Multidimensional function operating on indices. More...

#include <xgenerator.hpp>

Inheritance diagram for xt::xgenerator< F, R, S >:

Public Types
using	self_type = xgenerator<F, R, S>

using	functor_type = typename std::remove_reference<F>::type

using	accessible_base = xconst_accessible<self_type>

using	extension_base = extension::xgenerator_base_t<F, R, S>

using	expression_tag = typename extension_base::expression_tag

using	inner_types = xcontainer_inner_types<self_type>

using	value_type = R

using	reference = typename inner_types::reference

using	const_reference = typename inner_types::const_reference

using	pointer = value_type*

using	const_pointer = const value_type*

using	size_type = typename inner_types::size_type

using	difference_type = std::ptrdiff_t

using	iterable_base = xconst_iterable<self_type>

using	inner_shape_type = typename iterable_base::inner_shape_type

using	shape_type = inner_shape_type

using	stepper = typename iterable_base::stepper

using	const_stepper = typename iterable_base::const_stepper

using	bool_load_type = xt::bool_load_type<R>

template<class OR , class OF >
using	rebind_t = xgenerator<OF, OR, S>

Public Types inherited from xt::xexpression< D >
using	derived_type = D

Public Types inherited from xt::xconst_iterable< xgenerator< F, R, S > >
using	derived_type

using	iterable_types

using	inner_shape_type

using	stepper

using	const_stepper

using	layout_iterator

using	const_layout_iterator

using	reverse_layout_iterator

using	const_reverse_layout_iterator

using	linear_iterator

using	const_linear_iterator

using	reverse_linear_iterator

using	const_reverse_linear_iterator

using	broadcast_iterator

using	const_broadcast_iterator

using	reverse_broadcast_iterator

using	const_reverse_broadcast_iterator

using	iterator

using	const_iterator

using	reverse_iterator

using	const_reverse_iterator

Public Types inherited from xt::xconst_accessible< xgenerator< F, R, S > >
using	derived_type

using	inner_types

using	reference

using	const_reference

using	size_type

Public Member Functions
template<class... Args>
const_reference	operator() (Args... args) const

template<class... Args>
const_reference	unchecked (Args... args) const

template<class It >
const_reference	element (It first, It last) const

template<class O >
const_stepper	stepper_begin (const O &shape) const noexcept

template<class O >
const_stepper	stepper_end (const O &shape, layout_type) const noexcept

template<class OR , class OF >
rebind_t< OR, OF >	build_generator (OF &&func) const

size_type	shape (size_type index) const
	Returns the i-th dimension of the expression.

Constructor
template<class Func >
	xgenerator (Func &&f, const S &shape) noexcept
	Constructs an xgenerator applying the specified function over the given shape.

Size and shape
const inner_shape_type &	shape () const noexcept
	Returns the shape of the xgenerator.

layout_type	layout () const noexcept

bool	is_contiguous () const noexcept

Data
template<class... Args>
auto	operator() (Args... args) const -> const_reference
	Returns the evaluated element at the specified position in the function.

template<class... Args>
auto	unchecked (Args... args) const -> const_reference
	Returns a constant reference to the element at the specified position in the expression.

template<class It >
auto	element (It first, It last) const -> const_reference
	Returns a constant reference to the element at the specified position in the function.

Public Member Functions inherited from xt::xexpression< D >
derived_type &	derived_cast () &noexcept
	Returns a reference to the actual derived type of the xexpression.

const derived_type &	derived_cast () const &noexcept
	Returns a constant reference to the actual derived type of the xexpression.

derived_type	derived_cast () &&noexcept
	Returns a constant reference to the actual derived type of the xexpression.

