Reference documentation for deal.II version Git 497f915867 2021-09-17 22:46:48 +0200
SparseMatrixIterators::Accessor< number, true > Class Template Reference

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

Inheritance diagram for SparseMatrixIterators::Accessor< number, true >:
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## Public Types

using MatrixType = const SparseMatrix< number >

using size_type = SparsityPatternIterators::size_type

## Public Member Functions

Accessor (MatrixType *matrix, const std::size_t index_within_matrix)

Accessor (MatrixType *matrix)

Accessor (const SparseMatrixIterators::Accessor< number, false > &a)

number value () const

const MatrixTypeget_matrix () const

size_type row () const

size_type index () const

size_type global_index () const

size_type column () const

bool is_valid_entry () const

bool operator== (const Accessor &) const

bool operator< (const Accessor &) const

## Static Protected Member Functions

static ::ExceptionBaseDummyAccessor ()

## Protected Attributes

const SparsityPatternBasecontainer

std::size_t linear_index

MatrixTypematrix

## Friends

template<typename , bool >
class Iterator

## Detailed Description

### template<typename number> class SparseMatrixIterators::Accessor< number, true >

Accessor class for constant matrices, used in the const_iterators. This class builds on the accessor classes used for sparsity patterns to loop over all nonzero entries, and only adds the accessor functions to gain access to the actual value stored at a certain location.

Definition at line 132 of file sparse_matrix.h.

## ◆ MatrixType

template<typename number >
 using SparseMatrixIterators::Accessor< number, true >::MatrixType = const SparseMatrix

Typedef for the type (including constness) of the matrix to be used here.

Definition at line 139 of file sparse_matrix.h.

## ◆ size_type

 inherited

Size type of SparsityPattern.

Definition at line 137 of file sparsity_pattern.h.

## ◆ Accessor() [1/3]

template<typename number >
 SparseMatrixIterators::Accessor< number, true >::Accessor ( MatrixType * matrix, const std::size_t index_within_matrix )

Constructor.

## ◆ Accessor() [2/3]

template<typename number >
 SparseMatrixIterators::Accessor< number, true >::Accessor ( MatrixType * matrix )

Constructor. Construct the end accessor for the given matrix.

## ◆ Accessor() [3/3]

template<typename number >
 SparseMatrixIterators::Accessor< number, true >::Accessor ( const SparseMatrixIterators::Accessor< number, false > & a )

Copy constructor to get from a non-const accessor to a const accessor.

## ◆ value()

template<typename number >
 number SparseMatrixIterators::Accessor< number, true >::value ( ) const

Value of this matrix entry.

## ◆ get_matrix()

template<typename number >
 const MatrixType& SparseMatrixIterators::Accessor< number, true >::get_matrix ( ) const

Return a reference to the matrix into which this accessor points. Note that in the present case, this is a constant reference.

## ◆ row()

 size_type SparsityPatternIterators::Accessor::row ( ) const
inherited

Row number of the element represented by this object. This function can only be called for entries for which is_valid_entry() is true.

## ◆ index()

 size_type SparsityPatternIterators::Accessor::index ( ) const
inherited

Index within the current row of the element represented by this object. This function can only be called for entries for which is_valid_entry() is true.

## ◆ global_index()

 size_type SparsityPatternIterators::Accessor::global_index ( ) const
inherited

This function returns the how-many'th entry within the entire sparsity pattern the current iterator points to. While the order of entries in a sparsity pattern is generally not important, this function allows indexing entries of the sparsity pattern using a linear index.

This function can only be called for entries for which is_valid_entry() is true.

## ◆ column()

 size_type SparsityPatternIterators::Accessor::column ( ) const
inherited

Column number of the element represented by this object. This function can only be called for entries for which is_valid_entry() is true.

## ◆ is_valid_entry()

 bool SparsityPatternIterators::Accessor::is_valid_entry ( ) const
inherited

Return whether the sparsity pattern entry pointed to by this iterator is valid or not. Note that after compressing the sparsity pattern, all entries are valid. However, before compression, the sparsity pattern allocated some memory to be used while still adding new nonzero entries; if you create iterators in this phase of the sparsity pattern's lifetime, you will iterate over elements that are not valid. If this is so, then this function will return false.

## ◆ operator==()

 bool SparsityPatternIterators::Accessor::operator== ( const Accessor & ) const
inherited

Comparison. True, if both iterators point to the same matrix position.

## ◆ operator<()

 bool SparsityPatternIterators::Accessor::operator< ( const Accessor & ) const
inherited

Comparison operator. Result is true if either the first row number is smaller or if the row numbers are equal and the first index is smaller.

This function is only valid if both iterators point into the same sparsity pattern.

protectedinherited

Move the accessor to the next nonzero entry in the matrix.

## ◆ Iterator

template<typename number >
template<typename , bool >
 friend class Iterator
friend

Definition at line 182 of file sparse_matrix.h.

## ◆ matrix

template<typename number >
 MatrixType* SparseMatrixIterators::Accessor< number, true >::matrix
private

Pointer to the matrix we use.

Definition at line 173 of file sparse_matrix.h.

## ◆ container

 const SparsityPatternBase* SparsityPatternIterators::Accessor::container
protectedinherited

The sparsity pattern we operate on accessed.

Definition at line 228 of file sparsity_pattern.h.

## ◆ linear_index

 std::size_t SparsityPatternIterators::Accessor::linear_index
protectedinherited

Index in global sparsity pattern. This index represents the location the iterator/accessor points to within the array of the SparsityPattern class that stores the column numbers. It is also the index within the values array of a sparse matrix that stores the corresponding value of this site.

Definition at line 237 of file sparsity_pattern.h.

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