DiagonalMatrix< VectorType > Class Template Reference

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

Inheritance diagram for DiagonalMatrix< VectorType >:

Public Types
using	value_type = typename VectorType::value_type
using	size_type = typename VectorType::size_type

Public Member Functions
	DiagonalMatrix ()=default
	DiagonalMatrix (const VectorType &vec)
void	reinit (const VectorType &vec)
void	compress (VectorOperation::values operation)
VectorType &	get_vector ()
void	clear ()
const VectorType &	get_vector () const
size_type	m () const
size_type	n () const
value_type	operator() (const size_type i, const size_type j) const
value_type &	operator() (const size_type i, const size_type j)
template<typename number2 >
void	add (const size_type row, const size_type n_cols, const size_type *col_indices, const number2 *values, const bool elide_zero_values=true, const bool col_indices_are_sorted=false)
void	add (const size_type i, const size_type j, const value_type value)
void	vmult (VectorType &dst, const VectorType &src) const
void	Tvmult (VectorType &dst, const VectorType &src) const
void	vmult_add (VectorType &dst, const VectorType &src) const
void	Tvmult_add (VectorType &dst, const VectorType &src) const
void	initialize_dof_vector (VectorType &dst) const
std::size_t	memory_consumption () 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 (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)

Private Attributes
VectorType	diagonal

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 VectorType = Vector<double>>
class DiagonalMatrix< VectorType >

This class represents a n x n diagonal matrix based on a vector of size n. The matrix-vector products are realized by VectorType::scale, so the template vector class needs to provide a scale() method.

When using this class with ConstraintsMatrix::distribute_local_to_global(), the underlying vector needs to provide write access to all entries referenced by cells in an assembly process. This means that this class also needs access to ghost entries that are owned by other processors than the calling one. In practice this requires initialization of the vector as follows

DiagonalMatrix<LinearAlgebra::distributed::Vector<double> > diagonal_matrix;
LinearAlgebra::distributed::Vector<double> &diagonal_vector =
  diagonal_matrix.get_vector();
diagonal_vector.reinit(locally_owned_dofs,
                       locally_relevant_dofs,
                       mpi_communicator);

Author

Martin Kronbichler, 2016

Definition at line 50 of file diagonal_matrix.h.

Member Typedef Documentation

value_type

template<typename VectorType = Vector<double>>

using DiagonalMatrix< VectorType >::value_type = typename VectorType::value_type

Definition at line 53 of file diagonal_matrix.h.

size_type

template<typename VectorType = Vector<double>>

using DiagonalMatrix< VectorType >::size_type = typename VectorType::size_type

Definition at line 54 of file diagonal_matrix.h.

Constructor & Destructor Documentation

DiagonalMatrix() [1/2]

template<typename VectorType = Vector<double>>

DiagonalMatrix< VectorType >::DiagonalMatrix ( )

default

Default constructor. The object needs still to be reinitialized to be usable.

DiagonalMatrix() [2/2]

template<typename VectorType = Vector<double>>

DiagonalMatrix< VectorType >::DiagonalMatrix ( const VectorType &  vec )

explicit

Constructor initializing this object as a diagonal matrix of size n x n where n is the size of the vector, and with diagonal entries equal to the elements of vec.

Member Function Documentation

reinit()

template<typename VectorType = Vector<double>>

void DiagonalMatrix< VectorType >::reinit

(

const VectorType &

vec

)

Initialize with a given vector by copying the content of the vector vec.

compress()

template<typename VectorType = Vector<double>>

void DiagonalMatrix< VectorType >::compress

(

VectorOperation::values

operation

)

Compresses the data structures and allows the resulting matrix to be used in all other operations like matrix-vector products. This is a collective operation, i.e., it needs to be run on all processors when used in parallel.

get_vector() [1/2]

template<typename VectorType = Vector<double>>

VectorType& DiagonalMatrix< VectorType >::get_vector

(

)

Return a reference to the underlying vector for manipulation of the entries on the matrix diagonal.

clear()

template<typename VectorType = Vector<double>>

void DiagonalMatrix< VectorType >::clear

(

)

Clear content of this object and reset to the state of default constructor.

get_vector() [2/2]

template<typename VectorType = Vector<double>>

const VectorType& DiagonalMatrix< VectorType >::get_vector

(

)

const

Return a read-only reference to the underlying vector.

