the CG method as a solver for linear operators More...

#include <cg.h>

Inheritance diagram for ug::CG< TVector >:

Public Types
typedef IPreconditionedLinearOperatorInverse< vector_type >	base_type
	Base type. More...

typedef TVector	vector_type
	Vector type. More...

Public Types inherited from ug::IPreconditionedLinearOperatorInverse< TVector >
typedef ILinearOperatorInverse< TVector, TVector >	base_type
	Base class. More...

typedef TVector	codomain_function_type
	Range space. More...

typedef TVector	domain_function_type
	Domain space. More...

Public Types inherited from ug::ILinearOperatorInverse< X, Y >
typedef Y	codomain_function_type
	Range space. More...

typedef X	domain_function_type
	Domain space. More...

Public Types inherited from ug::ILinearIterator< X, X >
typedef X	codomain_function_type
	Range space. More...

typedef X	domain_function_type
	Domain space. More...

Public Types inherited from ug::VectorDebugWritingObject< TVector >
typedef TVector	vector_type
	type of vector More...

Public Member Functions
void	add_postprocess_corr (SmartPtr< IPProcessVector< vector_type > > p)
	adds a post-process for the iterates More...

virtual bool	apply_return_defect (vector_type &x, vector_type &b)
	Solve J(u)*x = b, such that x = J(u)^{-1} b. More...

	CG ()
	constructors More...

	CG (SmartPtr< ILinearIterator< vector_type, vector_type > > spPrecond)

	CG (SmartPtr< ILinearIterator< vector_type, vector_type > > spPrecond, SmartPtr< IConvergenceCheck< vector_type > > spConvCheck)

virtual const char *	name () const
	name of solver More...

void	remove_postprocess_corr (SmartPtr< IPProcessVector< vector_type > > p)
	removes a post-process for the iterates More...

virtual bool	supports_parallel () const
	returns if parallel solving is supported More...

Public Member Functions inherited from ug::IPreconditionedLinearOperatorInverse< TVector >
virtual bool	apply (TVector &x, const TVector &b)
	compute new correction c = B*d More...

virtual std::string	config_string () const
	returns information about configuration parameters More...

std::string	config_string_preconditioner_convergence_check () const
	returns config information of convergence check and preconditioner More...

virtual bool	init (SmartPtr< ILinearOperator< TVector, TVector > > J, const TVector &u)
	initializes the solver for an operator More...

virtual bool	init (SmartPtr< ILinearOperator< TVector, TVector > > L)
	initializes the solver for an operator More...

	IPreconditionedLinearOperatorInverse ()
	Empty constructor. More...

	IPreconditionedLinearOperatorInverse (SmartPtr< ILinearIterator< TVector, TVector > > spPrecond)
	constructor setting the preconditioner More...

	IPreconditionedLinearOperatorInverse (SmartPtr< ILinearIterator< TVector, TVector > > spPrecond, SmartPtr< IConvergenceCheck< TVector > > spConvCheck)
	constructor setting the preconditioner More...

void	set_compute_fresh_defect_when_finished (bool bRecompute)
	for debug: computes norm again after whole calculation of apply More...

void	set_preconditioner (SmartPtr< ILinearIterator< TVector, TVector > > spPrecond)
	sets the preconditioner More...

SmartPtr< ILinearIterator< TVector, TVector > >	preconditioner ()

ConstSmartPtr< ILinearIterator< TVector, TVector > >	preconditioner () const

Public Member Functions inherited from ug::ILinearOperatorInverse< X, Y >
virtual bool	apply (Y &u, const X &f)=0
	applies inverse operator, i.e. returns u = A^{-1} f More...

virtual bool	apply_return_defect (Y &u, X &f)=0
	applies inverse operator, i.e. returns u = A^{-1} f and returns defect d := f - A*u More...

virtual bool	apply_update_defect (Y &u, X &f)

virtual SmartPtr< ILinearIterator< X, Y > >	clone ()
	clone More...

