Reducing function operating over specified axes. More...

#include <xreducer.hpp>

Inheritance diagram for xt::xreducer< F, CT, X, O >:

Public Types
using	self_type = xreducer<F, CT, X, O>
using	inner_types = xcontainer_inner_types<self_type>
using	reduce_functor_type = typename inner_types::reduce_functor_type
using	init_functor_type = typename inner_types::init_functor_type
using	merge_functor_type = typename inner_types::merge_functor_type
using	xreducer_functors_type = xreducer_functors<reduce_functor_type, init_functor_type, merge_functor_type>
using	xexpression_type = typename inner_types::xexpression_type
using	axes_type = X
using	extension_base = extension::xreducer_base_t<F, CT, X, O>
using	expression_tag = typename extension_base::expression_tag
using	substepper_type = typename inner_types::substepper_type
using	value_type = typename inner_types::value_type
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 = typename xexpression_type::difference_type
using	iterable_base = xconst_iterable<self_type>
using	inner_shape_type = typename iterable_base::inner_shape_type
using	shape_type = inner_shape_type
using	dim_mapping_type = typename select_dim_mapping_type<inner_shape_type>::type
using	stepper = typename iterable_base::stepper
using	const_stepper = typename iterable_base::const_stepper
using	bool_load_type = typename xexpression_type::bool_load_type
template<class E, class Func = F, class Opts = O>
using	rebind_t = xreducer<Func, E, X, Opts>
Public Types inherited from xt::xexpression< xreducer< F, CT, X, O > >
using	derived_type
Public Types inherited from xt::xconst_iterable< xreducer< F, CT, X, O > >
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::xaccessible< xreducer< F, CT, X, O > >
using	base_type
using	derived_type
using	reference
using	size_type
Public Types inherited from xt::xconst_accessible< xreducer< F, CT, X, O > >
using	derived_type
using	inner_types
using	reference
using	const_reference
using	size_type

Public Member Functions
xreducer_functors_type	functors () const
const O &	options () const
Constructor
template<class Func, class CTA, class AX, class OX>
	xreducer (Func &&func, CTA &&e, AX &&axes, OX &&options)
	Constructs an xreducer expression applying the specified function to the given expression over the given axes.
Size and shape
const inner_shape_type &	shape () const noexcept
	Returns the shape of the expression.
layout_type	layout () const noexcept
	Returns the shape of the expression.
bool	is_contiguous () const noexcept
Data
template<class... Args>
const_reference	operator() (Args... args) const
	Returns a constant reference to the element at the specified position in the reducer.
template<class... Args>
const_reference	unchecked (Args... args) const
	Returns a constant reference to the element at the specified position in the reducer.
template<class It>
const_reference	element (It first, It last) const
	Returns a constant reference to the element at the specified position in the reducer.
const xexpression_type &	expression () const noexcept
	Returns a constant reference to the underlying expression of the reducer.
Broadcasting
template<class S>
bool	broadcast_shape (S &shape, bool reuse_cache=false) const
	Broadcast the shape of the reducer to the specified parameter.
template<class S>
bool	has_linear_assign (const S &strides) const noexcept
	Checks whether the xreducer can be linearly assigned to an expression with the specified strides.
template<class S>
const_stepper	stepper_begin (const S &shape) const noexcept
template<class S>
const_stepper	stepper_end (const S &shape, layout_type) const noexcept
template<class E>
rebind_t< E >	build_reducer (E &&e) const
template<class E, class Func, class Opts>
rebind_t< E, Func, Opts >	build_reducer (E &&e, Func &&func, Opts &&opts) const
Public Member Functions inherited from xt::xexpression< xreducer< F, CT, X, O > >
derived_type &	derived_cast () &noexcept
	Returns a reference to the actual derived type of the xexpression.
Public Member Functions inherited from xt::xconst_iterable< xreducer< F, CT, X, O > >
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::xaccessible< xreducer< F, CT, X, O > >
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	operator[] (std::initializer_list< I > index) const
const_reference	operator[] (size_type i) const
const_reference	back () const
	Returns a constant reference to last the element of the expression.
const_reference	front () const
	Returns a constant reference to first the element of 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).
Public Member Functions inherited from xt::xconst_accessible< xreducer< F, CT, X, O > >
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

Friends
class	xreducer_stepper< F, CT, X, O >

Additional Inherited Members
Protected Member Functions inherited from xt::xsharable_expression< xreducer< F, CT, X, O > >
xsharable_expression &	operator= (const xsharable_expression &)=default
Protected Member Functions inherited from xt::xexpression< xreducer< F, CT, X, O > >
xexpression &	operator= (const xexpression &)=default
const inner_shape_type &	get_shape () const
Protected Member Functions inherited from xt::xaccessible< xreducer< F, CT, X, O > >
xaccessible &	operator= (const xaccessible &)=default
Protected Member Functions inherited from xt::xconst_accessible< xreducer< F, CT, X, O > >
xconst_accessible &	operator= (const xconst_accessible &)=default

Detailed Description

template<class F, class CT, class X, class O>
class xt::xreducer< F, CT, X, O >

Reducing function operating over specified axes.

