#include <deal.II/multigrid/mg_transfer_matrix_free.h>

Inheritance diagram for MGTransferMatrixFree< dim, Number >:

Public Member Functions
	MGTransferMatrixFree ()

	MGTransferMatrixFree (const MGConstrainedDoFs &mg_constrained_dofs)

virtual	~MGTransferMatrixFree () override=default

void	initialize_constraints (const MGConstrainedDoFs &mg_constrained_dofs)

void	clear ()

void	build (const DoFHandler< dim, dim > &dof_handler, const std::vector< std::shared_ptr< const Utilities::MPI::Partitioner >> &external_partitioners=std::vector< std::shared_ptr< const Utilities::MPI::Partitioner >>())

virtual void	prolongate (const unsigned int to_level, LinearAlgebra::distributed::Vector< Number > &dst, const LinearAlgebra::distributed::Vector< Number > &src) const override

virtual void	restrict_and_add (const unsigned int from_level, LinearAlgebra::distributed::Vector< Number > &dst, const LinearAlgebra::distributed::Vector< Number > &src) const override

template<typename Number2 , int spacedim>
void	interpolate_to_mg (const DoFHandler< dim, spacedim > &dof_handler, MGLevelObject< LinearAlgebra::distributed::Vector< Number >> &dst, const LinearAlgebra::distributed::Vector< Number2 > &src) const

std::size_t	memory_consumption () const

Public Member Functions inherited from MGLevelGlobalTransfer< LinearAlgebra::distributed::Vector< Number > >
void	clear ()

template<int dim, typename Number2 , int spacedim>
void	copy_to_mg (const DoFHandler< dim, spacedim > &dof_handler, MGLevelObject< LinearAlgebra::distributed::Vector< Number >> &dst, const LinearAlgebra::distributed::Vector< Number2 > &src) const

template<int dim, typename Number2 , int spacedim>
void	copy_from_mg (const DoFHandler< dim, spacedim > &dof_handler, LinearAlgebra::distributed::Vector< Number2 > &dst, const MGLevelObject< LinearAlgebra::distributed::Vector< Number >> &src) const

template<int dim, typename Number2 , int spacedim>
void	copy_from_mg_add (const DoFHandler< dim, spacedim > &dof_handler, LinearAlgebra::distributed::Vector< Number2 > &dst, const MGLevelObject< LinearAlgebra::distributed::Vector< Number >> &src) const

void	set_component_to_block_map (const std::vector< unsigned int > &map)

std::size_t	memory_consumption () const

void	print_indices (std::ostream &os) const

Public Member Functions inherited from MGTransferBase< LinearAlgebra::distributed::Vector< Number > >
virtual	~MGTransferBase () override=default

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 (std::atomic< bool > *const validity, const std::string &identifier="") const

void	unsubscribe (std::atomic< bool > *const validity, const std::string &identifier="") 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)

Static Public Member Functions
static ::ExceptionBase &	ExcNoProlongation ()

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)

Private Member Functions
template<int degree>
void	do_prolongate_add (const unsigned int to_level, LinearAlgebra::distributed::Vector< Number > &dst, const LinearAlgebra::distributed::Vector< Number > &src) const

template<int degree>
void	do_restrict_add (const unsigned int from_level, LinearAlgebra::distributed::Vector< Number > &dst, const LinearAlgebra::distributed::Vector< Number > &src) const

Private Attributes
unsigned int	fe_degree

bool	element_is_continuous

unsigned int	n_components

unsigned int	n_child_cell_dofs

std::vector< std::vector< unsigned int > >	level_dof_indices

std::vector< std::vector< std::pair< unsigned int, unsigned int > > >	parent_child_connect

std::vector< unsigned int >	n_owned_level_cells

AlignedVector< VectorizedArray< Number > >	prolongation_matrix_1d

AlignedVector< VectorizedArray< Number > >	evaluation_data

std::vector< AlignedVector< VectorizedArray< Number > > >	weights_on_refined

std::vector< std::vector< std::vector< unsigned short > > >	dirichlet_indices

MGLevelObject< std::shared_ptr< const Utilities::MPI::Partitioner > >	vector_partitioners

Additional Inherited Members
Protected Member Functions inherited from MGLevelGlobalTransfer< LinearAlgebra::distributed::Vector< Number > >
template<int dim, typename Number2 , int spacedim>
void	copy_to_mg (const DoFHandler< dim, spacedim > &dof_handler, MGLevelObject< LinearAlgebra::distributed::Vector< Number >> &dst, const LinearAlgebra::distributed::Vector< Number2 > &src, const bool solution_transfer) const

template<int dim, int spacedim>
void	fill_and_communicate_copy_indices (const DoFHandler< dim, spacedim > &dof_handler)