Public Member Functions inherited from xt::xconst_iterable< xgenerator< F, R, S > >
const_layout_iterator< L >	begin () const noexcept

const_broadcast_iterator< S, L >	begin (const S &shape) const noexcept

const_layout_iterator< L >	end () const noexcept

const_broadcast_iterator< S, L >	end (const S &shape) const noexcept

const_layout_iterator< L >	cbegin () const noexcept

const_broadcast_iterator< S, L >	cbegin (const S &shape) const noexcept

const_layout_iterator< L >	cend () const noexcept

const_broadcast_iterator< S, L >	cend (const S &shape) const noexcept

const_reverse_layout_iterator< L >	rbegin () const noexcept

const_reverse_broadcast_iterator< S, L >	rbegin (const S &shape) const noexcept

const_reverse_layout_iterator< L >	rend () const noexcept

const_reverse_broadcast_iterator< S, L >	rend (const S &shape) const noexcept

const_reverse_layout_iterator< L >	crbegin () const noexcept

const_reverse_broadcast_iterator< S, L >	crbegin (const S &shape) const noexcept

const_reverse_layout_iterator< L >	crend () const noexcept

const_reverse_broadcast_iterator< S, L >	crend (const S &shape) const noexcept

auto	begin () const noexcept -> const_layout_iterator< L >
	Returns a constant iterator to the first element of the expression.

auto	end () const noexcept -> const_layout_iterator< L >
	Returns a constant iterator to the element following the last element of the expression.

auto	cbegin () const noexcept -> const_layout_iterator< L >
	Returns a constant iterator to the first element of the expression.

auto	cend () const noexcept -> const_layout_iterator< L >
	Returns a constant iterator to the element following the last element of the expression.

auto	begin (const S &shape) const noexcept -> const_broadcast_iterator< S, L >
	Returns a constant iterator to the first element of the expression.

auto	end (const S &shape) const noexcept -> const_broadcast_iterator< S, L >
	Returns a constant iterator to the element following the last element of the expression.

auto	cbegin (const S &shape) const noexcept -> const_broadcast_iterator< S, L >
	Returns a constant iterator to the first element of the expression.

auto	cend (const S &shape) const noexcept -> const_broadcast_iterator< S, L >
	Returns a constant iterator to the element following the last element of the expression.

auto	rbegin () const noexcept -> const_reverse_layout_iterator< L >
	Returns a constant iterator to the first element of the reversed expression.

auto	rend () const noexcept -> const_reverse_layout_iterator< L >
	Returns a constant iterator to the element following the last element of the reversed expression.

auto	crbegin () const noexcept -> const_reverse_layout_iterator< L >
	Returns a constant iterator to the first element of the reversed expression.

auto	crend () const noexcept -> const_reverse_layout_iterator< L >
	Returns a constant iterator to the element following the last element of the reversed expression.

auto	rbegin (const S &shape) const noexcept -> const_reverse_broadcast_iterator< S, L >
	Returns a constant iterator to the first element of the reversed expression.

auto	rend (const S &shape) const noexcept -> const_reverse_broadcast_iterator< S, L >
	Returns a constant iterator to the element following the last element of the reversed expression.

auto	crbegin (const S &shape) const noexcept -> const_reverse_broadcast_iterator< S, L >
	Returns a constant iterator to the first element of the reversed expression.

auto	crend (const S &shape) const noexcept -> const_reverse_broadcast_iterator< S, L >
	Returns a constant iterator to the element following the last element of the reversed expression.

auto	get_cbegin (bool end_index) const noexcept -> const_layout_iterator< L >

auto	get_cbegin (const S &shape, bool end_index) const noexcept -> const_broadcast_iterator< S, L >

auto	get_cend (bool end_index) const noexcept -> const_layout_iterator< L >

auto	get_cend (const S &shape, bool end_index) const noexcept -> const_broadcast_iterator< S, L >

auto	get_stepper_begin (const S &shape) const noexcept -> const_stepper

auto	get_stepper_end (const S &shape, layout_type l) const noexcept -> const_stepper

Public Member Functions inherited from xt::xconst_accessible< xgenerator< F, R, S > >
size_type	size () const noexcept
	Returns the size of the expression.

size_type	dimension () const noexcept
	Returns the number of dimensions of the expression.

