SparsityPattern Class Reference

Sparsity pattern data structure that can be used to initialize sparse matrices. After assembly, column indices are always sorted in increasing order. Ghost entries are kept after assembly. More...

#include <SparsityPattern.h>

Public Member Functions
	SparsityPattern (MPI_Comm comm, const std::array< std::shared_ptr< const common::IndexMap >, 2 > &maps, const std::array< int, 2 > &bs)
	Create an empty sparsity pattern with specified dimensions.
	SparsityPattern (MPI_Comm comm, const std::vector< std::vector< const SparsityPattern * > > &patterns, const std::array< std::vector< std::pair< std::reference_wrapper< const common::IndexMap >, int > >, 2 > &maps, const std::array< std::vector< int >, 2 > &bs)
	Create a new sparsity pattern by concatenating sub-patterns, e.g. pattern =[ pattern00 ][ pattern 01] [ pattern10 ][ pattern 11].
	SparsityPattern (const SparsityPattern &pattern)=delete
	SparsityPattern (SparsityPattern &&pattern)=default
	Move constructor.
	~SparsityPattern ()=default
	Destructor.
SparsityPattern &	operator= (SparsityPattern &&pattern)=default
	Move assignment.
void	insert (const std::span< const std::int32_t > &rows, const std::span< const std::int32_t > &cols)
	Insert non-zero locations using local (process-wise) indices.
void	insert_diagonal (std::span< const std::int32_t > rows)
	Insert non-zero locations on the diagonal.
void	finalize ()
	Finalize sparsity pattern and communicate off-process entries.
std::shared_ptr< const common::IndexMap >	index_map (int dim) const
	Index map for given dimension dimension. Returns the index map for rows and columns that will be set by the current MPI rank.
std::vector< std::int64_t >	column_indices () const
	Global indices of non-zero columns on owned rows.
common::IndexMap	column_index_map () const
	Builds the index map for columns after assembly of the sparsity pattern.
int	block_size (int dim) const
	Return index map block size for dimension dim.
std::int64_t	num_nonzeros () const
	Number of nonzeros on this rank after assembly, including ghost rows.
std::int32_t	nnz_diag (std::int32_t row) const
	Number of non-zeros in owned columns (diagonal block) on a given row.
std::int32_t	nnz_off_diag (std::int32_t row) const
	Number of non-zeros in unowned columns (off-diagonal block) on a given row.
std::pair< std::span< const std::int32_t >, std::span< const std::int64_t > >	graph () const
	Sparsity pattern graph after assembly. Uses local indices for the columns.
std::span< const std::int32_t >	off_diagonal_offsets () const
	Row-wise start of off-diagonals (unowned columns) for each row.
MPI_Comm	comm () const
	Return MPI communicator.

Detailed Description

Sparsity pattern data structure that can be used to initialize sparse matrices. After assembly, column indices are always sorted in increasing order. Ghost entries are kept after assembly.

Constructor & Destructor Documentation

SparsityPattern() [1/2]

SparsityPattern	(	MPI_Comm	comm,
		const std::array< std::shared_ptr< const common::IndexMap >, 2 > &	maps,
		const std::array< int, 2 > &	bs
	)

Create an empty sparsity pattern with specified dimensions.

Parameters

[in]	comm	Communicator that the pattern is defined on.
[in]	maps	Index maps describing the [0] row and [1] column index ranges (up to a block size).
[in]	bs	Block sizes for the [0] row and [1] column maps.

SparsityPattern() [2/2]

SparsityPattern	(	MPI_Comm	comm,
		const std::vector< std::vector< const SparsityPattern * > > &	patterns,
		const std::array< std::vector< std::pair< std::reference_wrapper< const common::IndexMap >, int > >, 2 > &	maps,
		const std::array< std::vector< int >, 2 > &	bs
	)

Create a new sparsity pattern by concatenating sub-patterns, e.g. pattern =[ pattern00 ][ pattern 01] [ pattern10 ][ pattern 11].

Parameters

[in]	comm	Communicator that the pattern is defined on.
[in]	patterns	Rectangular array of sparsity pattern. The patterns must not be finalised. Null block are permitted/
[in]	maps	Pairs of (index map, block size) for each row block (maps[0]) and column blocks (maps[1])/
[in]	bs	Block sizes for the sparsity pattern entries/

Member Function Documentation

column_index_map()

common::IndexMap column_index_map

(

)

const

Builds the index map for columns after assembly of the sparsity pattern.

Returns

Map for all non-zero columns on this process, including ghosts

Todo:

Should this be compted and stored when finalising the SparsityPattern?

column_indices()

std::vector< std::int64_t > column_indices

(

)

const

Global indices of non-zero columns on owned rows.

Note

The ghosts are computed only once SparsityPattern::finalize has been called.

Returns

Global index non-zero columns on this process, including ghosts.

graph()

std::pair< std::span< const std::int32_t >, std::span< const std::int64_t > > graph

(

)

const

Sparsity pattern graph after assembly. Uses local indices for the columns.

Note

Column global indices can be obtained from SparsityPattern::column_index_map()

Includes ghost rows

Returns

Adjacency list edges and offsets

index_map()

std::shared_ptr< const common::IndexMap > index_map

(

int

dim

)

const

Index map for given dimension dimension. Returns the index map for rows and columns that will be set by the current MPI rank.

Parameters

[in]

dim

Requested map, row (0) or column (1).

Returns

The index map.

insert_diagonal()

void insert_diagonal

(

std::span< const std::int32_t >

rows

)

Insert non-zero locations on the diagonal.

Parameters

[in]

rows

Rows in local (process-wise) indices. The indices must exist in the row IndexMap.

nnz_diag()

std::int32_t nnz_diag

(

std::int32_t

row

)

const

Number of non-zeros in owned columns (diagonal block) on a given row.

Note

Can also be used on ghost rows

nnz_off_diag()

std::int32_t nnz_off_diag

(

std::int32_t

row

)

const

Number of non-zeros in unowned columns (off-diagonal block) on a given row.

Note

Can also be used on ghost rows

off_diagonal_offsets()

std::span< const std::int32_t > off_diagonal_offsets

(

)

const

Row-wise start of off-diagonals (unowned columns) for each row.

Note

Includes ghost rows

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

• /__w/dolfinx/dolfinx/cpp/dolfinx/la/SparsityPattern.h
• /__w/dolfinx/dolfinx/cpp/dolfinx/la/SparsityPattern.cpp