Detailed Description

template<typename BayesTree>
class gtsam::BayesTreeMarginalizationHelper< BayesTree >

This class provides helper functions for marginalizing variables from a Bayes Tree.

Static Public Member Functions
static std::unordered_set< Key >	gatherAdditionalKeysToReEliminate (const BayesTree &bayesTree, const KeyVector &marginalizableKeys)
	This function identifies variables that need to be re-eliminated before performing marginalization.

Public Types
using	Clique = typename BayesTree::Clique
using	sharedClique = typename BayesTree::sharedClique

Classes
struct	CachedSearch
	A struct to cache the results of the below two functions. More...

Static Protected Member Functions
static std::unordered_set< const Clique * >	gatherAdditionalCliquesToReEliminate (const BayesTree &bayesTree, const KeyVector &marginalizableKeys)
	This function identifies cliques that need to be re-eliminated before performing marginalization.
static std::unordered_set< const Clique * >	getCliquesContainingKeys (const BayesTree &bayesTree, const std::unordered_set< Key > &keysOfInterest)
	Gather the cliques containing any of the given keys.
static bool	isWholeCliqueMarginalizable (const Clique clique, const std::unordered_set< Key > &marginalizableKeys, CachedSearch cache)
	Check if all variables in the clique are marginalizable.
static bool	isWholeSubtreeMarginalizable (const Clique subtree, const std::unordered_set< Key > &marginalizableKeys, CachedSearch cache)
	Check if all variables in the subtree are marginalizable.
static bool	needsReelimination (const Clique clique, const std::unordered_set< Key > &marginalizableKeys, CachedSearch cache)
	Check if a clique contains variables that need reelimination due to elimination ordering conflicts.
static void	gatherDependentCliques (const Clique rootClique, const std::unordered_set< Key > &marginalizableKeys, std::unordered_set< const Clique > additionalCliques, CachedSearch cache)
	Gather all dependent nodes that lie on a path from the root clique to a clique containing a non-marginalizable variable at the leaf side.
static void	gatherDependentCliquesFromChildren (const std::vector< const Clique * > &dependentChildren, const std::unordered_set< Key > &marginalizableKeys, std::unordered_set< const Clique * > additionalCliques, CachedSearch cache)
	A helper function for the above gatherDependentCliques().
static void	addCliqueToKeySet (const Clique clique, std::unordered_set< Key > additionalKeys)
	Add all frontal variables from a clique to a key set.
static bool	hasDependency (const Clique *clique, Key key)
	Check if the clique depends on the given key.
static bool	hasDependency (const Clique *clique, const std::unordered_set< Key > &keys)
	Check if the clique depends on any of the given keys.

Member Function Documentation

◆ addCliqueToKeySet()

template<typename BayesTree>

void gtsam::BayesTreeMarginalizationHelper< BayesTree >::addCliqueToKeySet	(	const Clique *	clique,
		std::unordered_set< Key > *	additionalKeys )

inlinestaticprotected

Add all frontal variables from a clique to a key set.

Parameters

[in]	clique	Clique to add keys from
[out]	additionalKeys	Pointer to the output key set

◆ gatherAdditionalCliquesToReEliminate()

template<typename BayesTree>

std::unordered_set< const Clique * > gtsam::BayesTreeMarginalizationHelper< BayesTree >::gatherAdditionalCliquesToReEliminate	(	const BayesTree &	bayesTree,
		const KeyVector &	marginalizableKeys )

inlinestaticprotected

This function identifies cliques that need to be re-eliminated before performing marginalization.

See the docstring of gatherAdditionalKeysToReEliminate().

◆ gatherAdditionalKeysToReEliminate()

template<typename BayesTree>

std::unordered_set< Key > gtsam::BayesTreeMarginalizationHelper< BayesTree >::gatherAdditionalKeysToReEliminate	(	const BayesTree &	bayesTree,
		const KeyVector &	marginalizableKeys )

inlinestatic

This function identifies variables that need to be re-eliminated before performing marginalization.

Re-elimination is necessary for a clique containing marginalizable variables if:

Some non-marginalizable variables appear before marginalizable ones in that clique;
Or it has a child node depending on a marginalizable variable AND the subtree rooted at that child contains non-marginalizables.

