Dune::ACFem::Tensor::EinsteinSummation< LeftTensor, LeftIndices, RightTensor, RightIndices, IdenticalOperands > Class Template Reference

Contraction of two tensor over a selection set of indices. More...

Collaboration diagram for Dune::ACFem::Tensor::EinsteinSummation< LeftTensor, LeftIndices, RightTensor, RightIndices, IdenticalOperands >:

Public Member Functions
template<std::size_t... Indices, std::enable_if_t<(sizeof...(Indices)==rank &&ThisType::template isZero< Indices... >()), int > = 0>
constexpr auto	operator() (Seq< Indices... >) const
	Constant access from index-sequence.
template<std::size_t... Indices, std::enable_if_t<(sizeof...(Indices)==rank &&!ThisType::template isZero< Indices... >() &&multiDim(DefectSignature{}) >=0 &&multiDim(DefectSignature{})<=Policy::TemplateForEachLimit::value), int > = 0>
constexpr auto	operator() (Seq< Indices... >) const
	Constant access from index-sequence.
template<std::size_t... Indices, std::enable_if_t<(sizeof...(Indices)==rank &&!ThisType::template isZero< Indices... >() &&multiDim(DefectSignature{}) > Policy::TemplateForEachLimit::value), int > = 0>
constexpr auto	operator() (Seq< Indices... >) const
	Constant access from index-sequence.
template<std::size_t I, std::enable_if_t<!emitByValue_< I >, int > = 0>
OperandType< I > &&	operand (IndexConstant< I >=IndexConstant< I >{}) &&
	Return one of the stored operands in an rvalue context. More...
template<std::size_t I, std::enable_if_t<!emitByValue_< I >, int > = 0>
decltype(auto)	operand (IndexConstant< I >=IndexConstant< I >{}) &
	Return one of the stored operands in a mutable reference context. More...
template<std::size_t I, std::enable_if_t<!emitByValue_< I >, int > = 0>
decltype(auto)	operand (IndexConstant< I >=IndexConstant< I >{}) const &
	Return one of the stored operands in a const reference context. More...

Static Public Attributes
template<std::size_t I>
static constexpr bool	emitByValue_ = EmitByValueV<OperandType<I> >
	Force some things to always be emitted as non-references.

Detailed Description

template<class LeftTensor, class LeftIndices, class RightTensor, class RightIndices, bool IdenticalOperands>
class Dune::ACFem::Tensor::EinsteinSummation< LeftTensor, LeftIndices, RightTensor, RightIndices, IdenticalOperands >

Contraction of two tensor over a selection set of indices.

The fancy name refers to ommitting the sum symbols in tensor contraction formulas (Einstein convention).

In formulars, compute the component-wise product "*[i][j]" over selected indices:

\[ (A *[i][j] B)_{a0,a1,b0,b1} := \sum_{i} A_{a0,i,a1} B_{b0,i,b1} := A_{a0,i,a1} B_{b0,i,b1} \]

Here all indices are to be understood as (possibly empty) multi-indices. If is empty then the resulting tensor is just the dyadic product of A with B.

Parameters

LeftTensor	Left operand.
LeftIndices	The positions of the contraction indices of the left operand.
RightTensor	Right operand.
RightIndices	The positions of the contraction indices of the right operand.

Member Function Documentation

operand() [1/3]

template<class F , class... T>

template<std::size_t I, std::enable_if_t<!emitByValue_< I >, int > = 0>

decltype(auto) Dune::ACFem::Expressions::Storage< F, T >::operand ( IndexConstant< I >  = IndexConstant<I>{} ) &

inlineinherited

Return one of the stored operands in a mutable reference context.

In this case we assume that it is safe to return a reference as the storage container should be alive in a real object.

As a special exception operands for which IsTypedValue evaluates to std::true_type are always returned as copy. It is assumed that those do not contain any runtime information.

operand() [2/3]

template<class F , class... T>

template<std::size_t I, std::enable_if_t<!emitByValue_< I >, int > = 0>

OperandType<I>&& Dune::ACFem::Expressions::Storage< F, T >::operand ( IndexConstant< I >  = IndexConstant<I>{} ) &&

inlineinherited

Return one of the stored operands in an rvalue context.

In this case exactly the contained type is returned, i.e. a copy for objects or a reference for references.

As a special exception operands for which IsTypedValue evaluates to std::true_type are always returned as copy. It is assumed that those do not contain any runtime information.

operand() [3/3]

template<class F , class... T>

template<std::size_t I, std::enable_if_t<!emitByValue_< I >, int > = 0>

decltype(auto) Dune::ACFem::Expressions::Storage< F, T >::operand ( IndexConstant< I >  = IndexConstant<I>{} ) const &

inlineinherited

Return one of the stored operands in a const reference context.

In this case we assume that it is safe to return a reference as the storage container should be alive in a real object.

As a special exception operands for which IsTypedValue evaluates to std::true_type are always returned as copy. It is assumed that those do not contain any runtime information.

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

• dune/acfem/tensors/operations/einsum.hh