size_type	shape (size_type index) const
	Returns the i-th dimension of the expression.

const_reference	at (Args... args) const

auto	at (Args... args) const -> const_reference
	Returns a constant reference to the element at the specified position in the expression, after dimension and bounds checking.

disable_integral_t< S, const_reference >	operator[] (const S &index) const

const_reference	operator[] (std::initializer_list< I > index) const

const_reference	operator[] (size_type i) const

auto	operator[] (const S &index) const -> disable_integral_t< S, const_reference >
	Returns a constant reference to the element at the specified position in the expression.

auto	operator[] (std::initializer_list< I > index) const -> const_reference

const_reference	periodic (Args... args) const

auto	periodic (Args... args) const -> const_reference
	Returns a constant reference to the element at the specified position in the expression, after applying periodicity to the indices (negative and 'overflowing' indices are changed).

bool	in_bounds (Args... args) const
	Returns `true` only if the the specified position is a valid entry in the expression.

const_reference	front () const
	Returns a constant reference to first the element of the expression.

const_reference	back () const
	Returns a constant reference to last the element of the expression.

Static Public Attributes
static constexpr layout_type	static_layout = layout_type::dynamic

static constexpr bool	contiguous_layout = false

Broadcasting
template<class O >
bool	broadcast_shape (O &shape, bool reuse_cache=false) const
	Broadcast the shape of the function to the specified parameter.

template<class O >
bool	has_linear_assign (const O &) const noexcept
	Checks whether the xgenerator can be linearly assigned to an expression with the specified strides.

template<class E , class FE = F, class = std::enable_if_t<has_assign_to<E, FE>::value>>
void	assign_to (xexpression< E > &e) const noexcept

const functor_type &	functor () const noexcept

template<class O = xt::dynamic_shape<typename shape_type::value_type>>
auto	reshape (O &&shape) const &
	Reshapes the generator and keeps old elements.

template<class O = xt::dynamic_shape<typename shape_type::value_type>>
auto	reshape (O &&shape) &&

template<class T >
auto	reshape (std::initializer_list< T > shape) const &

template<class T >
auto	reshape (std::initializer_list< T > shape) &&

template<class O >
auto	stepper_begin (const O &shape) const noexcept -> const_stepper

template<class O >
auto	stepper_end (const O &shape, layout_type) const noexcept -> const_stepper

template<class OR , class OF >
auto	build_generator (OF &&func) const -> rebind_t< OR, OF >

Additional Inherited Members
Protected Member Functions inherited from xt::xsharable_expression< xgenerator< F, R, S > >
	xsharable_expression (const xsharable_expression &)=default

	xsharable_expression (xsharable_expression &&)=default

xsharable_expression &	operator= (const xsharable_expression &)=default

xsharable_expression &	operator= (xsharable_expression &&)=default

Protected Member Functions inherited from xt::xexpression< D >
	xexpression (const xexpression &)=default

xexpression &	operator= (const xexpression &)=default

	xexpression (xexpression &&)=default

xexpression &	operator= (xexpression &&)=default

Protected Member Functions inherited from xt::xconst_iterable< xgenerator< F, R, S > >
const inner_shape_type &	get_shape () const

Protected Member Functions inherited from xt::xconst_accessible< xgenerator< F, R, S > >
	xconst_accessible (const xconst_accessible &)=default

	xconst_accessible (xconst_accessible &&)=default

xconst_accessible &	operator= (const xconst_accessible &)=default

xconst_accessible &	operator= (xconst_accessible &&)=default

Detailed Description

template<class F, class R, class S>
class xt::xgenerator< F, R, S >

Multidimensional function operating on indices.

The xgenerator class implements a multidimensional function, generating a value from the supplied indices.

Template Parameters

F	the function type
R	the return type of the function
S	the shape type of the generator

Definition at line 106 of file xgenerator.hpp.

Member Typedef Documentation

◆ accessible_base

template<class F , class R , class S >

using xt::xgenerator< F, R, S >::accessible_base = xconst_accessible<self_type>

Definition at line 116 of file xgenerator.hpp.

