N-dimensional array line iterator. More...

#include <cartobase/containers/nditerator.h>

Inheritance diagram for carto::line_NDIterator< T >:

[legend]

Collaboration diagram for carto::line_NDIterator< T >:

[legend]

Public Member Functions
	line_NDIterator (T *buffer, const std::vector< int > &dims)

	line_NDIterator (T *buffer, const std::vector< int > &dims, const std::vector< int > &strides, bool optimize_direction=false)
	the optional "optimize_direction" parameter allows the iterator to find a contiguous direction (with a stride == 1) and use it as the line dimension.

	line_NDIterator (T *buffer, const std::vector< int > &dims, const std::vector< std::size_t > &strides, bool optimize_direction=false)

	line_NDIterator (T *buffer, const std::vector< int > &dims, const std::vector< std::ptrdiff_t > &strides, bool optimize_direction=false)

T &	operator* () const

T *	operator-> () const

void	inc_line_ptr (T *&p) const
	increment a "line" pointer (advancing through the line)

void	inc_line_ptr (const T *&p) const
	increment a "line" pointer (advancing through the line)

std::ptrdiff_t	line_length () const
	line_size * line stride: end of line

Public Member Functions inherited from carto::line_NDIterator_base
	line_NDIterator_base (const std::vector< int > &dims)

	line_NDIterator_base (const std::vector< int > &dims, const std::vector< int > &strides, bool optimize_direction=false)

	line_NDIterator_base (const std::vector< int > &dims, const std::vector< std::size_t > &strides, bool optimize_direction=false)

	line_NDIterator_base (const std::vector< int > &dims, const std::vector< std::ptrdiff_t > &strides, bool optimize_direction=false)

NDIterator_base &	operator++ ()

int	line_size () const

int	line_direction () const

bool	is_contiguous () const

Public Member Functions inherited from carto::NDIterator_base
	NDIterator_base (const std::vector< int > &dims)

	NDIterator_base (const std::vector< int > &dims, const std::vector< int > &strides)

	NDIterator_base (const std::vector< int > &dims, const std::vector< std::size_t > &strides)

	NDIterator_base (const std::vector< int > &dims, const std::vector< std::ptrdiff_t > &strides)

const std::vector< int > &	position () const

std::ptrdiff_t	offset () const

NDIterator_base &	operator++ ()

bool	ended () const

void	reset ()

Protected Attributes
T *	_buffer

Protected Attributes inherited from carto::line_NDIterator_base
int	_line_directon

std::ptrdiff_t	_line_stride

bool	_contiguous

Protected Attributes inherited from carto::NDIterator_base
std::vector< int >	_dims

std::vector< std::ptrdiff_t >	_strides

std::vector< int >	_position

std::ptrdiff_t	_offset

bool	_ended

Additional Inherited Members
Protected Member Functions inherited from carto::line_NDIterator_base
void	set_optimized_direction (bool optimize_direction=false)

Static Protected Member Functions inherited from carto::NDIterator_base
template<typename T>
static std::vector< std::ptrdiff_t >	to_ptrdiff_v (const std::vector< T > &v)

Detailed Description

template<typename T>
class carto::line_NDIterator< T >

N-dimensional array line iterator.

Iterates over every "line" of a N-D array, using strides. The "lines" are arrays over the smallest dimension of the array. Thus the iterator iterates over all dimensions but the smallest one. This allows to optimize code iterating directly on the smallest dimension, which is much more efficient than the regular NDIterator: for a very simple item operation using a line_NDIterator instead of a NDIterator can be about 20 times faster.

float *data; // fill it...
std::vector<int> dimensions;
std::vector<std::ptrdiff_t> strides;
// fill dimensions and strides...
float sum = 0.;
line_NDIterator<float> it( data, dimensions, strides );
float *p, *pp;
for( ; !it.ended(); ++it )
{
  p = &*it;
  for( pp=p + it.line_length(); p!=pp; it.inc_line_ptr( p ) )
    sum += *p;
}

Definition at line 201 of file nditerator.h.

