Detailed Description

Imperative multifrontal clique structure used by MultifrontalSolver.

Public Member Functions
	MultifrontalClique (std::vector< size_t > factorIndices, const std::weak_ptr< MultifrontalClique > &parent, const KeyVector &frontals, const KeySet &separatorKeys, const KeyDimMap &dims, size_t vbmRows, VectorValues solution, const std::unordered_set< Key > fixedKeys, size_t numEliminatedFrontals)
	Construct a clique from factor indices and cache static structure.
Setup (non-const)
void	finalize (std::vector< ChildInfo > children, const MultifrontalParameters &params)
	Cache the children list, compute parent indices, and lock in QR usage.
void	fillAb (const GaussianFactorGraph &graph)
	Load factor values into a lazily allocated, reusable Ab matrix.
void	prepareForElimination ()
	Zero out the info matrix, re-add Hessians, accumulate Jacobians and children.
void	factorize ()
	Perform Cholesky factorization on the frontal block.
void	addIdentityDamping (double lambda)
	Add identity damping to the frontal block.
void	addDiagonalDamping (double lambda, double minDiagonal, double maxDiagonal)
	Add diagonal damping to the frontal block.
void	addExactDiagonalDamping (double lambda, const VectorValues &hessianDiagonal, double minDiagonal, double maxDiagonal)
	Add diagonal damping to the frontal block using an externally provided Hessian diagonal diag(J^T J) keyed by variable.
Read-only methods
int	problemSize () const
	Return the clique dimension used for traversal scheduling.
size_t	numFrontals () const
	Return the number of frontal keys in this clique.
bool	fullyEliminated () const
	Return whether every symbolic frontal in this clique is eliminated.
const KeyVector &	orderedKeys () const
	Return keys ordered by block index (frontals followed by separators).
std::shared_ptr< GaussianConditional >	conditional () const
	Build a GaussianConditional from the in-place factorization.
std::shared_ptr< HessianFactor >	remainingFactor () const
	Build the assembled factor on variables retained after partial elimination.
const VerticalBlockMatrix &	Ab () const
	Get the vertical block matrix Ab.
const SymmetricBlockMatrix &	info () const
	Get the information matrix (const).
bool	useQR () const
	Check if this clique is using QR elimination.
bool	useCompactCholesky () const
	Check if this leaf avoids materializing its separator Hessian.
void	print (const std::string &s="", const KeyFormatter &keyFormatter=DefaultKeyFormatter) const
	Print this clique.
Solve (non-const)
void	eliminateInPlace ()
	Eliminate in-place, invalidating Ab_, and updating RSd_ and info_.
void	eliminateInPlace (double lambda, const LMDampingParams &dampingParams, const VectorValues &exactHessianDiagonal)
	Version of eliminate that applies damping before eliminate.
void	updateSolution ()
	Solve for this clique's frontal variables and write them back to the cached solution vectors.
double	lastOldError () const
	Access the last old error computed during updateSolution().
double	lastNewError () const
	Access the last new error computed during updateSolution().
double	constantTermError () const
	Return the constant error term for this clique (nonzero for roots).

Public Attributes
std::weak_ptr< MultifrontalClique >	parent
	Parent clique.
Children	children
	Child cliques used for traversal.
size_t	frontalDim = 0
	Frontal dimension.
size_t	separatorDim = 0
	Separator dimension.

Public Types
using	shared_ptr = std::shared_ptr<MultifrontalClique>
using	Children = std::vector<shared_ptr>

Classes
struct	ChildInfo

Friends
std::ostream &	operator<< (std::ostream &os, const MultifrontalClique &clique)

Constructor & Destructor Documentation

◆ MultifrontalClique()

gtsam::MultifrontalClique::MultifrontalClique	(	std::vector< size_t >	factorIndices,
		const std::weak_ptr< MultifrontalClique > &	parent,
		const KeyVector &	frontals,
		const KeySet &	separatorKeys,
		const KeyDimMap &	dims,
		size_t	vbmRows,
		VectorValues *	solution,
		const std::unordered_set< Key > *	fixedKeys,
		size_t	numEliminatedFrontals )

explicit

Construct a clique from factor indices and cache static structure.

Parameters

factorIndices	Indices of factors associated with this clique.
parent	Weak pointer to the parent clique.
frontals	Frontal keys for this clique.
separatorKeys	Separator keys for this clique.
dims	Key->dimension map.
vbmRows	Number of rows needed for the vertical block matrix.
solution	Solution storage for cached pointers.
fixedKeys	Keys fixed to zero by constraints (may be null).

