Non-owning matrix view over external block storage and pattern. More...

#include <dune/istl/experimental/matrixview.hh>

Inheritance diagram for Dune::Experimental::MatrixView< B, P >:

Classes
class	block_const_iter_type
	Const block iterator adapter. More...

class	ConstIterator
	Const random-access iterator over matrix rows. More...

class	Iterator
	Mutable random-access iterator over matrix rows. More...

Public Types
using	block_iter_type = B
	The iterator type used to access the blocks of the matrix.

using	pattern_type = P
	The type used for the sparsity pattern.

using	row_index_range_type = std::ranges::range_value_t< pattern_type >
	The type used for the index set of rows.

using	block_type = std::iter_value_t< block_iter_type >
	The type of blocks in the matrix.

using	value_type = block_type
	The type of blocks in the matrix.

using	size_type = std::ranges::range_size_t< pattern_type >
	The type used to count elements in the row and column index sets.

using	field_type = typename FieldTraits< block_type >::field_type
	The type of the field.

using	row_type = VectorView< block_iter_type, row_index_range_type >
	The type representing a mutable matrix row.

using	const_row_type = VectorView< block_const_iter_type, row_index_range_type >
	The type representing a const matrix row.

using	iterator = Iterator
	The type of mutable matrix iterators over the rows.

using	const_iterator = ConstIterator
	The type of const matrix iterators over the rows.

using	RowIterator = Iterator
	The type of mutable matrix iterators over the rows.

using	ConstRowIterator = ConstIterator
	The type of const matrix iterators over the rows.

using	ColIterator = typename row_type::iterator
	The type of mutable row iterators over the column blocks.

using	ConstColIterator = typename const_row_type::const_iterator
	The type of const row iterators over the column blocks.

Public Member Functions
	MatrixView (block_iter_type block_iter, pattern_type const *pattern_ptr) noexcept
	Construct a view from data iterator and sparsity pattern.

row_type	operator[] (size_type i)
	Return a mutable view of row `i`.

const_row_type	operator[] (size_type i) const
	Return a const view of row `i`.

Iterator	begin ()
	Return iterator to the first row.

Iterator	end ()
	Return iterator one past the last row.

ConstIterator	begin () const
	Return const iterator to the first row.

ConstIterator	end () const
	Return const iterator one past the last row.

ConstIterator	cbegin () const
	Return const iterator to the first row.

ConstIterator	cend () const
	Return const iterator one past the last row.

template<class OtherB , class OtherI >
MatrixView &	axpy (field_type alpha, const MatrixView< OtherB, OtherI > &b)
	Compute \(this \leftarrow this + \alpha b\).

template<class X , class Y >
void	mv (const X &x, Y &y) const
	Compute \(y = Ax\).

template<class X , class Y >
void	umv (const X &x, Y &y) const
	Compute \(y \mathrel{+}= Ax\).

template<class X , class Y >
void	mmv (const X &x, Y &y) const
	Compute \(y \mathrel{-}= Ax\).

template<class X , class Y >
void	usmv (const field_type &alpha, const X &x, Y &y) const
	Compute \(y \mathrel{+}= \alpha Ax\).

template<class X , class Y >
void	mtv (const X &x, Y &y) const
	Compute \(y = A^T x\).

template<class X , class Y >
void	umtv (const X &x, Y &y) const
	Compute \(y \mathrel{+}= A^T x\).

template<class X , class Y >
void	mmtv (const X &x, Y &y) const
	Compute \(y \mathrel{-}= A^T x\).

template<class X , class Y >
void	usmtv (const field_type &alpha, const X &x, Y &y) const
	Compute \(y \mathrel{+}= \alpha A^T x\).

template<class X , class Y >
void	umhv (const X &x, Y &y) const
	Compute \(y \mathrel{+}= A^H x\) (Hermitian transpose).

template<class X , class Y >
void	mmhv (const X &x, Y &y) const
	Compute \(y \mathrel{-}= A^H x\) (Hermitian transpose).

template<class X , class Y >
void	usmhv (const field_type &alpha, const X &x, Y &y) const
	Compute \(y \mathrel{+}= \alpha A^H x\) (Hermitian transpose).

FieldTraits< field_type >::real_type	frobenius_norm2 () const
	Return \(\\|A\\|_F^2\) (sum of squared block Frobenius norms).

FieldTraits< field_type >::real_type	frobenius_norm () const
	Return the Frobenius norm \(\\|A\\|_F\).

FieldTraits< field_type >::real_type	infinity_norm () const
	Return the block-aware infinity norm.