SmartPtr< IConvergenceCheck< X > >	convergence_check ()
	returns the convergence check More...

ConstSmartPtr< IConvergenceCheck< X > >	convergence_check () const
	returns the convergence check More...

number	defect () const
	returns the current defect More...

	ILinearOperatorInverse ()
	constructor setting convergence check to (100, 1e-12, 1e-12, true) More...

	ILinearOperatorInverse (SmartPtr< IConvergenceCheck< X > > spConvCheck)
	Default constructor. More...

virtual bool	init (SmartPtr< ILinearOperator< Y, X > > J, const Y &u)
	initializes for the inverse for a linearized operator at linearization point u More...

virtual bool	init (SmartPtr< ILinearOperator< Y, X > > L)
	initializes for the inverse for a linear operator More...

SmartPtr< ILinearOperator< Y, X > >	linear_operator ()
	returns the current Operator this Inverse Operator is initialized for More...

number	reduction () const
	returns the current relative reduction More...

void	set_convergence_check (SmartPtr< IConvergenceCheck< X > > spConvCheck)
	set the convergence check More...

virtual int	standard_offset () const
	returns the standard offset for output More...

int	step () const
	returns the current number of steps More...

virtual	~ILinearOperatorInverse ()
	virtual destructor More...

Public Member Functions inherited from ug::ILinearIterator< X, X >
virtual bool	apply (X &c, const X &d)=0
	compute new correction c = B*d More...

virtual bool	apply_update_defect (X &c, X &d)=0
	compute new correction c = Bd and update defect d := d - Ac More...

SmartPtr< IDamping< X, X > >	damping ()
	returns the scaling More...

	ILinearIterator ()
	constructor More...

	ILinearIterator (const ILinearIterator< X, X > &parent)
	copy constructor More...

virtual bool	init (SmartPtr< ILinearOperator< X, X > > J, const X &u)=0
	initialize for operator J(u) and linearization point u More...

virtual bool	init (SmartPtr< ILinearOperator< X, X > > L)=0
	initialize for linear operator L More...

void	set_damp (number factor)
	sets the damping to a constant factor More...

void	set_damp (SmartPtr< IDamping< X, X > > spScaling)
	sets a scaling for the correction More...

virtual	~ILinearIterator ()
	virtual destructor More...

Public Member Functions inherited from ug::VectorDebugWritingObject< TVector >
virtual void	set_debug (SmartPtr< IVectorDebugWriter< vector_type > > spDebugWriter)
	set debug writer More...

SmartPtr< IVectorDebugWriter< vector_type > >	vector_debug_writer ()
	returns the debug writer More...

ConstSmartPtr< IVectorDebugWriter< vector_type > >	vector_debug_writer () const

bool	vector_debug_writer_valid () const
	returns true if the debug writer is set More...

	VectorDebugWritingObject ()

	VectorDebugWritingObject (SmartPtr< IVectorDebugWriter< vector_type > > spDebugWriter)

void	write_debug (const vector_type &vec, const char *filename)
	writing debug output for a vector (if debug writer set) More...

virtual	~VectorDebugWritingObject ()
	virtual destructor More...

Protected Member Functions
void	enter_precond_debug_section (int loopCnt)
	debugger section for the preconditioner More...

SmartPtr< ILinearIterator< X, X > >	preconditioner ()

ConstSmartPtr< ILinearIterator< X, X > >	preconditioner () const

void	prepare_conv_check ()
	adjust output of convergence check More...

number	VecProd (vector_type &a, vector_type &b)

void	write_debugXR (vector_type &x, vector_type &r, int loopCnt)
	debugger output: solution and residual More...

Protected Member Functions inherited from ug::VectorDebugWritingObject< TVector >
void	enter_vector_debug_writer_section (const char *secDir)
	enters a debugging section More...

void	enter_vector_debug_writer_section (std::string secDir)
	enters a debugging section More...

void	leave_vector_debug_writer_section ()
	leaves a debugging section More...

void	print_debugger_message (const char *msg)
	prints a debugger message (listing all the sections) More...

void	print_debugger_message (std::string msg)
	prints a debugger message (listing all the sections) More...

virtual void	write_debug (const vector_type &vec, std::string name)
	writing debug output for a vector (if debug writer set) More...

