N-dimensional array line iterator. More...

#include <cartobase/containers/nditerator.h>

Inheritance diagram for carto::line_NDIterator< T >:

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. More...

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

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

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

long	line_length () const
	line_size * line stride: end of line More...

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< size_t > &strides, bool optimize_direction=false)

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

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

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

uint64_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

long	_line_stride

bool	_contiguous

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

std::vector< size_t >	_strides

std::vector< int >	_position

uint64_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< size_t >	to_int_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<int> strdes;
// 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 200 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 585 of file nditerator.h.

◆ 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 593 of file nditerator.h.

◆ line_NDIterator() [3/4]

template<typename T >

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

inline

Definition at line 604 of file nditerator.h.

◆ line_NDIterator() [4/4]

template<typename T >

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

Definition at line 631 of file nditerator.h.

Member Data Documentation

◆ _buffer

template<typename T >

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

protected

Definition at line 230 of file nditerator.h.

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

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

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

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