FieldTraits< field_type >::real_type	infinity_norm_real () const
	Return simplified infinity norm (Manhattan norm for complex values).

bool	exists (size_type i, size_type j) const DUNE_ISTL_WITH_CHECKING_NOEXCEPT
	Test whether position \((i,j)\) is present in the sparsity pattern.

size_type	N () const
	Number of block rows.

size_type	M () const
	Number of block columns.

size_type	nonzeroes () const
	Number of stored block entries.

MatrixView &	operator*= (const field_type &k)
	Scale all stored blocks by `k`.

MatrixView &	operator/= (const field_type &k)
	Divide all stored blocks by `k`.

template<class OtherB , class OtherI >
MatrixView &	operator+= (const MatrixView< OtherB, OtherI > &b)
	Add another matrix view to this one.

template<class OtherB , class OtherI >
MatrixView &	operator-= (const MatrixView< OtherB, OtherI > &b)
	Subtract another matrix view from this one.

MatrixView &	operator= (const field_type &k)
	Assign all stored blocks to scalar `k`.

const pattern_type &	pattern () const

template<class OtherB , class OtherI >
MatrixView< B, I > &	operator+= (const MatrixView< OtherB, OtherI > &b)

template<class OtherB , class OtherI >
MatrixView< B, I > &	operator-= (const MatrixView< OtherB, OtherI > &b)

template<class OtherB , class OtherI >
MatrixView< B, I > &	axpy (field_type alpha, const MatrixView< OtherB, OtherI > &b)

Protected Member Functions
void	resetView (block_iter_type block_iter, pattern_type const *pattern_ptr)
	Reset the view to point to `block_iter` and `pattern_ptr`.

block_iter_type	blockIter ()
	Return the underlying block iterator.

block_const_iter_type	blockIter () const
	Return the underlying block iterator as a const iterator.

pattern_type const *	patternPtr () const
	Return the underlying pattern pointer.

Detailed Description

template<std::random_access_iterator B, class P>
class Dune::Experimental::MatrixView< B, P >

Non-owning matrix view over external block storage and pattern.

MatrixView binds two external objects:

a random-access iterator to block values,
a pattern that defines row offsets and column indices.

The block iterator is expected to point to at least pattern().count() blocks, which are interpreted in row-major order consistent with index ranges of pattern_type. That is, entries of row \(i\) start at an offset given by pattern().offset(i) and follow the column indices in pattern()[i].

The view does not own memory. The caller must ensure that both the data range and the pattern outlive the view. The pattern is treated as read-only for the lifetime of the view.

A pattern is a sized range of BorrowedOrderedIndexRange with three extra methods:

offset(i) counts the total number of entries in rows \(0\) to \(i-1\).
count() counts the total number of entries in the matrix.
range() returns the logical range of row indices.

Template Parameters

B	Random-access iterator type for matrix blocks.
P	Pattern type with row ranges and offsets.

Member Typedef Documentation

◆ block_iter_type

template<std::random_access_iterator B, class P >

using Dune::Experimental::MatrixView< B, P >::block_iter_type = B

The iterator type used to access the blocks of the matrix.

◆ block_type

template<std::random_access_iterator B, class P >

using Dune::Experimental::MatrixView< B, P >::block_type = std::iter_value_t<block_iter_type>

The type of blocks in the matrix.

◆ ColIterator

template<std::random_access_iterator B, class P >

using Dune::Experimental::MatrixView< B, P >::ColIterator = typename row_type::iterator

The type of mutable row iterators over the column blocks.

◆ const_iterator

template<std::random_access_iterator B, class P >

using Dune::Experimental::MatrixView< B, P >::const_iterator = ConstIterator

The type of const matrix iterators over the rows.

◆ const_row_type

template<std::random_access_iterator B, class P >

using Dune::Experimental::MatrixView< B, P >::const_row_type = VectorView<block_const_iter_type, row_index_range_type>

The type representing a const matrix row.

◆ ConstColIterator

template<std::random_access_iterator B, class P >

using Dune::Experimental::MatrixView< B, P >::ConstColIterator = typename const_row_type::const_iterator

The type of const row iterators over the column blocks.

◆ ConstRowIterator

template<std::random_access_iterator B, class P >

using Dune::Experimental::MatrixView< B, P >::ConstRowIterator = ConstIterator

The type of const matrix iterators over the rows.

◆ field_type

template<std::random_access_iterator B, class P >

using Dune::Experimental::MatrixView< B, P >::field_type = typename FieldTraits<block_type>::field_type

The type of the field.

