gtsam::GaussianFactorGraphSystem Class Reference

Detailed Description

Compiled flat-vector system used by preconditioned conjugate gradients.

Construction caches graph metadata and the right-hand side, compiles supported factors into flat execution plans, and retains a compatibility graph for other GaussianFactor implementations.

Note

Multiplication reuses mutable workspace and block-diagonal assembly is lazy. Concurrent calls on one instance, or on copies sharing the same implementation, require external synchronization.

Public Member Functions
	GaussianFactorGraphSystem (const GaussianFactorGraph &gfg, const Preconditioner &preconditioner, const KeyInfo &info, const std::map< Key, Vector > &lambda, bool parallel=true, size_t numThreads=0)
	Compile a Gaussian factor graph into a flat-vector PCG system.
void	residual (const Vector &x, Vector &r) const
	Overwrite r with the residual b - H*x in flat KeyInfo ordering.
void	multiply (const Vector &x, Vector &y) const
	Overwrite y with the Hessian-vector product H*x.
void	leftPrecondition (const Vector &x, Vector &y) const
	Overwrite y with the left split-preconditioner solve L^{-1}*x.
void	rightPrecondition (const Vector &x, Vector &y) const
	Overwrite y with the right split-preconditioner solve L^{-T}*x.
void	scal (const double alpha, Vector &x) const
	Scale x in place by alpha.
double	dot (const Vector &x, const Vector &y) const
	Return the Euclidean dot product of two flat vectors.
void	axpy (const double alpha, const Vector &x, Vector &y) const
	Accumulate alpha*x into y.
void	getb (Vector &b) const
	Overwrite b with the cached normal-equation right-hand side.
size_t	numThreads () const
	Return the effective worker count, or one for serial execution.

Friends
class	PCGSolver

Constructor & Destructor Documentation

GaussianFactorGraphSystem()

gtsam::GaussianFactorGraphSystem::GaussianFactorGraphSystem	(	const GaussianFactorGraph &	gfg,
		const Preconditioner &	preconditioner,
		const KeyInfo &	info,
		const std::map< Key, Vector > &	lambda,
		bool	parallel = true,
		size_t	numThreads = 0 )

Compile a Gaussian factor graph into a flat-vector PCG system.

Parallel execution is enabled by default for sufficiently large systems. Set parallel to false or numThreads to one for serial execution. A zero numThreads selects an automatically capped worker count.

Parameters

gfg	Gaussian factor graph to compile and retain as needed.
preconditioner	Built preconditioner used by split solves.
info	Ordering, dimensions, and scalar offsets for graph keys.
lambda	Per-key damping retained for API compatibility.
parallel	Whether large kernels may use the task scheduler.
numThreads	Requested worker count; zero selects automatically.

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

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