◆ bool_load_type

template<class F , class R , class S >

using xt::xgenerator< F, R, S >::bool_load_type = xt::bool_load_type<R>

Definition at line 136 of file xgenerator.hpp.

◆ const_pointer

template<class F , class R , class S >

using xt::xgenerator< F, R, S >::const_pointer = const value_type*

Definition at line 125 of file xgenerator.hpp.

◆ const_reference

template<class F , class R , class S >

using xt::xgenerator< F, R, S >::const_reference = typename inner_types::const_reference

Definition at line 123 of file xgenerator.hpp.

◆ const_stepper

template<class F , class R , class S >

using xt::xgenerator< F, R, S >::const_stepper = typename iterable_base::const_stepper

Definition at line 134 of file xgenerator.hpp.

◆ difference_type

template<class F , class R , class S >

using xt::xgenerator< F, R, S >::difference_type = std::ptrdiff_t

Definition at line 127 of file xgenerator.hpp.

◆ expression_tag

template<class F , class R , class S >

using xt::xgenerator< F, R, S >::expression_tag = typename extension_base::expression_tag

Definition at line 118 of file xgenerator.hpp.

◆ extension_base

template<class F , class R , class S >

using xt::xgenerator< F, R, S >::extension_base = extension::xgenerator_base_t<F, R, S>

Definition at line 117 of file xgenerator.hpp.

◆ functor_type

template<class F , class R , class S >

using xt::xgenerator< F, R, S >::functor_type = typename std::remove_reference<F>::type

Definition at line 114 of file xgenerator.hpp.

◆ inner_shape_type

template<class F , class R , class S >

using xt::xgenerator< F, R, S >::inner_shape_type = typename iterable_base::inner_shape_type

Definition at line 130 of file xgenerator.hpp.

◆ inner_types

template<class F , class R , class S >

using xt::xgenerator< F, R, S >::inner_types = xcontainer_inner_types<self_type>

Definition at line 120 of file xgenerator.hpp.

◆ iterable_base

template<class F , class R , class S >

using xt::xgenerator< F, R, S >::iterable_base = xconst_iterable<self_type>

Definition at line 129 of file xgenerator.hpp.

◆ pointer

template<class F , class R , class S >

using xt::xgenerator< F, R, S >::pointer = value_type*

Definition at line 124 of file xgenerator.hpp.

◆ rebind_t

template<class F , class R , class S >

template<class OR , class OF >

using xt::xgenerator< F, R, S >::rebind_t = xgenerator<OF, OR, S>

Definition at line 174 of file xgenerator.hpp.

◆ reference

template<class F , class R , class S >

using xt::xgenerator< F, R, S >::reference = typename inner_types::reference

Definition at line 122 of file xgenerator.hpp.

◆ self_type

template<class F , class R , class S >

using xt::xgenerator< F, R, S >::self_type = xgenerator<F, R, S>

Definition at line 113 of file xgenerator.hpp.

◆ shape_type

template<class F , class R , class S >

using xt::xgenerator< F, R, S >::shape_type = inner_shape_type

Definition at line 131 of file xgenerator.hpp.

◆ size_type

template<class F , class R , class S >

using xt::xgenerator< F, R, S >::size_type = typename inner_types::size_type

Definition at line 126 of file xgenerator.hpp.

◆ stepper

template<class F , class R , class S >

using xt::xgenerator< F, R, S >::stepper = typename iterable_base::stepper

Definition at line 133 of file xgenerator.hpp.

◆ value_type

template<class F , class R , class S >

using xt::xgenerator< F, R, S >::value_type = R

Definition at line 121 of file xgenerator.hpp.

Constructor & Destructor Documentation

◆ xgenerator()

template<class F , class R , class S >

template<class Func >

xt::xgenerator< F, R, S >::xgenerator	(	Func &&	f,
		const S &	shape )

inlinenoexcept

Constructs an xgenerator applying the specified function over the given shape.