In addition, for any descendant node depending on a marginalizable variable, if the subtree rooted at that descendant contains non-marginalizable variables (i.e., it lies on a path from one of the aforementioned cliques that require re-elimination to a node containing non-marginalizable variables at the leaf side), then it also needs to be re-eliminated.

Parameters

[in]	bayesTree	The Bayes tree
[in]	marginalizableKeys	Keys to be marginalized

Returns: Set of additional keys that need to be re-eliminated

◆ gatherDependentCliques()

template<typename BayesTree>

void gtsam::BayesTreeMarginalizationHelper< BayesTree >::gatherDependentCliques	(	const Clique *	rootClique,
		const std::unordered_set< Key > &	marginalizableKeys,
		std::unordered_set< const Clique * > *	additionalCliques,
		CachedSearch *	cache )

inlinestaticprotected

Gather all dependent nodes that lie on a path from the root clique to a clique containing a non-marginalizable variable at the leaf side.

Parameters

[in]	rootClique	The root clique
[in]	marginalizableKeys	Set of keys to be marginalized

◆ getCliquesContainingKeys()

template<typename BayesTree>

std::unordered_set< const Clique * > gtsam::BayesTreeMarginalizationHelper< BayesTree >::getCliquesContainingKeys	(	const BayesTree &	bayesTree,
		const std::unordered_set< Key > &	keysOfInterest )

inlinestaticprotected

Gather the cliques containing any of the given keys.

Parameters

[in]	bayesTree	The Bayes tree
[in]	keysOfInterest	Set of keys of interest

Returns: Set of cliques that contain any of the given keys

◆ hasDependency()

template<typename BayesTree>

bool gtsam::BayesTreeMarginalizationHelper< BayesTree >::hasDependency	(	const Clique *	clique,
		Key	key )

inlinestaticprotected

Check if the clique depends on the given key.

Parameters

[in]	clique	Clique to check
[in]	key	Key to check for dependencies

Returns: true if clique depends on the key

◆ isWholeCliqueMarginalizable()

template<typename BayesTree>

bool gtsam::BayesTreeMarginalizationHelper< BayesTree >::isWholeCliqueMarginalizable	(	const Clique *	clique,
		const std::unordered_set< Key > &	marginalizableKeys,
		CachedSearch *	cache )

inlinestaticprotected

Check if all variables in the clique are marginalizable.

Note we use a cache map to avoid repeated searches.

◆ isWholeSubtreeMarginalizable()

template<typename BayesTree>

bool gtsam::BayesTreeMarginalizationHelper< BayesTree >::isWholeSubtreeMarginalizable	(	const Clique *	subtree,
		const std::unordered_set< Key > &	marginalizableKeys,
		CachedSearch *	cache )

inlinestaticprotected

Check if all variables in the subtree are marginalizable.

Note we use a cache map to avoid repeated searches.

◆ needsReelimination()

template<typename BayesTree>

bool gtsam::BayesTreeMarginalizationHelper< BayesTree >::needsReelimination	(	const Clique *	clique,
		const std::unordered_set< Key > &	marginalizableKeys,
		CachedSearch *	cache )

inlinestaticprotected

Check if a clique contains variables that need reelimination due to elimination ordering conflicts.

Parameters

[in]	clique	The clique to check
[in]	marginalizableKeys	Set of keys to be marginalized

Returns: true if any variables in the clique need re-elimination

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

/tmp/gtsam-4.3.0-doxygen.rsXPUS/source/gtsam/nonlinear/BayesTreeMarginalizationHelper.h

Detailed Description

Static Public Member Functions

Public Types

Classes

Static Protected Member Functions

Member Function Documentation

◆ addCliqueToKeySet()

◆ gatherAdditionalCliquesToReEliminate()

◆ gatherAdditionalKeysToReEliminate()

◆ gatherDependentCliques()

◆ getCliquesContainingKeys()

◆ hasDependency()

◆ isWholeCliqueMarginalizable()

◆ isWholeSubtreeMarginalizable()

◆ needsReelimination()