Conditional densities are stored in reverse topological sort order (i.e., leaves first,
* parents last), which corresponds to the elimination ordering if so obtained,
* and is consistent with the column (block) ordering of an upper triangular matrix.
*/
Conditionals conditionals_;
/**
* O(log n) random access on keys will provided by a map from keys to vector index.
*/
typedef std::map<std::string, int> Indices;
Indices indices_;
/** O(log n) lookup from key to node index */
inline int index(const std::string& key) const {
Indices::const_iterator it = indices_.find(key); // get node index
assert( it != indices_.end() );
return it->second;
}
public:
/** print */
void print(const std::string& s = "") const;
/** check equality */
bool equals(const BayesNet& other, double tol = 1e-9) const;
/** insert: use reverse topological sort (i.e. parents last / elimination order) */
void insert(const boost::shared_ptr<Conditional>& conditional);
/** size is the number of nodes */
inline size_t size() const {
return conditionals_.size();
}
/** return keys in reverse topological sort order, i.e., elimination order */
Ordering ordering() const;
/** O(log n) random access to Conditional by key */
inline conditional_ptr operator[](const std::string& key) const {
int i = index(key);
return conditionals_[i];
}
/** return iterators. FD: breaks encapsulation? */
const_iterator const begin() const {return conditionals_.begin();}
const_iterator const end() const {return conditionals_.end();}
const_reverse_iterator const rbegin() const {return conditionals_.rbegin();}
const_reverse_iterator const rend() const {return conditionals_.rend();}
private:
/** Serialization function */
friend class boost::serialization::access;
template<class Archive>
void serialize(Archive & ar, const unsigned int version) {
ar & BOOST_SERIALIZATION_NVP(conditionals_);
ar & BOOST_SERIALIZATION_NVP(indices_);
}
};
} /// namespace gtsam