Reference documentation for deal.II version Git 78a8940608 2021-04-17 09:24:19 -0400
SparsityPatternIterators::Accessor Class Reference

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

Inheritance diagram for SparsityPatternIterators::Accessor:
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## Public Types

using size_type = SparsityPatternIterators::size_type

## Public Member Functions

Accessor (const SparsityPatternBase *matrix, const std::size_t linear_index)

Accessor (const SparsityPatternBase *matrix)

Accessor ()

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

## Friends

class LinearIndexIterator< Iterator, Accessor >

class ChunkSparsityPatternIterators::Accessor

## Detailed Description

Accessor class for iterators into sparsity patterns. This class is also the base class for both const and non-const accessor classes into sparse matrices.

Note that this class only allows read access to elements, providing their row and column number (or alternatively the index within the complete sparsity pattern). It does not allow modifying the sparsity pattern itself.

Definition at line 131 of file sparsity_pattern.h.

## ◆ size_type

Size type of SparsityPattern.

Definition at line 137 of file sparsity_pattern.h.

## ◆ Accessor() [1/3]

 SparsityPatternIterators::Accessor::Accessor ( const SparsityPatternBase * matrix, const std::size_t linear_index )

Constructor.

## ◆ Accessor() [2/3]

 SparsityPatternIterators::Accessor::Accessor ( const SparsityPatternBase * matrix )

Constructor. Construct the end accessor for the given sparsity pattern.

## ◆ Accessor() [3/3]

 SparsityPatternIterators::Accessor::Accessor ( )

Default constructor creating a dummy accessor. This constructor is here only to be able to store accessors in STL containers such as std::vector.

## ◆ row()

 size_type SparsityPatternIterators::Accessor::row ( ) const

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

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

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

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

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

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

## ◆ operator<()

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

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.

protected

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

## ◆ LinearIndexIterator< Iterator, Accessor >

 friend class LinearIndexIterator< Iterator, Accessor >
friend

Definition at line 246 of file sparsity_pattern.h.

## ◆ ChunkSparsityPatternIterators::Accessor

 friend class ChunkSparsityPatternIterators::Accessor
friend

Definition at line 249 of file sparsity_pattern.h.

## ◆ container

 const SparsityPatternBase* SparsityPatternIterators::Accessor::container
protected

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
protected

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: