layout

Defined in xtensor/xlayout.hpp

enum xt::layout_type

layout_type enum for xcontainer based xexpressions

Values:

dynamic = 0x00

dynamic layout_type: you can reshape to row major, column major, or use custom strides

any = 0xFF

layout_type compatible with all others

row_major = 0x01

row major layout_type

column_major = 0x02

column major layout_type

template <class… Args>
constexpr layout_type xt::compute_layout(Args... args)

Implementation of the following logical table: 

  | d | a | r | c |
--+---+---+---+---+
d | d | d | d | d |
a | d | a | r | c |
r | d | r | r | d |
c | d | c | d | c |
d = dynamic, a = any, r = row_major, c = column_major.
Using bitmasks to avoid nested if-else statements.

Return
the output layout, computed with the previous logical table.
Parameters
  • args: the input layouts.

xcontainer

Defined in xtensor/xcontainer.hpp

template <class D>
class xt::xcontainer

Base class for dense multidimensional containers.

The xcontainer class defines the interface for dense multidimensional container classes. It does not embed any data container, this responsibility is delegated to the inheriting classes.

Template Parameters
  • D: The derived type, i.e. the inheriting class for which xcontainer provides the interface.

Inherits from xt::xiterable< D >

Subclassed by xt::xstrided_container< D >

Size and shape

auto size() const

Returns the number of element in the container.

constexpr auto dimension() const

Returns the number of dimensions of the container.

auto shape() const

Returns the shape of the container.

auto strides() const

Returns the strides of the container.

auto backstrides() const

Returns the backstrides of the container.

Data

auto operator[](const xindex &index)

Returns a reference to the element at the specified position in the container.

Parameters
  • index: a sequence of indices specifying the position in the container. Indices must be unsigned integers, the number of indices in the list should be equal or greater than the number of dimensions of the container.

auto operator[](const xindex &index) const

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

Parameters
  • index: a sequence of indices specifying the position in the container. Indices must be unsigned integers, the number of indices in the list should be equal or greater than the number of dimensions of the container.

auto data()

Returns a reference to the buffer containing the elements of the container.

auto data() const

Returns a constant reference to the buffer containing the elements of the container.

auto raw_data()

Returns the offset to the first element in the container.

auto raw_data_offset() const

Returns the offset to the first element in the container.

template <class… Args>
auto operator()(Args... args)

Returns a reference to the element at the specified position in the container.

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

template <class… Args>
auto operator()(Args... args) const

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

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

template <class… Args>
auto at(Args... args)

Returns a reference to the element at the specified position in the expression, after dimension and bounds checking.

Parameters
  • args: a list of indices specifying the position in the function. Indices must be unsigned integers, the number of indices should be equal to the number of dimensions of the expression.
Exceptions
  • std::out_of_range: if the number of argument is greater than the number of dimensions or if indices are out of bounds.

template <class… Args>
auto at(Args... args) const

Returns a constant reference to the element at the specified position in the expression, after dimension and bounds checking.

Parameters
  • args: a list of indices specifying the position in the function. Indices must be unsigned integers, the number of indices should be equal to the number of dimensions of the expression.
Exceptions
  • std::out_of_range: if the number of argument is greater than the number of dimensions or if indices are out of bounds.

template <class It>
auto element(It first, It last)

Returns a reference to the element at the specified position in the container.

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.

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

Returns a reference to the element at the specified position in the container.

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.

Broadcasting

template <class S>
bool broadcast_shape(S &shape) const

Broadcast the shape of the container to the specified parameter.

Return
a boolean indicating whether the broadcasting is trivial
Parameters
  • shape: the result shape

template <class S>
bool is_trivial_broadcast(const S &strides) const

Compares the specified strides with those of the container to see whether the broadcasting is trivial.

Return
a boolean indicating whether the broadcasting is trivial

xstrided_container

Defined in xtensor/xcontainer.hpp

template <class D>
class xt::xstrided_container

Partial implementation of xcontainer that embeds the strides and the shape.

The xstrided_container class is a partial implementation of the xcontainer interface that embed the strides and the shape of the multidimensional container. It does not embed the data container, this responsibility is delegated to the inheriting classes.

Template Parameters
  • D: The derived type, i.e. the inheriting class for which xstrided_container provides the partial imlpementation of xcontainer.

Inherits from xt::xcontainer< D >

Public Functions

template <class S = shape_type>
void reshape(const S &shape, bool force = false)

Reshapes the container.

Parameters
  • shape: the new shape
  • force: force reshaping, even if the shape stays the same (default: false)

template <class S = shape_type>
void reshape(const S &shape, layout_type l)

Reshapes the container.

Parameters
  • shape: the new shape
  • l: the new layout_type

template <class S = shape_type>
void reshape(const S &shape, const strides_type &strides)

Reshapes the container.

Parameters
  • shape: the new shape
  • strides: the new strides

layout_type layout() const

Return the layout_type of the container.

Return
layout_type of the container