The xreducer class implements an xexpression applying a reducing function to an xexpression over the specified axes.

Template Parameters

F	a tuple of functors (class xreducer_functors or compatible)
CT	the closure type of the xexpression to reduce
X	the list of axes

The reducer's result_type is deduced from the result type of function F::reduce_functor_type when called with elements of the expression

Template Parameters

CT.

See also: reduce

Definition at line 804 of file xreducer.hpp.

Member Typedef Documentation

◆ axes_type

template<class F, class CT, class X, class O>

using xt::xreducer< F, CT, X, O >::axes_type = X

Definition at line 820 of file xreducer.hpp.

◆ bool_load_type

template<class F, class CT, class X, class O>

using xt::xreducer< F, CT, X, O >::bool_load_type = typename xexpression_type::bool_load_type

Definition at line 843 of file xreducer.hpp.

◆ const_pointer

template<class F, class CT, class X, class O>

using xt::xreducer< F, CT, X, O >::const_pointer = const value_type*

Definition at line 830 of file xreducer.hpp.

◆ const_reference

template<class F, class CT, class X, class O>

using xt::xreducer< F, CT, X, O >::const_reference = typename inner_types::const_reference

Definition at line 828 of file xreducer.hpp.

◆ const_stepper

template<class F, class CT, class X, class O>

using xt::xreducer< F, CT, X, O >::const_stepper = typename iterable_base::const_stepper

Definition at line 842 of file xreducer.hpp.

◆ difference_type

template<class F, class CT, class X, class O>

using xt::xreducer< F, CT, X, O >::difference_type = typename xexpression_type::difference_type

Definition at line 833 of file xreducer.hpp.

◆ dim_mapping_type

template<class F, class CT, class X, class O>

using xt::xreducer< F, CT, X, O >::dim_mapping_type = typename select_dim_mapping_type<inner_shape_type>::type

Definition at line 839 of file xreducer.hpp.

◆ expression_tag

template<class F, class CT, class X, class O>

using xt::xreducer< F, CT, X, O >::expression_tag = typename extension_base::expression_tag

Definition at line 823 of file xreducer.hpp.

◆ extension_base

template<class F, class CT, class X, class O>

using xt::xreducer< F, CT, X, O >::extension_base = extension::xreducer_base_t<F, CT, X, O>

Definition at line 822 of file xreducer.hpp.

◆ init_functor_type

template<class F, class CT, class X, class O>

using xt::xreducer< F, CT, X, O >::init_functor_type = typename inner_types::init_functor_type

Definition at line 815 of file xreducer.hpp.

◆ inner_shape_type

template<class F, class CT, class X, class O>

using xt::xreducer< F, CT, X, O >::inner_shape_type = typename iterable_base::inner_shape_type

Definition at line 836 of file xreducer.hpp.

◆ inner_types

template<class F, class CT, class X, class O>

using xt::xreducer< F, CT, X, O >::inner_types = xcontainer_inner_types<self_type>

Definition at line 812 of file xreducer.hpp.

◆ iterable_base

template<class F, class CT, class X, class O>

using xt::xreducer< F, CT, X, O >::iterable_base = xconst_iterable<self_type>

Definition at line 835 of file xreducer.hpp.

◆ merge_functor_type

template<class F, class CT, class X, class O>

using xt::xreducer< F, CT, X, O >::merge_functor_type = typename inner_types::merge_functor_type

Definition at line 816 of file xreducer.hpp.

◆ pointer

template<class F, class CT, class X, class O>

using xt::xreducer< F, CT, X, O >::pointer = value_type*

Definition at line 829 of file xreducer.hpp.

◆ rebind_t

template<class F, class CT, class X, class O>

template<class E, class Func = F, class Opts = O>

using xt::xreducer< F, CT, X, O >::rebind_t = xreducer<Func, E, X, Opts>

Definition at line 877 of file xreducer.hpp.