Protected Attributes inherited from MGLevelGlobalTransfer< LinearAlgebra::distributed::Vector< Number > >
std::vector< types::global_dof_index >	sizes

std::vector< Table< 2, unsigned int > >	copy_indices

std::vector< Table< 2, unsigned int > >	solution_copy_indices

std::vector< Table< 2, unsigned int > >	copy_indices_global_mine

std::vector< Table< 2, unsigned int > >	solution_copy_indices_global_mine

std::vector< Table< 2, unsigned int > >	copy_indices_level_mine

std::vector< Table< 2, unsigned int > >	solution_copy_indices_level_mine

bool	perform_plain_copy

bool	perform_renumbered_plain_copy

std::vector< unsigned int >	component_to_block_map

SmartPointer< const MGConstrainedDoFs, MGLevelGlobalTransfer< LinearAlgebra::distributed::Vector< Number > > >	mg_constrained_dofs

LinearAlgebra::distributed::Vector< Number >	ghosted_global_vector

LinearAlgebra::distributed::Vector< Number >	solution_ghosted_global_vector

MGLevelObject< LinearAlgebra::distributed::Vector< Number > >	ghosted_level_vector

MGLevelObject< LinearAlgebra::distributed::Vector< Number > >	solution_ghosted_level_vector

Detailed Description

template<int dim, typename Number>
class MGTransferMatrixFree< dim, Number >

Implementation of the MGTransferBase interface for which the transfer operations is implemented in a matrix-free way based on the interpolation matrices of the underlying finite element. This requires considerably less memory than MGTransferPrebuilt and can also be considerably faster than that variant.

This class currently only works for tensor-product finite elements based on FE_Q and FE_DGQ elements, including systems involving multiple components of one of these elements. Systems with different elements or other elements are currently not implemented.

Author: Martin Kronbichler

Date: 2016

Definition at line 57 of file mg_transfer_matrix_free.h.

Constructor & Destructor Documentation

◆ MGTransferMatrixFree() [1/2]

template<int dim, typename Number >

MGTransferMatrixFree< dim, Number >::MGTransferMatrixFree

Constructor without constraint matrices. Use this constructor only with discontinuous finite elements or with no local refinement.

Definition at line 43 of file mg_transfer_matrix_free.cc.

◆ MGTransferMatrixFree() [2/2]

template<int dim, typename Number >

MGTransferMatrixFree< dim, Number >::MGTransferMatrixFree ( const MGConstrainedDoFs & mg_constrained_dofs )

Constructor with constraints. Equivalent to the default constructor followed by initialize_constraints().

Definition at line 53 of file mg_transfer_matrix_free.cc.

◆ ~MGTransferMatrixFree()

template<int dim, typename Number >

virtual MGTransferMatrixFree< dim, Number >::~MGTransferMatrixFree ( )

overridevirtualdefault

Destructor.

Member Function Documentation

◆ initialize_constraints()

template<int dim, typename Number >

void MGTransferMatrixFree< dim, Number >::initialize_constraints ( const MGConstrainedDoFs & mg_constrained_dofs )

Initialize the constraints to be used in build().

Definition at line 67 of file mg_transfer_matrix_free.cc.

◆ clear()

template<int dim, typename Number >

void MGTransferMatrixFree< dim, Number >::clear

Reset the object to the state it had right after the default constructor.

Definition at line 77 of file mg_transfer_matrix_free.cc.

◆ build()

template<int dim, typename Number >

void MGTransferMatrixFree< dim, Number >::build	(	const DoFHandler< dim, dim > &	dof_handler,
		const std::vector< std::shared_ptr< const Utilities::MPI::Partitioner >> &	external_partitioners = `std::vector<std::shared_ptr<const Utilities::MPI::Partitioner>>()`
	)

Actually build the information for the prolongation for each level.

The optional second argument of external partitioners allows the user to suggest vector partitioning on the levels. In case the partitioners are found to contain all ghost unknowns that are visited through the transfer, the given partitioners are chosen. This ensures compatibility of vectors during prolongate and restrict with external partitioners as given by the user, which in turn saves some copy operations. However, in case there are unknowns missing – and this is typically the case at some point during h-coarsening since processors will need to drop out and thus children's unknowns on some processor will be needed as ghosts to a parent cell on another processor – the provided external partitioners are ignored and internal variants are used instead.

Definition at line 97 of file mg_transfer_matrix_free.cc.