◆ iterator

template<std::random_access_iterator B, class P >

using Dune::Experimental::MatrixView< B, P >::iterator = Iterator

The type of mutable matrix iterators over the rows.

◆ pattern_type

template<std::random_access_iterator B, class P >

using Dune::Experimental::MatrixView< B, P >::pattern_type = P

The type used for the sparsity pattern.

◆ row_index_range_type

template<std::random_access_iterator B, class P >

using Dune::Experimental::MatrixView< B, P >::row_index_range_type = std::ranges::range_value_t<pattern_type>

The type used for the index set of rows.

◆ row_type

template<std::random_access_iterator B, class P >

using Dune::Experimental::MatrixView< B, P >::row_type = VectorView<block_iter_type, row_index_range_type>

The type representing a mutable matrix row.

◆ RowIterator

template<std::random_access_iterator B, class P >

using Dune::Experimental::MatrixView< B, P >::RowIterator = Iterator

The type of mutable matrix iterators over the rows.

◆ size_type

template<std::random_access_iterator B, class P >

using Dune::Experimental::MatrixView< B, P >::size_type = std::ranges::range_size_t<pattern_type>

The type used to count elements in the row and column index sets.

◆ value_type

template<std::random_access_iterator B, class P >

using Dune::Experimental::MatrixView< B, P >::value_type = block_type

The type of blocks in the matrix.

Constructor & Destructor Documentation

◆ MatrixView()

template<std::random_access_iterator B, class P >

Dune::Experimental::MatrixView< B, P >::MatrixView	(	block_iter_type	block_iter,
		pattern_type const *	pattern_ptr
	)

inlinenoexcept

Construct a view from data iterator and sparsity pattern.

Parameters

data	Iterator to the first stored block.
pattern_ptr	Pointer to the external sparsity pattern.

Member Function Documentation

◆ axpy() [1/2]

template<std::random_access_iterator B, class P >

template<class OtherB , class OtherI >

MatrixView & Dune::Experimental::MatrixView< B, P >::axpy	(	field_type	alpha,
		const MatrixView< OtherB, OtherI > &	b
	)

Compute \(this \leftarrow this + \alpha b\).

◆ axpy() [2/2]

template<std::random_access_iterator B, class P >

template<class OtherB , class OtherI >

MatrixView< B, I > & Dune::Experimental::MatrixView< B, P >::axpy	(	field_type	alpha,
		const MatrixView< OtherB, OtherI > &	b
	)

◆ begin() [1/2]

template<std::random_access_iterator B, class P >

Iterator Dune::Experimental::MatrixView< B, P >::begin ( )

inline

Return iterator to the first row.

◆ begin() [2/2]

template<std::random_access_iterator B, class P >

ConstIterator Dune::Experimental::MatrixView< B, P >::begin ( ) const

inline

Return const iterator to the first row.

◆ blockIter() [1/2]

template<std::random_access_iterator B, class P >

block_iter_type Dune::Experimental::MatrixView< B, P >::blockIter ( )

inlineprotected

Return the underlying block iterator.

◆ blockIter() [2/2]

template<std::random_access_iterator B, class P >

block_const_iter_type Dune::Experimental::MatrixView< B, P >::blockIter ( ) const

inlineprotected

Return the underlying block iterator as a const iterator.

◆ cbegin()

template<std::random_access_iterator B, class P >

ConstIterator Dune::Experimental::MatrixView< B, P >::cbegin ( ) const

inline

Return const iterator to the first row.

◆ cend()

template<std::random_access_iterator B, class P >

ConstIterator Dune::Experimental::MatrixView< B, P >::cend ( ) const

inline

Return const iterator one past the last row.

◆ end() [1/2]

template<std::random_access_iterator B, class P >

Iterator Dune::Experimental::MatrixView< B, P >::end ( )

inline

Return iterator one past the last row.

◆ end() [2/2]

template<std::random_access_iterator B, class P >

ConstIterator Dune::Experimental::MatrixView< B, P >::end ( ) const

inline

Return const iterator one past the last row.

◆ exists()

template<std::random_access_iterator B, class P >

bool Dune::Experimental::MatrixView< B, P >::exists	(	size_type	i,
		size_type	j
	)		const

inline

Test whether position \((i,j)\) is present in the sparsity pattern.

This checks structural existence only. It does not inspect value magnitude.

Exceptions

BCRSMatrixError if \(i\) or \(j\) is out of range if DUNE_ISTL_WITH_CHECKING is defined.

