DynamicSparsityPatternIterators::Iterator Class Reference

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

Public Member Functions
	Iterator (const DynamicSparsityPattern *sp, const size_type row, const unsigned int index_within_row)
	Iterator (const DynamicSparsityPattern *sp)
	Iterator ()=default
Iterator &	operator++ ()
Iterator	operator++ (int)
const Accessor &	operator* () const
const Accessor *	operator-> () const
bool	operator== (const Iterator &) const
bool	operator!= (const Iterator &) const
bool	operator< (const Iterator &) const
int	operator- (const Iterator &p) const

Private Attributes
Accessor	accessor

Detailed Description

An iterator class for walking over the elements of a sparsity pattern.

The typical use for these iterators is to iterate over the elements of a sparsity pattern (or, since they also serve as the basis for iterating over the elements of an associated matrix, over the elements of a sparse matrix), or over the elements of individual rows. There is no guarantee that the elements of a row are actually traversed in an order in which column numbers monotonically increase. See the documentation of the SparsityPattern class for more information.

Note

This class operates directly on the internal data structures of the DynamicSparsityPattern class. As a consequence, some operations are cheap and some are not. In particular, it is cheap to access the column index of the sparsity pattern entry pointed to. On the other hand, it is expensive to compute the distance between two iterators. As a consequence, when you design algorithms that use these iterators, it is common practice to not loop over all elements of a sparsity pattern at once, but to have an outer loop over all rows and within this loop iterate over the elements of this row. This way, you only ever need to dereference the iterator to obtain the column indices whereas the (expensive) lookup of the row index can be avoided by using the loop index instead.

Definition at line 189 of file dynamic_sparsity_pattern.h.

Constructor & Destructor Documentation

Iterator() [1/3]

DynamicSparsityPatternIterators::Iterator::Iterator ( const DynamicSparsityPattern * sp, const size_type row, const unsigned int index_within_row )

inline

Constructor. Create an iterator into the sparsity pattern sp for the given global index (i.e., the index of the given element counting from the zeroth row).

Definition at line 893 of file dynamic_sparsity_pattern.h.

Iterator() [2/3]

DynamicSparsityPatternIterators::Iterator::Iterator ( const DynamicSparsityPattern * sp )

inline

Constructor. Create an invalid (end) iterator into the sparsity pattern sp.

Definition at line 901 of file dynamic_sparsity_pattern.h.

Iterator() [3/3]

DynamicSparsityPatternIterators::Iterator::Iterator ( )

default

Default constructor creating an invalid iterator. This constructor is here only to be able to store iterators in STL containers such as std::vector.

Member Function Documentation

operator++() [1/2]

Iterator & DynamicSparsityPatternIterators::Iterator::operator++ ( )

inline

Prefix increment.

Definition at line 908 of file dynamic_sparsity_pattern.h.

operator++() [2/2]

Iterator DynamicSparsityPatternIterators::Iterator::operator++ ( int )

inline

Postfix increment.

Definition at line 917 of file dynamic_sparsity_pattern.h.

operator*()

const Accessor & DynamicSparsityPatternIterators::Iterator::operator* ( ) const

inline

Dereferencing operator.

Definition at line 927 of file dynamic_sparsity_pattern.h.

operator->()

const Accessor * DynamicSparsityPatternIterators::Iterator::operator-> ( ) const

inline

Dereferencing operator.

Definition at line 935 of file dynamic_sparsity_pattern.h.

operator==()

bool DynamicSparsityPatternIterators::Iterator::operator== ( const Iterator & other ) const

inline

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

Definition at line 942 of file dynamic_sparsity_pattern.h.

operator!=()

bool DynamicSparsityPatternIterators::Iterator::operator!= ( const Iterator & other ) const

inline

Inverse of ==.

Definition at line 950 of file dynamic_sparsity_pattern.h.

operator<()

bool DynamicSparsityPatternIterators::Iterator::operator< ( const Iterator & other ) const

inline

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 matrix.

Definition at line 956 of file dynamic_sparsity_pattern.h.

operator-()

int DynamicSparsityPatternIterators::Iterator::operator- ( const Iterator & p ) const

inline

Return the distance between the current iterator and the argument. The distance is given by how many times one has to apply operator++ to the current iterator to get the argument (for a positive return value), or operator-- (for a negative return value).

Definition at line 964 of file dynamic_sparsity_pattern.h.

Member Data Documentation

accessor

Accessor DynamicSparsityPatternIterators::Iterator::accessor

private

Store an object of the accessor class.

Definition at line 273 of file dynamic_sparsity_pattern.h.

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

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