xbroadcast¶
Defined in xtensor/xbroadcast.hpp
-
template<class
CT
, classX
>
classxbroadcast
: public xt::xsharable_expression<xbroadcast<CT, X>>, public xt::xconst_iterable<xbroadcast<CT, X>>, public xt::xconst_accessible<xbroadcast<CT, X>>, public extension::xbroadcast_base_t<CT, X>¶ Broadcasted xexpression to a specified shape.
The xbroadcast class implements the broadcasting of an xexpression to a specified shape. xbroadcast is not meant to be used directly, but only with the broadcast helper functions.
- See
- Template Parameters
CT
: the closure type of the xexpression to broadcastX
: the type of the specified shape.
Constructor
-
template<class
CTA
, classS
>xbroadcast
(CTA &&e, const S &s)¶ Constructs an xbroadcast expression broadcasting the specified xexpression to the given shape.
- Parameters
e
: the expression to broadcasts
: the shape to apply
-
template<class
CTA
>xbroadcast
(CTA &&e, shape_type &&s)¶ Constructs an xbroadcast expression broadcasting the specified xexpression to the given shape.
- Parameters
e
: the expression to broadcasts
: the shape to apply
Size and shape
-
auto
shape
() const¶ Returns the shape of the expression.
-
layout_type
layout
() const¶ Returns the layout_type of the expression.
Data
-
auto
expression
() const¶ Returns a constant reference to the underlying expression of the broadcast expression.
-
template<class ...
Args
>
autooperator()
(Args... args) const¶ 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 function. Indices must be unsigned integers, the number of indices should be equal or greater than the number of dimensions of the expression.
-
template<class ...
Args
>
autounchecked
(Args... args) const¶ Returns a constant reference to the element at the specified position in the expression.
- 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 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.
-
template<class
It
>
autoelement
(It, It last) const¶ Returns a constant reference to the element at the specified position in the expression.
- Parameters
first
: iterator starting the sequence of indiceslast
: 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 function.
Broadcasting
-
template<class
E
, classS
>
autoxt
::
broadcast
(E &&e, const S &s) Returns an xexpression broadcasting the given expression to a specified shape.
The returned expression either hold a const reference to
e
or a copy depending on whethere
is an lvalue or an rvalue.- Template Parameters
e
: the xexpression to broadcasts
: the specified shape to broadcast.