◆ frobenius_norm()

template<std::random_access_iterator B, class I >

auto Dune::Experimental::MatrixView< B, I >::frobenius_norm ( ) const

Return the Frobenius norm \(\|A\|_F\).

◆ frobenius_norm2()

template<std::random_access_iterator B, class I >

auto Dune::Experimental::MatrixView< B, I >::frobenius_norm2 ( ) const

Return \(\|A\|_F^2\) (sum of squared block Frobenius norms).

◆ infinity_norm()

template<std::random_access_iterator B, class I >

auto Dune::Experimental::MatrixView< B, I >::infinity_norm ( ) const

Return the block-aware infinity norm.

◆ infinity_norm_real()

template<std::random_access_iterator B, class I >

auto Dune::Experimental::MatrixView< B, I >::infinity_norm_real ( ) const

Return simplified infinity norm (Manhattan norm for complex values).

infinity norm (maximum of absolute values of entries)

◆ M()

template<std::random_access_iterator B, class P >

size_type Dune::Experimental::MatrixView< B, P >::M ( ) const

inline

Number of block columns.

◆ mmhv()

template<std::random_access_iterator B, class I >

template<class X , class Y >

void Dune::Experimental::MatrixView< B, I >::mmhv	(	const X &	x,
		Y &	y
	)		const

Compute \(y \mathrel{-}= A^H x\) (Hermitian transpose).

◆ mmtv()

template<std::random_access_iterator B, class I >

template<class X , class Y >

void Dune::Experimental::MatrixView< B, I >::mmtv	(	const X &	x,
		Y &	y
	)		const

Compute \(y \mathrel{-}= A^T x\).

◆ mmv()

template<std::random_access_iterator B, class I >

template<class X , class Y >

void Dune::Experimental::MatrixView< B, I >::mmv	(	const X &	x,
		Y &	y
	)		const

Compute \(y \mathrel{-}= Ax\).

◆ mtv()

template<std::random_access_iterator B, class I >

template<class X , class Y >

void Dune::Experimental::MatrixView< B, I >::mtv	(	const X &	x,
		Y &	y
	)		const

Compute \(y = A^T x\).

◆ mv()

template<std::random_access_iterator B, class I >

template<class X , class Y >

void Dune::Experimental::MatrixView< B, I >::mv	(	const X &	x,
		Y &	y
	)		const

Compute \(y = Ax\).

◆ N()

template<std::random_access_iterator B, class P >

size_type Dune::Experimental::MatrixView< B, P >::N ( ) const

inline

Number of block rows.

◆ nonzeroes()

template<std::random_access_iterator B, class P >

size_type Dune::Experimental::MatrixView< B, P >::nonzeroes ( ) const

inline

Number of stored block entries.

This is the number of structurally present entries, i.e., entries that may be nonzero.

◆ operator*=()

template<std::random_access_iterator B, class I >

MatrixView< B, I > & Dune::Experimental::MatrixView< B, I >::operator*= ( const field_type & k )

Scale all stored blocks by k.

◆ operator+=() [1/2]

template<std::random_access_iterator B, class P >

template<class OtherB , class OtherI >

MatrixView & Dune::Experimental::MatrixView< B, P >::operator+= ( const MatrixView< OtherB, OtherI > & b )

Add another matrix view to this one.

Parameters

b	The matrix to add to this one. Its sparsity pattern has to be subset of the sparsity pattern of this matrix.

◆ operator+=() [2/2]

template<std::random_access_iterator B, class P >

template<class OtherB , class OtherI >

MatrixView< B, I > & Dune::Experimental::MatrixView< B, P >::operator+= ( const MatrixView< OtherB, OtherI > & b )

◆ operator-=() [1/2]

template<std::random_access_iterator B, class P >

template<class OtherB , class OtherI >

MatrixView & Dune::Experimental::MatrixView< B, P >::operator-= ( const MatrixView< OtherB, OtherI > & b )

Subtract another matrix view from this one.

Parameters

b	The matrix to subtract from this one. Its sparsity pattern has to be subset of the sparsity pattern of this matrix.

◆ operator-=() [2/2]

template<std::random_access_iterator B, class P >

template<class OtherB , class OtherI >

MatrixView< B, I > & Dune::Experimental::MatrixView< B, P >::operator-= ( const MatrixView< OtherB, OtherI > & b )

◆ operator/=()

template<std::random_access_iterator B, class I >

MatrixView< B, I > & Dune::Experimental::MatrixView< B, I >::operator/= ( const field_type & k )

Divide all stored blocks by k.

