ug4
ug::CG< TVector > Class Template Reference

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

#include <cg.h>

+ Inheritance diagram for ug::CG< TVector >:

Public Types

typedef IPreconditionedLinearOperatorInverse< vector_typebase_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 = B*d and update defect d := d - A*c 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_typem_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
TVectorvector 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()

◆ enter_precond_debug_section()

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

◆ name()

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

◆ preconditioner() [1/2]

template<typename TVector >
SmartPtr<ILinearIterator<X, X> > ug::IPreconditionedLinearOperatorInverse< X >::preconditioner
inlineprotected

◆ 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

◆ 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

◆ write_debugXR()

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

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: