xmasked_view¶

Defined in xtensor/xmasked_view.hpp

template<class CTD, class CTM> class xt::xmasked_view : public xt::xview_semantic<xmasked_view<CTD, CTM>>, private xt::xaccessible<xmasked_view<CTD, CTM>>, private xt::xiterable<xmasked_view<CTD, CTM>>¶

View on an xoptional_assembly or xoptional_assembly_adaptor hiding values depending on a given mask.

The xmasked_view class implements a view on an xoptional_assembly or xoptional_assembly_adaptor, it takes this xoptional_assembly and a mask as input. The mask is an xexpression containing boolean values, whenever the value of the mask is false, the optional value of xmasked_view is considered missing, otherwise it depends on the underlying xoptional_assembly.

Template Parameters

CTD: The type of expression holding the values.
CTM: The type of expression holding the mask.

Constructors

template<class D, class M> xmasked_view(D &&data, M &&mask)¶

Creates an xmasked_view, given the xoptional_assembly or xoptional_assembly_adaptor and the mask.

Parameters

data: the underlying xoptional_assembly or xoptional_assembly_adaptor
mask: the mask.

Size and shape

size_type size() const noexcept¶: Returns the number of elements in the xmasked_view.

const inner_shape_type &shape() const noexcept¶: Returns the shape of the xmasked_view.

const inner_strides_type &strides() const noexcept¶: Returns the strides of the xmasked_view.

const inner_backstrides_type &backstrides() const noexcept¶: Returns the backstrides of the xmasked_view.

layout_type layout() const noexcept¶

Return the layout_type of the xmasked_view.

Return: layout_type of the xmasked_view

template<class T> void fill(const T &value)¶

Fills the data with the given value.

Parameters

value: the value to fill the data with.

Data

data_type &value() noexcept¶: Return an expression for the values of the xmasked_view.

const data_type &value() const noexcept¶: Return a constant expression for the values of the xmasked_view.

mask_type &visible() noexcept¶: Return an expression for the mask of the xmasked_view.

const mask_type &visible() const noexcept¶: Return a constant expression for the mask of the xmasked_view.

template<class ...Args> auto operator()(Args... args) -> reference¶

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

Parameters

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

template<class ...Args> auto operator()(Args... args) const -> const_reference¶

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

Parameters

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

template<class ...Args> auto unchecked(Args... args) -> reference¶

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

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 prefered whenever it is possible.

Warning

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);

Parameters

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

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

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

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 prefered whenever it is possible.

Warning

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);

Parameters

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

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

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

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 xmasked_view.

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 xmasked_view.

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 xmasked_view.

Public Functions

template<class ...Args> auto at(Args... args) -> reference¶

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 expression. 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 -> const_reference¶

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 expression. 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 periodic(Args... args) -> reference¶

Returns a reference to the element at the specified position in the expression, after applying periodicity to the indices (negative and ‘overflowing’ indices are changed).

Parameters

args: a list of indices specifying the position in the expression. Indices must be integers, the number of indices should be equal to the number of dimensions of the expression.

template<class ...Args> 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).

Parameters

args: a list of indices specifying the position in the expression. Indices must be integers, the number of indices should be equal to the number of dimensions of the expression.