Parameters

f	the function to apply
shape	the shape of the xgenerator

Definition at line 228 of file xgenerator.hpp.

Member Function Documentation

◆ assign_to()

template<class F , class R , class S >

template<class E , class , class >

void xt::xgenerator< F, R, S >::assign_to ( xexpression< E > & e ) const

inlinenoexcept

Definition at line 375 of file xgenerator.hpp.

◆ broadcast_shape()

template<class F , class R , class S >

template<class O >

bool xt::xgenerator< F, R, S >::broadcast_shape	(	O &	shape,
		bool	reuse_cache = false ) const

inline

Broadcast the shape of the function to the specified parameter.

Parameters

shape	the result shape
reuse_cache	parameter for internal optimization

Returns: a boolean indicating whether the broadcasting is trivial

Definition at line 338 of file xgenerator.hpp.

◆ build_generator()

template<class F , class R , class S >

template<class OR , class OF >

auto xt::xgenerator< F, R, S >::build_generator ( OF && func ) const -> rebind_t<OR, OF>

inline

Definition at line 389 of file xgenerator.hpp.

◆ element()

template<class F , class R , class S >

template<class It >

auto xt::xgenerator< F, R, S >::element	(	It	first,
		It	last ) const -> const_reference

inline

Returns a constant reference to the element at the specified position in the function.

Parameters

first	iterator starting the sequence of indices
last	iterator ending the sequence of indices The number of indices in the sequence should be equal to or greater than the number of dimensions of the container.

Definition at line 317 of file xgenerator.hpp.

◆ functor()

template<class F , class R , class S >

auto xt::xgenerator< F, R, S >::functor ( ) const

inlinenoexcept

Definition at line 382 of file xgenerator.hpp.

◆ has_linear_assign()

template<class F , class R , class S >

template<class O >

bool xt::xgenerator< F, R, S >::has_linear_assign ( const O & ) const

inlinenoexcept

Checks whether the xgenerator can be linearly assigned to an expression with the specified strides.

Returns: a boolean indicating whether a linear assign is possible

Definition at line 350 of file xgenerator.hpp.

◆ is_contiguous()

template<class F , class R , class S >

bool xt::xgenerator< F, R, S >::is_contiguous ( ) const

inlinenoexcept

Definition at line 256 of file xgenerator.hpp.

◆ layout()

template<class F , class R , class S >

layout_type xt::xgenerator< F, R, S >::layout ( ) const

inlinenoexcept

Definition at line 250 of file xgenerator.hpp.

◆ operator()()

template<class F , class R , class S >

template<class... Args>

auto xt::xgenerator< F, R, S >::operator() ( Args... args ) const -> const_reference

inline

Returns the evaluated element at the specified position in the function.

Parameters

args	a list of indices specifying the position in the function. Indices must be unsigned integers, the number of indices should be equal or greater than the number of dimensions of the function.

Definition at line 275 of file xgenerator.hpp.

◆ reshape() [1/4]

template<class F , class R , class S >

template<class O >

auto xt::xgenerator< F, R, S >::reshape ( O && shape ) &&

inline

Definition at line 413 of file xgenerator.hpp.

◆ reshape() [2/4]

template<class F , class R , class S >

template<class O >

auto xt::xgenerator< F, R, S >::reshape ( O && shape ) const &

inline

Reshapes the generator and keeps old elements.

The shape argument can have one of its value equal to -1, in this case the value is inferred from the number of elements in the generator and the remaining values in the shape.

auto a = xt::arange<double>(50).reshape({-1, 10});

//a.shape() is {5, 10}

xt::xaccumulator_functor

Definition xaccumulator.hpp:43

Parameters

shape the new shape (has to have same number of elements as the original generator)

Definition at line 406 of file xgenerator.hpp.

◆ reshape() [3/4]

template<class F , class R , class S >

template<class T >

auto xt::xgenerator< F, R, S >::reshape ( std::initializer_list< T > shape ) &&

inline

Definition at line 430 of file xgenerator.hpp.