◆ operator=()

template<std::random_access_iterator B, class I >

MatrixView< B, I > & Dune::Experimental::MatrixView< B, I >::operator= ( const field_type & k )

Assign all stored blocks to scalar k.

◆ operator[]() [1/2]

template<std::random_access_iterator B, class P >

row_type Dune::Experimental::MatrixView< B, P >::operator[] ( size_type i )

inline

Return a mutable view of row i.

◆ operator[]() [2/2]

template<std::random_access_iterator B, class P >

const_row_type Dune::Experimental::MatrixView< B, P >::operator[] ( size_type i ) const

inline

Return a const view of row i.

◆ pattern()

template<std::random_access_iterator B, class P >

const pattern_type & Dune::Experimental::MatrixView< B, P >::pattern ( ) const

inline

◆ patternPtr()

template<std::random_access_iterator B, class P >

pattern_type const * Dune::Experimental::MatrixView< B, P >::patternPtr ( ) const

inlineprotected

Return the underlying pattern pointer.

◆ resetView()

template<std::random_access_iterator B, class P >

void Dune::Experimental::MatrixView< B, P >::resetView	(	block_iter_type	block_iter,
		pattern_type const *	pattern_ptr
	)

inlineprotected

Reset the view to point to block_iter and pattern_ptr.

◆ umhv()

template<std::random_access_iterator B, class I >

template<class X , class Y >

void Dune::Experimental::MatrixView< B, I >::umhv	(	const X &	x,
		Y &	y
	)		const

Compute \(y \mathrel{+}= A^H x\) (Hermitian transpose).

◆ umtv()

template<std::random_access_iterator B, class I >

template<class X , class Y >

void Dune::Experimental::MatrixView< B, I >::umtv	(	const X &	x,
		Y &	y
	)		const

Compute \(y \mathrel{+}= A^T x\).

◆ umv()

template<std::random_access_iterator B, class I >

template<class X , class Y >

void Dune::Experimental::MatrixView< B, I >::umv	(	const X &	x,
		Y &	y
	)		const

Compute \(y \mathrel{+}= Ax\).

◆ usmhv()

template<std::random_access_iterator B, class I >

template<class X , class Y >

void Dune::Experimental::MatrixView< B, I >::usmhv	(	const field_type &	alpha,
		const X &	x,
		Y &	y
	)		const

Compute \(y \mathrel{+}= \alpha A^H x\) (Hermitian transpose).

◆ usmtv()

template<std::random_access_iterator B, class I >

template<class X , class Y >

void Dune::Experimental::MatrixView< B, I >::usmtv	(	const field_type &	alpha,
		const X &	x,
		Y &	y
	)		const

Compute \(y \mathrel{+}= \alpha A^T x\).

◆ usmv()

template<std::random_access_iterator B, class I >

template<class X , class Y >

void Dune::Experimental::MatrixView< B, I >::usmv	(	const field_type &	alpha,
		const X &	x,
		Y &	y
	)		const

Compute \(y \mathrel{+}= \alpha Ax\).

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

matrixview.hh

Classes

Public Types

Public Member Functions

Protected Member Functions

Detailed Description

Member Typedef Documentation

◆ block_iter_type

◆ block_type

◆ ColIterator

◆ const_iterator

◆ const_row_type

◆ ConstColIterator

◆ ConstRowIterator

◆ field_type

◆ iterator

◆ pattern_type

◆ row_index_range_type

◆ row_type

◆ RowIterator

◆ size_type

◆ value_type

Constructor & Destructor Documentation

◆ MatrixView()

Member Function Documentation

◆ axpy() [1/2]

◆ axpy() [2/2]

◆ begin() [1/2]

◆ begin() [2/2]

◆ blockIter() [1/2]

◆ blockIter() [2/2]

◆ cbegin()

◆ cend()

◆ end() [1/2]

◆ end() [2/2]

◆ exists()

◆ frobenius_norm()

◆ frobenius_norm2()

◆ infinity_norm()

◆ infinity_norm_real()

◆ M()

◆ mmhv()

◆ mmtv()

◆ mmv()

◆ mtv()

◆ mv()

◆ N()

◆ nonzeroes()

◆ operator*=()

◆ operator+=() [1/2]

◆ operator+=() [2/2]

◆ operator-=() [1/2]

◆ operator-=() [2/2]

◆ operator/=()

◆ operator=()

◆ operator[]() [1/2]

◆ operator[]() [2/2]

◆ pattern()

◆ patternPtr()

◆ resetView()

◆ umhv()

◆ umtv()

◆ umv()

◆ usmhv()

◆ usmtv()

◆ usmv()