BlockMatrixBase< MatrixType > Class Template Reference

#include <deal.II/lac/block_matrix_base.h>

Inheritance diagram for BlockMatrixBase< MatrixType >:

Classes
struct	TemporaryData

Public Types
using	BlockType = MatrixType
using	value_type = typename BlockType::value_type
using	real_type = typename numbers::NumberTraits< value_type >::real_type
using	pointer = value_type *
using	const_pointer = const value_type *
using	reference = value_type &
using	const_reference = const value_type &
using	size_type = types::global_dof_index
using	iterator = MatrixIterator< BlockMatrixIterators::Accessor< BlockMatrixBase, false > >
using	const_iterator = MatrixIterator< BlockMatrixIterators::Accessor< BlockMatrixBase, true > >

Public Member Functions
	BlockMatrixBase ()=default
	~BlockMatrixBase () override
template<class BlockMatrixType >
BlockMatrixBase &	copy_from (const BlockMatrixType &source)
BlockType &	block (const unsigned int row, const unsigned int column)
const BlockType &	block (const unsigned int row, const unsigned int column) const
size_type	m () const
size_type	n () const
unsigned int	n_block_rows () const
unsigned int	n_block_cols () const
void	set (const size_type i, const size_type j, const value_type value)
template<typename number >
void	set (const std::vector< size_type > &indices, const FullMatrix< number > &full_matrix, const bool elide_zero_values=false)
template<typename number >
void	set (const std::vector< size_type > &row_indices, const std::vector< size_type > &col_indices, const FullMatrix< number > &full_matrix, const bool elide_zero_values=false)
template<typename number >
void	set (const size_type row, const std::vector< size_type > &col_indices, const std::vector< number > &values, const bool elide_zero_values=false)
template<typename number >
void	set (const size_type row, const size_type n_cols, const size_type *col_indices, const number *values, const bool elide_zero_values=false)
void	add (const size_type i, const size_type j, const value_type value)
template<typename number >
void	add (const std::vector< size_type > &indices, const FullMatrix< number > &full_matrix, const bool elide_zero_values=true)
template<typename number >
void	add (const std::vector< size_type > &row_indices, const std::vector< size_type > &col_indices, const FullMatrix< number > &full_matrix, const bool elide_zero_values=true)
template<typename number >
void	add (const size_type row, const std::vector< size_type > &col_indices, const std::vector< number > &values, const bool elide_zero_values=true)
template<typename number >
void	add (const size_type row, const size_type n_cols, const size_type *col_indices, const number *values, const bool elide_zero_values=true, const bool col_indices_are_sorted=false)
void	add (const value_type factor, const BlockMatrixBase< MatrixType > &matrix)
value_type	operator() (const size_type i, const size_type j) const
value_type	el (const size_type i, const size_type j) const
value_type	diag_element (const size_type i) const
void	compress (::VectorOperation::values operation)
BlockMatrixBase &	operator*= (const value_type factor)
BlockMatrixBase &	operator/= (const value_type factor)
template<class BlockVectorType >
void	vmult_add (BlockVectorType &dst, const BlockVectorType &src) const
template<class BlockVectorType >
void	Tvmult_add (BlockVectorType &dst, const BlockVectorType &src) const
template<class BlockVectorType >
value_type	matrix_norm_square (const BlockVectorType &v) const
real_type	frobenius_norm () const
template<class BlockVectorType >
value_type	matrix_scalar_product (const BlockVectorType &u, const BlockVectorType &v) const
template<class BlockVectorType >
value_type	residual (BlockVectorType &dst, const BlockVectorType &x, const BlockVectorType &b) const
void	print (std::ostream &out, const bool alternative_output=false) const
iterator	begin ()
iterator	end ()
iterator	begin (const size_type r)
iterator	end (const size_type r)
const_iterator	begin () const
const_iterator	end () const
const_iterator	begin (const size_type r) const
const_iterator	end (const size_type r) const
const BlockIndices &	get_row_indices () const
const BlockIndices &	get_column_indices () const
std::size_t	memory_consumption () const

Static Public Member Functions
static ::ExceptionBase &	ExcIncompatibleRowNumbers (int arg1, int arg2, int arg3, int arg4)
static ::ExceptionBase &	ExcIncompatibleColNumbers (int arg1, int arg2, int arg3, int arg4)