◆ reshape() [4/4]

template<class F , class R , class S >

template<class T >

auto xt::xgenerator< F, R, S >::reshape ( std::initializer_list< T > shape ) const &

inline

Definition at line 423 of file xgenerator.hpp.

◆ shape() [1/2]

template<class F , class R , class S >

auto xt::xgenerator< F, R, S >::shape ( ) const

inlinenoexcept

Returns the shape of the xgenerator.

Definition at line 244 of file xgenerator.hpp.

◆ shape() [2/2]

template<class F , class R , class S >

auto xt::xconst_accessible< D >::shape ( size_type index ) const

inline

Returns the i-th dimension of the expression.

Definition at line 41 of file xaccessible.hpp.

◆ stepper_begin()

template<class F , class R , class S >

template<class O >

auto xt::xgenerator< F, R, S >::stepper_begin ( const O & shape ) const -> const_stepper

inlinenoexcept

Definition at line 359 of file xgenerator.hpp.

◆ stepper_end()

template<class F , class R , class S >

template<class O >

auto xt::xgenerator< F, R, S >::stepper_end	(	const O &	shape,
		layout_type	) const -> const_stepper

inlinenoexcept

Definition at line 367 of file xgenerator.hpp.

◆ unchecked()

template<class F , class R , class S >

template<class... Args>

auto xt::xgenerator< F, R, S >::unchecked ( Args... args ) const -> const_reference

inline

Returns a constant reference to the element at the specified position in the expression.

Parameters

args	a list of indices specifying the position in the expression. Indices must be unsigned integers, the number of indices must be equal to the number of dimensions of the expression, else the behavior is undefined.

Warning: This method is meant for performance, for expressions with a dynamic number of dimensions (i.e. not known at compile time). Since it may have undefined behavior (see parameters), operator() should be preferred whenever it is possible.; This method is NOT compatible with broadcasting, meaning the following code has undefined behavior:
xt::xarray<double> a = {{0, 1}, {2, 3}};

xt::xarray<double> b = {0, 1};

auto fd = a + b;

double res = fd.uncheked(0, 1);

Definition at line 303 of file xgenerator.hpp.

Member Data Documentation

◆ contiguous_layout

template<class F , class R , class S >

constexpr bool xt::xgenerator< F, R, S >::contiguous_layout = false

staticconstexpr

Definition at line 139 of file xgenerator.hpp.

◆ static_layout

template<class F , class R , class S >

constexpr layout_type xt::xgenerator< F, R, S >::static_layout = layout_type::dynamic

staticconstexpr

Definition at line 138 of file xgenerator.hpp.

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

/home/runner/work/xtensor/xtensor/include/xtensor/xgenerator.hpp

Public Types

Public Member Functions

Static Public Attributes

Broadcasting

Additional Inherited Members

Detailed Description

Member Typedef Documentation

◆ accessible_base

◆ bool_load_type

◆ const_pointer

◆ const_reference

◆ const_stepper

◆ difference_type

◆ expression_tag

◆ extension_base

◆ functor_type

◆ inner_shape_type

◆ inner_types

◆ iterable_base

◆ pointer

◆ rebind_t

◆ reference

◆ self_type

◆ shape_type

◆ size_type

◆ stepper

◆ value_type

Constructor & Destructor Documentation

◆ xgenerator()

Member Function Documentation

◆ assign_to()

◆ broadcast_shape()

◆ build_generator()

◆ element()

◆ functor()

◆ has_linear_assign()

◆ is_contiguous()

◆ layout()

◆ operator()()

◆ reshape() [1/4]

◆ reshape() [2/4]

◆ reshape() [3/4]

◆ reshape() [4/4]

◆ shape() [1/2]

◆ shape() [2/2]

◆ stepper_begin()

◆ stepper_end()

◆ unchecked()

Member Data Documentation

◆ contiguous_layout

◆ static_layout