73 lines
2.0 KiB
C++
73 lines
2.0 KiB
C++
/*
|
|
* EliminationTree.h
|
|
* Created on: Feb 4, 2010
|
|
* @Author: Kai Ni
|
|
* @Author: Frank Dellaert
|
|
* @brief: The elimination tree
|
|
*/
|
|
|
|
#pragma once
|
|
|
|
#include <set>
|
|
#include "IndexTable.h"
|
|
#include "ClusterTree.h"
|
|
|
|
namespace gtsam {
|
|
|
|
/**
|
|
* An elimination tree (see Gilbert01bit) associated with a factorg raph and an ordering
|
|
* is a cluster-tree where there is one node j for each variable, and the parent of each node
|
|
* corresponds to the first variable in the ordering that variable j is connected to.
|
|
*/
|
|
template<class FG>
|
|
class EliminationTree: public ClusterTree<FG> {
|
|
|
|
public:
|
|
|
|
// In an elimination tree, the clusters are called nodes
|
|
typedef typename ClusterTree<FG>::Cluster Node;
|
|
typedef typename Node::shared_ptr sharedNode;
|
|
|
|
// we typedef the following handy list of ordered factor graphs
|
|
typedef std::pair<Symbol, FG> NamedGraph;
|
|
typedef std::list<NamedGraph> OrderedGraphs;
|
|
|
|
private:
|
|
|
|
/** Number of variables */
|
|
size_t nrVariables_;
|
|
|
|
/** Map from ordering index to Nodes */
|
|
typedef std::vector<sharedNode> Nodes;
|
|
Nodes nodes_;
|
|
|
|
static inline Symbol getName(const NamedGraph& namedGraph) {
|
|
return namedGraph.first;
|
|
}
|
|
|
|
/**
|
|
* add a factor graph fragment with given frontal key into the tree. Assumes
|
|
* parent node was already added (will throw exception if not).
|
|
*/
|
|
void add(const FG& fg, const Symbol& key, const IndexTable<Symbol>& indexTable);
|
|
|
|
public:
|
|
|
|
/**
|
|
* Constructor variant 1: from an ordered list of factor graphs
|
|
* The list is supposed to be in elimination order, and for each
|
|
* eliminated variable a list of factors to be eliminated.
|
|
* This function assumes the input is correct (!) and will not check
|
|
* whether the factors refer only to the correct set of variables.
|
|
*/
|
|
EliminationTree(const OrderedGraphs& orderedGraphs);
|
|
|
|
/**
|
|
* Constructor variant 2: given a factor graph and the elimination ordering
|
|
*/
|
|
EliminationTree(FG& fg, const Ordering& ordering);
|
|
|
|
}; // EliminationTree
|
|
|
|
} // namespace gtsam
|