◆ reduce_functor_type

template<class F, class CT, class X, class O>

using xt::xreducer< F, CT, X, O >::reduce_functor_type = typename inner_types::reduce_functor_type

Definition at line 814 of file xreducer.hpp.

◆ reference

template<class F, class CT, class X, class O>

using xt::xreducer< F, CT, X, O >::reference = typename inner_types::reference

Definition at line 827 of file xreducer.hpp.

◆ self_type

template<class F, class CT, class X, class O>

using xt::xreducer< F, CT, X, O >::self_type = xreducer<F, CT, X, O>

Definition at line 811 of file xreducer.hpp.

◆ shape_type

template<class F, class CT, class X, class O>

using xt::xreducer< F, CT, X, O >::shape_type = inner_shape_type

Definition at line 837 of file xreducer.hpp.

◆ size_type

template<class F, class CT, class X, class O>

using xt::xreducer< F, CT, X, O >::size_type = typename inner_types::size_type

Definition at line 832 of file xreducer.hpp.

◆ stepper

template<class F, class CT, class X, class O>

using xt::xreducer< F, CT, X, O >::stepper = typename iterable_base::stepper

Definition at line 841 of file xreducer.hpp.

◆ substepper_type

template<class F, class CT, class X, class O>

using xt::xreducer< F, CT, X, O >::substepper_type = typename inner_types::substepper_type

Definition at line 825 of file xreducer.hpp.

◆ value_type

template<class F, class CT, class X, class O>

using xt::xreducer< F, CT, X, O >::value_type = typename inner_types::value_type

Definition at line 826 of file xreducer.hpp.

◆ xexpression_type

template<class F, class CT, class X, class O>

using xt::xreducer< F, CT, X, O >::xexpression_type = typename inner_types::xexpression_type

Definition at line 819 of file xreducer.hpp.

◆ xreducer_functors_type

template<class F, class CT, class X, class O>

using xt::xreducer< F, CT, X, O >::xreducer_functors_type = xreducer_functors<reduce_functor_type, init_functor_type, merge_functor_type>

Definition at line 817 of file xreducer.hpp.

Constructor & Destructor Documentation

◆ xreducer()

template<class F, class CT, class X, class O>

template<class Func, class CTA, class AX, class OX>

xt::xreducer< F, CT, X, O >::xreducer	(	Func &&	func,
		CTA &&	e,
		AX &&	axes,
		OX &&	options )

inline

Constructs an xreducer expression applying the specified function to the given expression over the given axes.

Parameters

func	the function to apply
e	the expression to reduce
axes	the axes along which the reduction is performed
options	reducer options controlling evaluation strategy and related settings

Definition at line 1406 of file xreducer.hpp.

Member Function Documentation

◆ broadcast_shape()

template<class F, class CT, class X, class O>

template<class S>

bool xt::xreducer< F, CT, X, O >::broadcast_shape	(	S &	shape,
		bool	reuse_cache = false ) const

inline

Broadcast the shape of the reducer 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 1601 of file xreducer.hpp.

◆ build_reducer() [1/2]

template<class F, class CT, class X, class O>

template<class E>

auto xt::xreducer< F, CT, X, O >::build_reducer ( E && e ) const -> rebind_t< E >

inline

Definition at line 1639 of file xreducer.hpp.

◆ build_reducer() [2/2]

template<class F, class CT, class X, class O>

template<class E, class Func, class Opts>

auto xt::xreducer< F, CT, X, O >::build_reducer	(	E &&	e,
		Func &&	func,
		Opts &&	opts ) const

inline

Definition at line 1651 of file xreducer.hpp.

◆ element()

template<class F, class CT, class X, class O>

template<class It>

auto xt::xreducer< F, CT, X, O >::element	(	It	first,
		It	last ) const -> const_reference

inline

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

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 reducer.

Definition at line 1552 of file xreducer.hpp.

◆ expression()

template<class F, class CT, class X, class O>

auto xt::xreducer< F, CT, X, O >::expression ( ) const

inlinenoexcept

Returns a constant reference to the underlying expression of the reducer.

Definition at line 1582 of file xreducer.hpp.

◆ functors()

template<class F, class CT, class X, class O>

xreducer_functors_type xt::xreducer< F, CT, X, O >::functors ( ) const

inline

Definition at line 885 of file xreducer.hpp.