◆ prolongate()

template<int dim, typename Number >

void MGTransferMatrixFree< dim, Number >::prolongate	(	const unsigned int	to_level,
		LinearAlgebra::distributed::Vector< Number > &	dst,
		const LinearAlgebra::distributed::Vector< Number > &	src
	)		const

overridevirtual

Prolongate a vector from level to_level-1 to level to_level using the embedding matrices of the underlying finite element. The previous content of dst is overwritten.

Parameters

to_level	The index of the level to prolongate to, which is the level of `dst`.
src	is a vector with as many elements as there are degrees of freedom on the coarser level involved.
dst	has as many elements as there are degrees of freedom on the finer level.

Implements MGTransferBase< LinearAlgebra::distributed::Vector< Number > >.

Definition at line 183 of file mg_transfer_matrix_free.cc.

◆ restrict_and_add()

template<int dim, typename Number >

void MGTransferMatrixFree< dim, Number >::restrict_and_add	(	const unsigned int	from_level,
		LinearAlgebra::distributed::Vector< Number > &	dst,
		const LinearAlgebra::distributed::Vector< Number > &	src
	)		const

overridevirtual

Restrict a vector from level from_level to level from_level-1 using the transpose operation of the prolongate() method. If the region covered by cells on level from_level is smaller than that of level from_level-1 (local refinement), then some degrees of freedom in dst are active and will not be altered. For the other degrees of freedom, the result of the restriction is added.

Parameters

from_level	The index of the level to restrict from, which is the level of `src`.
src	is a vector with as many elements as there are degrees of freedom on the finer level involved.
dst	has as many elements as there are degrees of freedom on the coarser level.

Implements MGTransferBase< LinearAlgebra::distributed::Vector< Number > >.

Definition at line 264 of file mg_transfer_matrix_free.cc.

◆ interpolate_to_mg()

template<int dim, typename Number >

template<typename Number2 , int spacedim>

void MGTransferMatrixFree< dim, Number >::interpolate_to_mg	(	const DoFHandler< dim, spacedim > &	dof_handler,
		MGLevelObject< LinearAlgebra::distributed::Vector< Number >> &	dst,
		const LinearAlgebra::distributed::Vector< Number2 > &	src
	)		const

Restrict fine-mesh field src to each multigrid level in dof_handler and store the result in dst.

The argument dst has to be initialized with the correct size according to the number of levels of the triangulation.

If an inner vector of dst is empty or has incorrect locally owned size, it will be resized to locally relevant degrees of freedom on each level.

◆ memory_consumption()

template<int dim, typename Number >

std::size_t MGTransferMatrixFree< dim, Number >::memory_consumption

Memory used by this object.

Definition at line 639 of file mg_transfer_matrix_free.cc.

◆ do_prolongate_add()

template<int dim, typename Number >

template<int degree>

void MGTransferMatrixFree< dim, Number >::do_prolongate_add	(	const unsigned int	to_level,
		LinearAlgebra::distributed::Vector< Number > &	dst,
		const LinearAlgebra::distributed::Vector< Number > &	src
	)		const

private

Perform the prolongation operation.

Definition at line 377 of file mg_transfer_matrix_free.cc.

◆ do_restrict_add()

template<int dim, typename Number >

template<int degree>

void MGTransferMatrixFree< dim, Number >::do_restrict_add	(	const unsigned int	from_level,
		LinearAlgebra::distributed::Vector< Number > &	dst,
		const LinearAlgebra::distributed::Vector< Number > &	src
	)		const

private

Performs the restriction operation.

Definition at line 516 of file mg_transfer_matrix_free.cc.

Member Data Documentation

◆ fe_degree

template<int dim, typename Number >

unsigned int MGTransferMatrixFree< dim, Number >::fe_degree

private

A variable storing the degree of the finite element contained in the DoFHandler passed to build(). The selection of the computational kernel is based on this number.

Definition at line 189 of file mg_transfer_matrix_free.h.

◆ element_is_continuous

template<int dim, typename Number >

bool MGTransferMatrixFree< dim, Number >::element_is_continuous

private

A variable storing whether the element is continuous and there is a joint degree of freedom in the center of the 1D line.

Definition at line 195 of file mg_transfer_matrix_free.h.

◆ n_components

template<int dim, typename Number >

unsigned int MGTransferMatrixFree< dim, Number >::n_components

private

A variable storing the number of components in the finite element contained in the DoFHandler passed to build().

Definition at line 201 of file mg_transfer_matrix_free.h.

◆ n_child_cell_dofs

template<int dim, typename Number >

unsigned int MGTransferMatrixFree< dim, Number >::n_child_cell_dofs

private

A variable storing the number of degrees of freedom on all child cells. It is 2^dim*fe.dofs_per_cell for DG elements and somewhat less for continuous elements.

Definition at line 208 of file mg_transfer_matrix_free.h.

