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< xgenerator< F, R, S > >
using	derived_type
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
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>
const_reference	operator() (Args... args) const
	Returns the evaluated element at the specified position in the function.
template<class... Args>
const_reference	unchecked (Args... args) const
	Returns a constant reference to the element at the specified position in the expression.
template<class It>
const_reference	element (It first, It last) const
	Returns a constant reference to the element at the specified position in the function.
Public Member Functions inherited from xt::xexpression< xgenerator< F, R, S > >
derived_type &	derived_cast () &noexcept
	Returns a 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
	Returns a constant iterator to the first element of the expression.
const_layout_iterator< L >	end () const noexcept
	Returns a constant iterator to the element following the last element of the expression.
const_layout_iterator< L >	cbegin () const noexcept
	Returns a constant iterator to the first element of the expression.
const_layout_iterator< L >	cend () const noexcept
	Returns a constant iterator to the element following the last element of the expression.
const_reverse_layout_iterator< L >	rbegin () const noexcept
	Returns a constant iterator to the first element of the reversed expression.
const_reverse_layout_iterator< L >	rend () const noexcept
	Returns a constant iterator to the element following the last element of the reversed expression.
const_reverse_layout_iterator< L >	crbegin () const noexcept
	Returns a constant iterator to the first element of the reversed expression.
const_reverse_layout_iterator< L >	crend () const noexcept
	Returns a constant iterator to the element following the last element of the reversed expression.
Public Member Functions inherited from xt::xconst_accessible< xgenerator< F, R, S > >
size_type	size () const noexcept(noexcept(derived_cast().shape()))
	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
	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
	Returns a constant reference to the element at the specified position in the expression.
const_reference	periodic (Args... args) const
	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 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 E, class FE = F> requires (assignable_to_expression<E, FE>)
void	assign_to (xexpression< E > &e) const noexcept
const functor_type &	functor () const noexcept
template<class OR, class OF>
rebind_t< OR, OF >	build_generator (OF &&func) const
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) &&

Additional Inherited Members
Protected Member Functions inherited from xt::xsharable_expression< xgenerator< F, R, S > >
xsharable_expression &	operator= (const xsharable_expression &)=default
Protected Member Functions inherited from xt::xexpression< xgenerator< F, R, S > >
xexpression &	operator= (const xexpression &)=default
const inner_shape_type &	get_shape () const
Protected Member Functions inherited from xt::xconst_accessible< xgenerator< F, R, S > >
xconst_accessible &	operator= (const 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 175 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 229 of file xgenerator.hpp.

Member Function Documentation

◆ assign_to()

template<class F, class R, class S>
requires (assignable_to_expression<E, FE>)

template<class E, class FE>
requires (assignable_to_expression<E, FE>)

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

inlinenoexcept

Definition at line 376 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 339 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 391 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 318 of file xgenerator.hpp.

◆ functor()

template<class F, class R, class S>

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

inlinenoexcept

Definition at line 384 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 351 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 257 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 251 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 276 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 415 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::arange

auto arange(T start, T stop, S step=1) noexcept

Generates numbers evenly spaced within given half-open interval [start, stop).

Definition xbuilder.hpp:432

Parameters

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

Definition at line 408 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 432 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 425 of file xgenerator.hpp.

◆ shape()

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 245 of file xgenerator.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 360 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 368 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);

xt::xarray
xarray_container< uvector< T, A >, L, xt::svector< typename uvector< T, A >::size_type, 4, SA, true > > xarray
Alias template on xarray_container with default parameters for data container type and shape / stride...
Definition xtensor_forward.hpp:82

Definition at line 304 of file xgenerator.hpp.

Member Data Documentation

◆ contiguous_layout

template<class F, class R, class S>

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>

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/generators/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()

◆ stepper_begin()

◆ stepper_end()

◆ unchecked()

Member Data Documentation

◆ contiguous_layout

◆ static_layout