Protected Member Functions
void	clear ()
void	collect_sizes ()
template<class BlockVectorType >
void	vmult_block_block (BlockVectorType &dst, const BlockVectorType &src) const
template<class BlockVectorType , class VectorType >
void	vmult_block_nonblock (BlockVectorType &dst, const VectorType &src) const
template<class BlockVectorType , class VectorType >
void	vmult_nonblock_block (VectorType &dst, const BlockVectorType &src) const
template<class VectorType >
void	vmult_nonblock_nonblock (VectorType &dst, const VectorType &src) const
template<class BlockVectorType >
void	Tvmult_block_block (BlockVectorType &dst, const BlockVectorType &src) const
template<class BlockVectorType , class VectorType >
void	Tvmult_block_nonblock (BlockVectorType &dst, const VectorType &src) const
template<class BlockVectorType , class VectorType >
void	Tvmult_nonblock_block (VectorType &dst, const BlockVectorType &src) const
template<class VectorType >
void	Tvmult_nonblock_nonblock (VectorType &dst, const VectorType &src) const
void	prepare_add_operation ()
void	prepare_set_operation ()

Protected Attributes
BlockIndices	row_block_indices
BlockIndices	column_block_indices
Table< 2, SmartPointer< BlockType, BlockMatrixBase< MatrixType > > >	sub_objects

Private Attributes
TemporaryData	temporary_data

Friends
template<typename , bool >
class	BlockMatrixIterators::Accessor
template<typename >
class	MatrixIterator

Subscriptor functionality
Classes derived from Subscriptor provide a facility to subscribe to this object. This is mostly used by the SmartPointer class.
std::atomic< unsigned int >	counter
std::map< std::string, unsigned int >	counter_map
std::vector< std::atomic< bool > * >	validity_pointers
const std::type_info *	object_info
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 ::ExceptionBase &	ExcInUse (int arg1, std::string arg2, std::string arg3)
static ::ExceptionBase &	ExcNoSubscriber (std::string arg1, std::string arg2)
using	map_value_type = decltype(counter_map)::value_type
using	map_iterator = decltype(counter_map)::iterator
static std::mutex	mutex
void	check_no_subscribers () const noexcept

Detailed Description

template<typename MatrixType>
class BlockMatrixBase< MatrixType >

Blocked matrix class. The behavior of objects of this type is almost as for the usual matrix objects, with most of the functions being implemented in both classes. The main difference is that the matrix represented by this object is composed of an array of matrices (e.g. of type SparseMatrix<number>) and all accesses to the elements of this object are relayed to accesses of the base matrices. The actual type of the individual blocks of this matrix is the type of the template argument, and can, for example be the usual SparseMatrix or PETScWrappers::SparseMatrix.

In addition to the usual matrix access and linear algebra functions, there are functions block() which allow access to the different blocks of the matrix. This may, for example, be of help when you want to implement Schur complement methods, or block preconditioners, where each block belongs to a specific component of the equation you are presently discretizing.

Note that the numbers of blocks and rows are implicitly determined by the sparsity pattern objects used.

Objects of this type are frequently used when a system of differential equations has solutions with variables that fall into different classes. For example, solutions of the Stokes or Navier-Stokes equations have dim velocity components and one pressure component. In this case, it may make sense to consider the linear system of equations as a system of 2x2 blocks, and one can construct preconditioners or solvers based on this 2x2 block structure. This class can help you in these cases, as it allows to view the matrix alternatively as one big matrix, or as a number of individual blocks.

Inheriting from this class

Since this class simply forwards its calls to the subobjects (if necessary after adjusting indices denoting which subobject is meant), this class is completely independent of the actual type of the subobject. The functions that set up block matrices and destroy them, however, have to be implemented in derived classes. These functions also have to fill the data members provided by this base class, as they are only used passively in this class.

Most of the functions take a vector or block vector argument. These functions can, in general, only successfully be compiled if the individual blocks of this matrix implement the respective functions operating on the vector type in question. For example, if you have a block sparse matrix over deal.II SparseMatrix objects, then you will likely not be able to form the matrix-vector multiplication with a block vector over PETScWrappers::SparseMatrix objects. If you attempt anyway, you will likely get a number of compiler errors.

Note

Instantiations for this template are provided for <float> and <double>; others can be generated in application programs (see the section on Template instantiations in the manual).

See also

Block (linear algebra)

Definition at line 349 of file block_matrix_base.h.

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

• include/deal.II/lac/block_matrix_base.h