Member Function Documentation

◆ addDiagonalDamping()

void gtsam::MultifrontalClique::addDiagonalDamping	(	double	lambda,
		double	minDiagonal,
		double	maxDiagonal )

Add diagonal damping to the frontal block.

Parameters

lambda	Damping factor
minDiagonal	Minimum diagonal value
maxDiagonal	Maximum diagonal value

◆ addExactDiagonalDamping()

void gtsam::MultifrontalClique::addExactDiagonalDamping	(	double	lambda,
		const VectorValues &	hessianDiagonal,
		double	minDiagonal,
		double	maxDiagonal )

Add diagonal damping to the frontal block using an externally provided Hessian diagonal diag(J^T J) keyed by variable.

This matches the legacy LM diagonal damping definition based on the diagonal of the original linearized system rather than the post-Schur clique information matrix.

Parameters

lambda	Damping factor
hessianDiagonal	Map from key to diagonal vector (dimension-matched).
minDiagonal	Minimum diagonal value
maxDiagonal	Maximum diagonal value

◆ addIdentityDamping()

void gtsam::MultifrontalClique::addIdentityDamping ( double lambda )

Add identity damping to the frontal block.

Parameters

lambda Damping factor

◆ eliminateInPlace() [1/2]

void gtsam::MultifrontalClique::eliminateInPlace ( )

Eliminate in-place, invalidating Ab_, and updating RSd_ and info_.

Computes the local information matrix from the stacked Jacobian (Ab), incorporates child separator contributions, and performs partial QR or Cholesky on the frontal blocks.

◆ eliminateInPlace() [2/2]

void gtsam::MultifrontalClique::eliminateInPlace	(	double	lambda,
		const LMDampingParams &	dampingParams,
		const VectorValues &	exactHessianDiagonal )

Version of eliminate that applies damping before eliminate.

Parameters

lambda	Optional damping value; non-positive disables damping.
dampingParams	Parameters controlling LM-style damping.
exactHessianDiagonal	diag(J^T J) values for diagonal damping.

◆ fillAb()

void gtsam::MultifrontalClique::fillAb ( const GaussianFactorGraph & graph )

Load factor values into a lazily allocated, reusable Ab matrix.

Parameters

graph The factor graph with updated values (structure must match the graph used to build this clique, apart from updated numerical values). Only JacobianFactor and BatchJacobianFactor inputs are supported.

◆ finalize()

void gtsam::MultifrontalClique::finalize	(	std::vector< ChildInfo >	children,
		const MultifrontalParameters &	params )

Cache the children list, compute parent indices, and lock in QR usage.

Parameters

children	Child cliques plus separator metadata.
params	Parameters controlling QR mode and thresholds.

◆ print()

void gtsam::MultifrontalClique::print	(	const std::string &	s = "",
		const KeyFormatter &	keyFormatter = DefaultKeyFormatter ) const

Print this clique.

Parameters

s	Optional string prefix.
keyFormatter	Ignored; retained for API compatibility.

◆ remainingFactor()

std::shared_ptr< HessianFactor > gtsam::MultifrontalClique::remainingFactor ( ) const

Build the assembled factor on variables retained after partial elimination.

The returned factor owns its information because it may outlive this clique. Consequently, exporting requires one copy of the active upper-triangular block. The clique must have been prepared, and any leading eliminated frontals must have been factorized.

◆ updateSolution()

void gtsam::MultifrontalClique::updateSolution ( )

Solve for this clique's frontal variables and write them back to the cached solution vectors.

Uses block back-substitution using the upper triangular-part of the Cholesky-stored information matrix, solving the triangular system for the frontal blocks.

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

/tmp/gtsam-4.3.0-doxygen.rsXPUS/source/gtsam/linear/MultifrontalClique.h
/tmp/gtsam-4.3.0-doxygen.rsXPUS/source/gtsam/linear/MultifrontalClique.cpp

Detailed Description

Public Member Functions

Public Attributes

Public Types

Classes

Friends

Constructor & Destructor Documentation

◆ MultifrontalClique()

Member Function Documentation

◆ addDiagonalDamping()

◆ addExactDiagonalDamping()

◆ addIdentityDamping()

◆ eliminateInPlace() [1/2]

◆ eliminateInPlace() [2/2]

◆ fillAb()

◆ finalize()

◆ print()

◆ remainingFactor()

◆ updateSolution()