◆ level_dof_indices

template<int dim, typename Number >

std::vector<std::vector<unsigned int> > MGTransferMatrixFree< dim, Number >::level_dof_indices

private

This variable holds the indices for cells on a given level, extracted from DoFHandler for fast access. All DoF indices on a given level are stored as a plain array (since this class assumes constant DoFs per cell). To index into this array, use the cell number times dofs_per_cell.

This array first is arranged such that all locally owned level cells come first (found in the variable n_owned_level_cells) and then other cells necessary for the transfer to the next level.

Definition at line 220 of file mg_transfer_matrix_free.h.

◆ parent_child_connect

template<int dim, typename Number >

std::vector<std::vector<std::pair<unsigned int, unsigned int> > > MGTransferMatrixFree< dim, Number >::parent_child_connect

private

A variable storing the connectivity from parent to child cell numbers for each level.

Definition at line 227 of file mg_transfer_matrix_free.h.

◆ n_owned_level_cells

template<int dim, typename Number >

std::vector<unsigned int> MGTransferMatrixFree< dim, Number >::n_owned_level_cells

private

A variable storing the number of cells owned on a given process (sets the bounds for the worker loops) for each level.

Definition at line 233 of file mg_transfer_matrix_free.h.

◆ prolongation_matrix_1d

template<int dim, typename Number >

AlignedVector<VectorizedArray<Number> > MGTransferMatrixFree< dim, Number >::prolongation_matrix_1d

private

This variable holds the one-dimensional embedding (prolongation) matrix from mother element to all the children.

Definition at line 239 of file mg_transfer_matrix_free.h.

◆ evaluation_data

template<int dim, typename Number >

AlignedVector<VectorizedArray<Number> > MGTransferMatrixFree< dim, Number >::evaluation_data

mutableprivate

This variable holds the temporary values for the tensor evaluation

Definition at line 244 of file mg_transfer_matrix_free.h.

◆ weights_on_refined

template<int dim, typename Number >

std::vector<AlignedVector<VectorizedArray<Number> > > MGTransferMatrixFree< dim, Number >::weights_on_refined

private

For continuous elements, restriction is not additive and we need to weight the result at the end of prolongation (and at the start of restriction) by the valence of the degrees of freedom, i.e., on how many elements they appear. We store the data in vectorized form to allow for cheap access. Moreover, we utilize the fact that we only need to store 3^dim indices.

Data is organized in terms of each level (outer vector) and the cells on each level (inner vector).

Definition at line 257 of file mg_transfer_matrix_free.h.

◆ dirichlet_indices

template<int dim, typename Number >

std::vector<std::vector<std::vector<unsigned short> > > MGTransferMatrixFree< dim, Number >::dirichlet_indices

private

A variable storing the local indices of Dirichlet boundary conditions on cells for all levels (outer index), the cells within the levels (second index), and the indices on the cell (inner index).

Definition at line 264 of file mg_transfer_matrix_free.h.

◆ vector_partitioners

template<int dim, typename Number >

MGLevelObject<std::shared_ptr<const Utilities::MPI::Partitioner> > MGTransferMatrixFree< dim, Number >::vector_partitioners

private

A vector that holds shared pointers to the partitioners of the transfer. These partitioners might be shared with what was passed in from the outside through build() or be shared with the level vectors inherited from MGLevelGlobalTransfer.

Definition at line 273 of file mg_transfer_matrix_free.h.

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

include/deal.II/multigrid/mg_transfer_matrix_free.h
source/multigrid/mg_transfer_matrix_free.cc

Public Member Functions

Static Public Member Functions

Private Member Functions

Private Attributes

Additional Inherited Members

Detailed Description

template<int dim, typename Number> class MGTransferMatrixFree< dim, Number >

Constructor & Destructor Documentation

◆ MGTransferMatrixFree() [1/2]

◆ MGTransferMatrixFree() [2/2]

◆ ~MGTransferMatrixFree()

Member Function Documentation

◆ initialize_constraints()

◆ clear()

◆ build()

◆ prolongate()

◆ restrict_and_add()

◆ interpolate_to_mg()

◆ memory_consumption()

◆ do_prolongate_add()

◆ do_restrict_add()

Member Data Documentation

◆ fe_degree

◆ element_is_continuous

◆ n_components

◆ n_child_cell_dofs

◆ level_dof_indices

◆ parent_child_connect

◆ n_owned_level_cells

◆ prolongation_matrix_1d

◆ evaluation_data

◆ weights_on_refined

◆ dirichlet_indices

◆ vector_partitioners

template<int dim, typename Number>
class MGTransferMatrixFree< dim, Number >