Protected Attributes
PProcessChain< vector_type >	m_corr_post_process
	postprocessor for the correction in the iterations More...

Protected Attributes inherited from ug::IPreconditionedLinearOperatorInverse< TVector >
bool	m_bRecompute
	flag if fresh defect should be computed when finish for debug purpose More...

SmartPtr< ILinearIterator< TVector, TVector > >	m_spPrecond
	Iterator used in the iterative scheme to compute the correction and update the defect. More...

Protected Attributes inherited from ug::ILinearOperatorInverse< X, Y >
SmartPtr< IConvergenceCheck< X > >	m_spConvCheck
	smart pointer holding the convergence check More...

SmartPtr< ILinearOperator< Y, X > >	m_spLinearOperator
	Operator that is inverted by this Inverse Operator. More...

Protected Attributes inherited from ug::ILinearIterator< X, X >
SmartPtr< IDamping< X, X > >	m_spDamping
	the scaling More...

Protected Attributes inherited from ug::VectorDebugWritingObject< TVector >
SmartPtr< IVectorDebugWriter< vector_type > >	m_spVectorDebugWriter
	Debug Writer. More...

Detailed Description

template<typename TVector>
class ug::CG< TVector >

the CG method as a solver for linear operators

This class implements the CG - method for the solution of linear operator problems like A*x = b, where the solution x = A^{-1} b is computed.

For detailed description of the algorithm, please refer to:

Barrett, Berry, Chan, Demmel, Donatom Dongarra, Eijkhout, Pozo, Romine, Van der Vorst, "Templates for the Solution of Linear Systems: Building Blocks for Iterative Methods", p.13, Fig, 2.5
Saad, "Iterative Methods For Sparse Linear Systems", p277, Alg. 9.1

Template Parameters

TVector vector type

Member Typedef Documentation

◆ base_type

template<typename TVector >

typedef IPreconditionedLinearOperatorInverse<vector_type> ug::CG< TVector >::base_type

Base type.

◆ vector_type

template<typename TVector >

typedef TVector ug::CG< TVector >::vector_type

Vector type.

Constructor & Destructor Documentation

◆ CG() [1/3]

template<typename TVector >

ug::CG< TVector >::CG ( )

inline

constructors

◆ CG() [2/3]

template<typename TVector >

ug::CG< TVector >::CG ( SmartPtr< ILinearIterator< vector_type, vector_type > > spPrecond )

inline

◆ CG() [3/3]

template<typename TVector >

ug::CG< TVector >::CG	(	SmartPtr< ILinearIterator< vector_type, vector_type > >	spPrecond,
		SmartPtr< IConvergenceCheck< vector_type > >	spConvCheck
	)

inline

Member Function Documentation

◆ add_postprocess_corr()

template<typename TVector >

void ug::CG< TVector >::add_postprocess_corr ( SmartPtr< IPProcessVector< vector_type > > p )

inline

adds a post-process for the iterates

References ug::PProcessChain< TVector >::add(), ug::CG< TVector >::m_corr_post_process, and p.

◆ apply_return_defect()

template<typename TVector >

virtual bool ug::CG< TVector >::apply_return_defect	(	vector_type &	x,
		vector_type &	b
	)

inlinevirtual

◆ enter_precond_debug_section()

template<typename TVector >

void ug::CG< TVector >::enter_precond_debug_section ( int loopCnt )

inlineprotected

debugger section for the preconditioner

References ug::VectorDebugWritingObject< TVector >::enter_vector_debug_writer_section(), and ug::VectorDebugWritingObject< TVector >::vector_debug_writer_valid().

Referenced by ug::CG< TVector >::apply_return_defect().