Constructor & Destructor Documentation

◆ line_NDIterator() [1/4]

template<typename T>

carto::line_NDIterator< T >::line_NDIterator	(	T *	buffer,
		const std::vector< int > &	dims )

inline

Definition at line 583 of file nditerator.h.

References _buffer, and carto::line_NDIterator_base::line_NDIterator_base().

◆ line_NDIterator() [2/4]

template<typename T>

carto::line_NDIterator< T >::line_NDIterator	(	T *	buffer,
		const std::vector< int > &	dims,
		const std::vector< int > &	strides,
		bool	optimize_direction = false )

inline

the optional "optimize_direction" parameter allows the iterator to find a contiguous direction (with a stride == 1) and use it as the line dimension.

This way a line pointer can be incremented instead of adding strides. In many cases it does not change much in performance.

Definition at line 591 of file nditerator.h.

References _buffer, and carto::line_NDIterator_base::line_NDIterator_base().

◆ line_NDIterator() [3/4]

template<typename T>

carto::line_NDIterator< T >::line_NDIterator	(	T *	buffer,
		const std::vector< int > &	dims,
		const std::vector< std::size_t > &	strides,
		bool	optimize_direction = false )

inline

Definition at line 602 of file nditerator.h.

References _buffer, and carto::line_NDIterator_base::line_NDIterator_base().

◆ line_NDIterator() [4/4]

template<typename T>

carto::line_NDIterator< T >::line_NDIterator	(	T *	buffer,
		const std::vector< int > &	dims,
		const std::vector< std::ptrdiff_t > &	strides,
		bool	optimize_direction = false )

inline

Definition at line 613 of file nditerator.h.

References _buffer, and carto::line_NDIterator_base::line_NDIterator_base().

Member Function Documentation

◆ inc_line_ptr() [1/2]

template<typename T>

void carto::line_NDIterator< T >::inc_line_ptr ( const T *& p ) const

inline

increment a "line" pointer (advancing through the line)

Definition at line 646 of file nditerator.h.

References carto::line_NDIterator_base::_contiguous, and carto::line_NDIterator_base::_line_stride.

◆ inc_line_ptr() [2/2]

template<typename T>

void carto::line_NDIterator< T >::inc_line_ptr ( T *& p ) const

inline

increment a "line" pointer (advancing through the line)

Definition at line 636 of file nditerator.h.

References carto::line_NDIterator_base::_contiguous, and carto::line_NDIterator_base::_line_stride.

◆ line_length()

template<typename T>

std::ptrdiff_t carto::line_NDIterator< T >::line_length ( ) const

inline

line_size * line stride: end of line

Definition at line 656 of file nditerator.h.

References carto::line_NDIterator_base::_line_directon, carto::NDIterator_base::_strides, carto::line_NDIterator_base::is_contiguous(), and carto::line_NDIterator_base::line_size().

◆ operator*()

template<typename T>

T & carto::line_NDIterator< T >::operator* ( ) const

inline

Definition at line 623 of file nditerator.h.

References _buffer, and carto::NDIterator_base::_offset.

◆ operator->()

template<typename T>

T * carto::line_NDIterator< T >::operator-> ( ) const

inline

Definition at line 629 of file nditerator.h.

References _buffer, and carto::NDIterator_base::_offset.

Member Data Documentation

◆ _buffer

template<typename T>

T* carto::line_NDIterator< T >::_buffer

protected

Definition at line 231 of file nditerator.h.

Referenced by line_NDIterator(), line_NDIterator(), line_NDIterator(), line_NDIterator(), operator*(), and operator->().

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

cartobase/containers/nditerator.h

Public Member Functions

Protected Attributes

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ line_NDIterator() [1/4]

◆ line_NDIterator() [2/4]

◆ line_NDIterator() [3/4]

◆ line_NDIterator() [4/4]

Member Function Documentation

◆ inc_line_ptr() [1/2]

◆ inc_line_ptr() [2/2]

◆ line_length()

◆ operator*()

◆ operator->()

Member Data Documentation

◆ _buffer