m()

template<typename VectorType = Vector<double>>

size_type DiagonalMatrix< VectorType >::m

(

)

const

Number of rows of this matrix. This number corresponds to the size of the underlying vector.

n()

template<typename VectorType = Vector<double>>

size_type DiagonalMatrix< VectorType >::n

(

)

const

Number of columns of this matrix. This number corresponds to the size of the underlying vector.

operator()() [1/2]

template<typename VectorType = Vector<double>>

value_type DiagonalMatrix< VectorType >::operator()	(	const size_type	i,
		const size_type	j
	)		const

Read-only access to a value. This is restricted to the case where i==j due to the matrix storage.

If the vector representing the diagonal is distributed with MPI, not all of the indices i might actually be accessible. Refer to the method get_vector().locally_owned_elements() for the entries that actually are accessible.

operator()() [2/2]

template<typename VectorType = Vector<double>>

value_type& DiagonalMatrix< VectorType >::operator()	(	const size_type	i,
		const size_type	j
	)

Read-write access to a value. This is restricted to the case where i==j due to the matrix storage.

If the vector representing the diagonal is distributed with MPI, not all of the indices i might actually be accessible. Refer to the method get_vector().locally_owned_elements() for the entries that actually are accessible.

add() [1/2]

template<typename VectorType = Vector<double>>

template<typename number2 >

void DiagonalMatrix< VectorType >::add	(	const size_type	row,
		const size_type	n_cols,
		const size_type *	col_indices,
		const number2 *	values,
		const bool	elide_zero_values = true,
		const bool	col_indices_are_sorted = false
	)

Add an array of values given by values in the given global matrix row at columns specified by col_indices. Due to the storage of this matrix, entries are only added to the diagonal of the matrix. All other entries are ignored and no exception is thrown.

This function is for a consistent interface with the other matrix classes in deal.II and can be used in AffineConstraints::distribute_local_to_global to get exactly the same diagonal as when assembling into a sparse matrix.

add() [2/2]

template<typename VectorType = Vector<double>>

void DiagonalMatrix< VectorType >::add	(	const size_type	i,
		const size_type	j,
		const value_type	value
	)

Add value to the element (i,j).

Due to the storage of this matrix, entries are only added to the diagonal of the matrix. All other entries are ignored and no exception is thrown.

vmult()

template<typename VectorType = Vector<double>>

void DiagonalMatrix< VectorType >::vmult	(	VectorType &	dst,
		const VectorType &	src
	)		const

Performs a matrix-vector multiplication with the given matrix.

Tvmult()

template<typename VectorType = Vector<double>>

void DiagonalMatrix< VectorType >::Tvmult	(	VectorType &	dst,
		const VectorType &	src
	)		const

Performs a transpose matrix-vector multiplication with the given matrix. Since this represents a diagonal matrix, exactly the same as vmult().

vmult_add()

template<typename VectorType = Vector<double>>

void DiagonalMatrix< VectorType >::vmult_add	(	VectorType &	dst,
		const VectorType &	src
	)		const

Adds the result of a matrix-vector multiplication into the destination vector dst. Needs to create a temporary vector, which makes performance slower than for vmult().

Tvmult_add()

template<typename VectorType = Vector<double>>

void DiagonalMatrix< VectorType >::Tvmult_add	(	VectorType &	dst,
		const VectorType &	src
	)		const

Adds the result of a transpose matrix-vector multiplication into the destination vector dst. Needs to create a temporary vector, which makes performance slower than for Tvmult().

initialize_dof_vector()

template<typename VectorType = Vector<double>>

void DiagonalMatrix< VectorType >::initialize_dof_vector

(

VectorType &

dst

)

const

Initialize vector dst to have the same size and partition as diagonal member of this class.

This is a part of the interface required by linear_operator().

memory_consumption()

template<typename VectorType = Vector<double>>

std::size_t DiagonalMatrix< VectorType >::memory_consumption

(

)

const

Return the memory consumption of this object.

Member Data Documentation

diagonal

template<typename VectorType = Vector<double>>

VectorType DiagonalMatrix< VectorType >::diagonal

private

The stored vector.

Definition at line 221 of file diagonal_matrix.h.

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

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