#include <deal.II/matrix_free/operators.h>

Inheritance diagram for MatrixFreeOperators::MGInterfaceOperator< OperatorType >:

Public Types
using	value_type = typename OperatorType::value_type

using	size_type = typename OperatorType::size_type

Public Member Functions
	MGInterfaceOperator ()

void	clear ()

void	initialize (const OperatorType &operator_in)

template<typename VectorType >
void	vmult (VectorType &dst, const VectorType &src) const

template<typename VectorType >
void	Tvmult (VectorType &dst, const VectorType &src) const

template<typename VectorType >
void	initialize_dof_vector (VectorType &vec) const

Public Member Functions inherited from Subscriptor
	Subscriptor ()

	Subscriptor (const Subscriptor &)

	Subscriptor (Subscriptor &&) noexcept

virtual	~Subscriptor ()

Subscriptor &	operator= (const Subscriptor &)

Subscriptor &	operator= (Subscriptor &&) noexcept

void	subscribe (const char *identifier=nullptr) const

void	unsubscribe (const char *identifier=nullptr) const

unsigned int	n_subscriptions () const

template<typename StreamType >
void	list_subscribers (StreamType &stream) const

void	list_subscribers () const

template<class Archive >
void	serialize (Archive &ar, const unsigned int version)

Private Attributes
SmartPointer< const OperatorType >	mf_base_operator

Additional Inherited Members
Static Public Member Functions inherited from Subscriptor
static::ExceptionBase &	ExcInUse (int arg1, std::string arg2, std::string arg3)

static::ExceptionBase &	ExcNoSubscriber (std::string arg1, std::string arg2)

Detailed Description

template<typename OperatorType>
class MatrixFreeOperators::MGInterfaceOperator< OperatorType >

Auxiliary class to provide interface vmult/Tvmult methods required in adaptive geometric multgrids. OperatorType class should be derived from MatrixFreeOperators::Base class.

The adaptive multigrid realization in deal.II implements an approach called local smoothing. This means that the smoothing on the finest level only covers the local part of the mesh defined by the fixed (finest) grid level and ignores parts of the computational domain where the terminal cells are coarser than this level. As the method progresses to coarser levels, more and more of the global mesh will be covered. At some coarser level, the whole mesh will be covered. Since all level matrices in the multigrid method cover a single level in the mesh, no hanging nodes appear on the level matrices. At the interface between multigrid levels, homogeneous Dirichlet boundary conditions are set while smoothing. When the residual is transferred to the next coarser level, however, the coupling over the multigrid interface needs to be taken into account. This is done by the so-called interface (or edge) matrices that compute the part of the residual that is missed by the level matrix with homogeneous Dirichlet conditions. We refer to the Multigrid paper by Janssen and Kanschat for more details.

For the implementation of those interface matrices, most infrastructure is already in place and provided by MatrixFreeOperators::Base through the two multiplication routines vmult_interface_down() and vmult_interface_up(). The only thing MGInterfaceOperator does is wrapping those operations and make them accessible via vmult() and Tvmult interface as expected by the multigrid routines (that were originally written for matrices, hence expecting those names). Note that the vmult_interface_down is used during the restriction phase of the multigrid V-cycle, whereas vmult_interface_up is used during the prolongation phase.

Author: Martin Kronbichler, 2016

Definition at line 531 of file operators.h.