◆ name()

template<typename TVector >

virtual const char* ug::CG< TVector >::name ( ) const

inlinevirtual

name of solver

Implements ug::ILinearOperatorInverse< X, Y >.

Referenced by ug::CG< TVector >::prepare_conv_check().

◆ preconditioner() [1/2]

template<typename TVector >

SmartPtr<ILinearIterator<X, X> > ug::IPreconditionedLinearOperatorInverse< X >::preconditioner

inlineprotected

returns the preconditioner

Referenced by ug::CG< TVector >::apply_return_defect(), ug::CG< TVector >::prepare_conv_check(), and ug::CG< TVector >::supports_parallel().

◆ preconditioner() [2/2]

template<typename TVector >

ConstSmartPtr<ILinearIterator<X, X> > ug::IPreconditionedLinearOperatorInverse< X >::preconditioner

inlineprotected

◆ prepare_conv_check()

template<typename TVector >

void ug::CG< TVector >::prepare_conv_check ( )

inlineprotected

adjust output of convergence check

References ug::ILinearOperatorInverse< X, Y >::convergence_check(), ug::CG< TVector >::name(), ug::CG< TVector >::preconditioner(), and s.

Referenced by ug::CG< TVector >::apply_return_defect().

◆ remove_postprocess_corr()

template<typename TVector >

void ug::CG< TVector >::remove_postprocess_corr ( SmartPtr< IPProcessVector< vector_type > > p )

inline

removes a post-process for the iterates

References ug::CG< TVector >::m_corr_post_process, p, and ug::PProcessChain< TVector >::remove().

◆ supports_parallel()

template<typename TVector >

virtual bool ug::CG< TVector >::supports_parallel ( ) const

inlinevirtual

returns if parallel solving is supported

Implements ug::ILinearOperatorInverse< X, Y >.

References ug::CG< TVector >::preconditioner().

◆ VecProd()

template<typename TVector >

number ug::CG< TVector >::VecProd	(	vector_type &	a,
		vector_type &	b
	)

inlineprotected

Referenced by ug::CG< TVector >::apply_return_defect().

◆ write_debugXR()

template<typename TVector >

void ug::CG< TVector >::write_debugXR	(	vector_type &	x,
		vector_type &	r,
		int	loopCnt
	)

inlineprotected

debugger output: solution and residual

References ug::VectorDebugWritingObject< TVector >::vector_debug_writer_valid(), and ug::VectorDebugWritingObject< TVector >::write_debug().

Referenced by ug::CG< TVector >::apply_return_defect().

Member Data Documentation

◆ m_corr_post_process

template<typename TVector >

PProcessChain<vector_type> ug::CG< TVector >::m_corr_post_process

protected

postprocessor for the correction in the iterations

These postprocess operations are applied to the preconditioned defect before the orthogonalization. The goal is to prevent the useless kernel parts to prevail in the (floating point) arithmetics.

Referenced by ug::CG< TVector >::add_postprocess_corr(), ug::CG< TVector >::apply_return_defect(), and ug::CG< TVector >::remove_postprocess_corr().

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

ugbase/lib_algebra/operator/linear_solver/cg.h

Public Types

Public Member Functions

Protected Member Functions

Protected Attributes

Detailed Description

template<typename TVector> class ug::CG< TVector >

Member Typedef Documentation

◆ base_type

◆ vector_type

Constructor & Destructor Documentation

◆ CG() [1/3]

◆ CG() [2/3]

◆ CG() [3/3]

Member Function Documentation

◆ add_postprocess_corr()

◆ apply_return_defect()

◆ enter_precond_debug_section()

◆ name()

◆ preconditioner() [1/2]

◆ preconditioner() [2/2]

◆ prepare_conv_check()

◆ remove_postprocess_corr()

◆ supports_parallel()

◆ VecProd()

◆ write_debugXR()

Member Data Documentation

◆ m_corr_post_process

template<typename TVector>
class ug::CG< TVector >