PETScWrappers::MatrixIterators::const_iterator::Accessor Class Reference

Detailed Description

Accessor class for iterators

Definition at line 83 of file petsc_matrix_base.h.

Public Types
using	size_type = types::global_dof_index

Public Member Functions
	Accessor (const MatrixBase *matrix, const size_type row, const size_type index)
size_type	row () const
size_type	index () const
size_type	column () const
PetscScalar	value () const

Static Public Member Functions
static ::ExceptionBase &	ExcBeyondEndOfMatrix ()
static ::ExceptionBase &	ExcAccessToNonlocalRow (int arg1, int arg2, int arg3)

Private Member Functions
void	visit_present_row ()

Private Attributes
MatrixBase *	matrix
size_type	a_row
size_type	a_index
std::shared_ptr< const std::vector< size_type > >	colnum_cache
std::shared_ptr< const std::vector< PetscScalar > >	value_cache

Friends
class	const_iterator

Member Typedef Documentation

size_type

using PETScWrappers::MatrixIterators::const_iterator::Accessor::size_type = types::global_dof_index

Declare type for container size.

Definition at line 89 of file petsc_matrix_base.h.

Constructor & Destructor Documentation

Accessor()

PETScWrappers::MatrixIterators::const_iterator::Accessor::Accessor	(	const MatrixBase *	matrix,
		const size_type	row,
		const size_type	index )

Constructor. Since we use accessors only for read access, a const matrix pointer is sufficient.

Member Function Documentation

row()

size_type PETScWrappers::MatrixIterators::const_iterator::Accessor::row

(

)

const

Row number of the element represented by this object.

index()

size_type PETScWrappers::MatrixIterators::const_iterator::Accessor::index

(

)

const

Index in row of the element represented by this object.

column()

size_type PETScWrappers::MatrixIterators::const_iterator::Accessor::column

(

)

const

Column number of the element represented by this object.

value()

PetscScalar PETScWrappers::MatrixIterators::const_iterator::Accessor::value

(

)

const

Value of this matrix entry.

visit_present_row()

void PETScWrappers::MatrixIterators::const_iterator::Accessor::visit_present_row ( )

private

Discard the old row caches (they may still be used by other accessors) and generate new ones for the row pointed to presently by this accessor.

Friends And Related Symbol Documentation

const_iterator

friend class const_iterator

friend

Definition at line 183 of file petsc_matrix_base.h.

Member Data Documentation

matrix

MatrixBase* PETScWrappers::MatrixIterators::const_iterator::Accessor::matrix

mutableprivate

The matrix accessed.

Definition at line 143 of file petsc_matrix_base.h.

a_row

size_type PETScWrappers::MatrixIterators::const_iterator::Accessor::a_row

private

Current row number.

Definition at line 148 of file petsc_matrix_base.h.

a_index

size_type PETScWrappers::MatrixIterators::const_iterator::Accessor::a_index

private

Current index in row.

Definition at line 153 of file petsc_matrix_base.h.

colnum_cache

std::shared_ptr<const std::vector<size_type> > PETScWrappers::MatrixIterators::const_iterator::Accessor::colnum_cache

private

Cache where we store the column indices of the present row. This is necessary, since PETSc makes access to the elements of its matrices rather hard, and it is much more efficient to copy all column entries of a row once when we enter it than repeatedly asking PETSc for individual ones. This also makes some sense since it is likely that we will access them sequentially anyway.

In order to make copying of iterators/accessor of acceptable performance, we keep a shared pointer to these entries so that more than one accessor can access this data if necessary.

Definition at line 167 of file petsc_matrix_base.h.

value_cache

std::shared_ptr<const std::vector<PetscScalar> > PETScWrappers::MatrixIterators::const_iterator::Accessor::value_cache

private

Similar cache for the values of this row.

Definition at line 172 of file petsc_matrix_base.h.

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

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