gtsam/cpp/BayesTree.h

102 lines
2.6 KiB
C++

/**
* @file BayesTree
* @brief Bayes Tree is a tree of cliques of a Bayes Chain
* @author Frank Dellaert
*/
// \callgraph
#pragma once
#include <map>
#include <list>
#include <vector>
#include <boost/serialization/map.hpp>
#include <boost/serialization/list.hpp>
#include "Testable.h"
#include "BayesNet.h"
namespace gtsam {
/**
* Bayes tree
* Templated on the Conditional class, the type of node in the underlying Bayes chain.
* This could be a ConditionalProbabilityTable, a ConditionalGaussian, or a SymbolicConditional
*/
template<class Conditional>
class BayesTree: public Testable<BayesTree<Conditional> > {
public:
typedef boost::shared_ptr<Conditional> conditional_ptr;
private:
/** A Node in the tree is an incomplete Bayes net: the variables
* in the Bayes net are the frontal nodes, and the variables conditioned
* on is the separator. We also have pointers up and down the tree.
*/
struct Node : public BayesNet<Conditional> {
typedef boost::shared_ptr<Node> shared_ptr;
shared_ptr parent_;
std::list<std::string> separator_; /** separator keys */
std::list<shared_ptr> children_;
//* Constructor */
Node(const boost::shared_ptr<Conditional>& conditional);
/** The size *includes* the separator */
size_t size() const { return this->conditionals_.size() + separator_.size(); }
/** print this node */
void print(const std::string& s="Bayes tree node") const;
/** print this node and entire subtree below it*/
void printTree(const std::string& indent) const;
};
/** Map from keys to Node */
typedef boost::shared_ptr<Node> node_ptr;
typedef std::map<std::string, node_ptr> Nodes;
Nodes nodes_;
/** Roor clique */
node_ptr root_;
/** add a clique */
node_ptr addClique(const conditional_ptr& conditional, node_ptr parent_clique=node_ptr());
public:
/** Create an empty Bayes Tree */
BayesTree();
/** Create a Bayes Tree from a Bayes Net */
BayesTree(const BayesNet<Conditional>& bayesNet);
/** Destructor */
virtual ~BayesTree() {}
/** print */
void print(const std::string& s = "") const;
/** check equality */
bool equals(const BayesTree<Conditional>& other, double tol = 1e-9) const;
/** insert a new conditional */
void insert(const boost::shared_ptr<Conditional>& conditional);
/** number of cliques */
inline size_t size() const { return nodes_.size();}
/** return root clique */
boost::shared_ptr<BayesNet<Conditional> > root() const {return root_;}
/** return marginal on any variable */
boost::shared_ptr<Conditional> marginal(const std::string& key) const;
}; // BayesTree
} /// namespace gtsam