Detailed Description

template<class BAYESNET, class GRAPH>
class gtsam::EliminationTree< BAYESNET, GRAPH >

An elimination tree is a data structure used intermediately during elimination.

In future versions it will be used to save work between multiple eliminations.

When a variable is eliminated, a new factor is created by combining that variable's neighboring factors. The new combined factor involves the combined factors' involved variables. When the lowest-ordered one of those variables is eliminated, it consumes that combined factor. In the elimination tree, that lowest-ordered variable is the parent of the variable that was eliminated to produce the combined factor. This yields a tree in general, and not a chain because of the implicit sparse structure of the resulting Bayes net.

This structure is examined even more closely in a JunctionTree, which additionally identifies cliques in the chordal Bayes net.

Advanced Interface
class	::EliminationTreeTester
	Allow access to constructor and add methods for testing purposes.

	EliminationTree ()
	Protected default constructor.

const FastVector< sharedNode > &	roots () const
	Return the set of roots (one for a tree, multiple for a forest)

const FastVector< sharedFactor > &	remainingFactors () const
	Return the remaining factors that are not pulled into elimination.

void	swap (This &other)
	Swap the data of this tree with another one, this operation is very fast.

Standard Constructors
	EliminationTree (const FactorGraphType &factorGraph, const VariableIndex &structure, const Ordering &order)
	Build the elimination tree of a factor graph using pre-computed column structure. More...

	EliminationTree (const FactorGraphType &factorGraph, const Ordering &order)
	Build the elimination tree of a factor graph. More...

	EliminationTree (const This &other)
	Copy constructor - makes a deep copy of the tree structure, but only pointers to factors are copied, factors are not cloned.

This &	operator= (const This &other)
	Assignment operator - makes a deep copy of the tree structure, but only pointers to factors are copied, factors are not cloned.

Testable
bool	equals (const This &other, double tol=1e-9) const
	Test whether the tree is equal to another.

void	print (const std::string &name="EliminationTree: ", const KeyFormatter &formatter=DefaultKeyFormatter) const
	Print the tree to cout.

Standard Interface
std::pair< boost::shared_ptr< BayesNetType >, boost::shared_ptr< FactorGraphType > >	eliminate (Eliminate function) const
	Eliminate the factors to a Bayes net and remaining factor graph. More...

Public Types
typedef GRAPH	FactorGraphType
	The factor graph type.

typedef GRAPH::FactorType	FactorType
	The type of factors.

typedef boost::shared_ptr< FactorType >	sharedFactor
	Shared pointer to a factor.

typedef BAYESNET	BayesNetType
	The BayesNet corresponding to FACTOR.

typedef BayesNetType::ConditionalType	ConditionalType
	The type of conditionals.

typedef boost::shared_ptr< ConditionalType >	sharedConditional
	Shared pointer to a conditional.

typedef GRAPH::Eliminate	Eliminate

typedef boost::shared_ptr< Node >	sharedNode
	Shared pointer to Node.

Classes
struct	Node

Protected Types
typedef EliminationTree< BAYESNET, GRAPH >	This
	This class.

typedef boost::shared_ptr< This >	shared_ptr
	Shared pointer to this class.

Protected Attributes
FastVector< sharedNode >	roots_
	concept check

FastVector< sharedFactor >	remainingFactors_

Constructor & Destructor Documentation

◆ EliminationTree() [1/2]

template<class BAYESNET , class GRAPH >

gtsam::EliminationTree< BAYESNET, GRAPH >::EliminationTree	(	const FactorGraphType &	factorGraph,
		const VariableIndex &	structure,
		const Ordering &	order
	)

protected

Build the elimination tree of a factor graph using pre-computed column structure.

Parameters

factorGraph	The factor graph for which to build the elimination tree
structure	The set of factors involving each variable. If this is not precomputed, you can call the Create(const FactorGraph<DERIVEDFACTOR>&) named constructor instead.

Returns: The elimination tree

◆ EliminationTree() [2/2]

template<class BAYESNET , class GRAPH >

gtsam::EliminationTree< BAYESNET, GRAPH >::EliminationTree	(	const FactorGraphType &	factorGraph,
		const Ordering &	order
	)

protected

Build the elimination tree of a factor graph.

Note that this has to compute the column structure as a VariableIndex, so if you already have this precomputed, use the other constructor instead.

Parameters

factorGraph The factor graph for which to build the elimination tree

Member Function Documentation

◆ eliminate()

template<class BAYESNET , class GRAPH >

std::pair< boost::shared_ptr< BAYESNET >, boost::shared_ptr< GRAPH > > gtsam::EliminationTree< BAYESNET, GRAPH >::eliminate ( Eliminate function ) const

Eliminate the factors to a Bayes net and remaining factor graph.

Parameters

function The function to use to eliminate, see the namespace functions in GaussianFactorGraph.h

Returns: The Bayes net and factor graph resulting from elimination

The documentation for this class was generated from the following files:

/Users/dellaert/git/github/gtsam/inference/EliminationTree.h
/Users/dellaert/git/github/gtsam/inference/EliminationTree-inst.h

Detailed Description

Advanced Interface

Standard Constructors

Testable

Standard Interface

Public Types

Classes

Protected Types

Protected Attributes

Constructor & Destructor Documentation

◆ EliminationTree() [1/2]

◆ EliminationTree() [2/2]

Member Function Documentation

◆ eliminate()