◆ has_linear_assign()

template<class F, class CT, class X, class O>

template<class S>

bool xt::xreducer< F, CT, X, O >::has_linear_assign ( const S & strides ) const

inlinenoexcept

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

Returns: a boolean indicating whether a linear assign is possible

Definition at line 1613 of file xreducer.hpp.

◆ is_contiguous()

template<class F, class CT, class X, class O>

bool xt::xreducer< F, CT, X, O >::is_contiguous ( ) const

inlinenoexcept

Definition at line 1489 of file xreducer.hpp.

◆ layout()

template<class F, class CT, class X, class O>

layout_type xt::xreducer< F, CT, X, O >::layout ( ) const

inlinenoexcept

Returns the shape of the expression.

Definition at line 1483 of file xreducer.hpp.

◆ operator()()

template<class F, class CT, class X, class O>

template<class... Args>

auto xt::xreducer< F, CT, X, O >::operator() ( Args... args ) const -> const_reference

inline

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

Parameters

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

Definition at line 1508 of file xreducer.hpp.

◆ options()

template<class F, class CT, class X, class O>

const O & xt::xreducer< F, CT, X, O >::options ( ) const

inline

Definition at line 892 of file xreducer.hpp.

◆ shape()

template<class F, class CT, class X, class O>

auto xt::xreducer< F, CT, X, O >::shape ( ) const

inlinenoexcept

Returns the shape of the expression.

Definition at line 1474 of file xreducer.hpp.

◆ stepper_begin()

template<class F, class CT, class X, class O>

template<class S>

auto xt::xreducer< F, CT, X, O >::stepper_begin ( const S & shape ) const -> const_stepper

inlinenoexcept

Definition at line 1622 of file xreducer.hpp.

◆ stepper_end()

template<class F, class CT, class X, class O>

template<class S>

auto xt::xreducer< F, CT, X, O >::stepper_end	(	const S &	shape,
		layout_type	l ) const -> const_stepper

inlinenoexcept

Definition at line 1630 of file xreducer.hpp.

◆ unchecked()

template<class F, class CT, class X, class O>

template<class... Args>

auto xt::xreducer< F, CT, X, O >::unchecked ( Args... args ) const -> const_reference

inline

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

Parameters

args	a list of indices specifying the position in the reducer. Indices must be unsigned integers, the number of indices must be equal to the number of dimensions of the reducer, 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 1537 of file xreducer.hpp.

◆ xreducer_stepper< F, CT, X, O >

template<class F, class CT, class X, class O>

friend class xreducer_stepper< F, CT, X, O >

friend

Definition at line 906 of file xreducer.hpp.

Member Data Documentation

◆ contiguous_layout

template<class F, class CT, class X, class O>

bool xt::xreducer< F, CT, X, O >::contiguous_layout = false

staticconstexpr

Definition at line 846 of file xreducer.hpp.

◆ static_layout

template<class F, class CT, class X, class O>

layout_type xt::xreducer< F, CT, X, O >::static_layout = layout_type::dynamic

staticconstexpr

Definition at line 845 of file xreducer.hpp.

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

/home/runner/work/xtensor/xtensor/include/xtensor/io/xmime.hpp
/home/runner/work/xtensor/xtensor/include/xtensor/reducers/xreducer.hpp

Public Types

Public Member Functions

Static Public Attributes

Friends

Additional Inherited Members

Detailed Description

Member Typedef Documentation

◆ axes_type

◆ bool_load_type

◆ const_pointer

◆ const_reference

◆ const_stepper

◆ difference_type

◆ dim_mapping_type

◆ expression_tag

◆ extension_base

◆ init_functor_type

◆ inner_shape_type

◆ inner_types

◆ iterable_base

◆ merge_functor_type

◆ pointer

◆ rebind_t

◆ reduce_functor_type

◆ reference

◆ self_type

◆ shape_type

◆ size_type

◆ stepper

◆ substepper_type

◆ value_type

◆ xexpression_type

◆ xreducer_functors_type

Constructor & Destructor Documentation

◆ xreducer()

Member Function Documentation

◆ broadcast_shape()

◆ build_reducer() [1/2]

◆ build_reducer() [2/2]

◆ element()

◆ expression()

◆ functors()

◆ has_linear_assign()

◆ is_contiguous()

◆ layout()

◆ operator()()

◆ options()

◆ shape()

◆ stepper_begin()

◆ stepper_end()

◆ unchecked()

Friends And Related Symbol Documentation

◆ xreducer_stepper< F, CT, X, O >

Member Data Documentation

◆ contiguous_layout

◆ static_layout