codi::AggregatedTypeVectorAccessWrapper< T_Type, typename > Struct Template Reference

Generalized wrapper of the VectorAccessInterface for aggregated data types, e.g. std::complex<codi::RealReverse>. More...

#include <aggregatedTypeVectorAccessWrapper.hpp>

Inheritance diagram for codi::AggregatedTypeVectorAccessWrapper< T_Type, typename >:

Public Types
using	Type = T_Type
	See AggregatedTypeVectorAccessWrapperBase.
Public Types inherited from codi::VectorAccessInterface< int, int >
using	Identifier
	See VectorAccessInterface.
using	Real
	See VectorAccessInterface.

Additional Inherited Members
Public Member Functions inherited from codi::VectorAccessInterface< int, int >
virtual	~VectorAccessInterface ()
	Destructor.
virtual size_t	getVectorSize () const=0
	Vector size in the current tape evaluation.
virtual bool	isLhsZero ()=0
	True if the adjoint set with setLhsAdjoint is zero.
virtual VectorAccessInterface *	clone () const=0
virtual void	setLhsAdjoint (Identifier const &index)=0
virtual void	updateAdjointWithLhs (Identifier const &index, Real const &jacobian)=0
virtual void	setLhsTangent (Identifier const &index)=0
virtual void	updateTangentWithLhs (Identifier const &index, Real const &jacobian)=0
virtual void	resetAdjoint (Identifier const &index, size_t dim)=0
	Set the adjoint component to zero.
virtual void	resetAdjointVec (Identifier const &index)=0
	Set the adjoint entry to zero.
virtual Real	getAdjoint (Identifier const &index, size_t dim)=0
	Get the adjoint component.
virtual void	getAdjointVec (Identifier const &index, Real *const vec)=0
	Get the adjoint entry.
virtual Real const *	getAdjointVec (Identifier const &index)=0
	Get the adjoint entry.
virtual void	updateAdjoint (Identifier const &index, size_t dim, Real const &adjoint)=0
	Update the adjoint component.
virtual void	updateAdjointVec (Identifier const &index, Real const *const vec)=0
	Update the adjoint entry.
virtual void	setPrimal (Identifier const &index, Real const &primal)=0
	Set the primal value.
virtual Real	getPrimal (Identifier const &index)=0
	Get the primal value.
virtual bool	hasPrimals ()=0
	True if the tape/vector interface has primal values.

Detailed Description

template<typename T_Type, typename = void>
struct codi::AggregatedTypeVectorAccessWrapper< T_Type, typename >

Generalized wrapper of the VectorAccessInterface for aggregated data types, e.g. std::complex<codi::RealReverse>.

This wrapper is instantiated by AggregatedTypeVectorAccessWrapperFactory. It can be specialized for arbitrary types that consist of CoDiPack types.

This class helps to write generalized external function, that handles aggregated data types. E.g. for std::complex<codi::RealReverse> the primal value as well as the adjoint value are defined as std::complex<double> and the identifier type is defined as std::complex<int>. Since this can be different for other types like vectors or matrices, this wrapper can be used to write generalized code, that works for arbitrary aggregated types. See RealTraits::DataExtraction for a generalized access to the primal and identifier data of aggregated types.

Here is an example for a generalized external function routine (documentation/examples/Example_20_Aggregated_active_type_handling.cpp):

template<typename Type>
void extFunc_rev(Tape* t, void* d, codi::VectorAccessInterface<RealBase, Identifier>* va) {
  codi::ExternalFunctionUserData* data = (codi::ExternalFunctionUserData*)d;
 
  // Step 3: Create a wrapped vector access interface.
  using Factory = codi::AggregatedTypeVectorAccessWrapperFactory<Type>;
  using VectorWrapper = typename Factory::RType;
  VectorWrapper* vaType = Factory::create(va);
 
  using TypeIdentifier = typename VectorWrapper::Identifier;
  using TypeReal = typename VectorWrapper::Real;
 
  // Step 4: Get the external function data
  TypeReal x_v = data->getData<TypeReal>();
  TypeIdentifier x_i = data->getData<TypeIdentifier>();
  TypeIdentifier w_i = data->getData<TypeIdentifier>();
 
  // Step 5: Use the wrapped vector access interface and perform the adjoint operation
  TypeReal w_b = vaType->getAdjoint(w_i, 0);
  TypeReal t_b = 2.0 * codi::ComputationTraits::transpose(x_v) * w_b;
 
  vaType->updateAdjoint(x_i, 0, t_b);
  vaType->resetAdjoint(w_i, 0);
 
  // Step 6: Delete the created wrapper.
  Factory::destroy(vaType);
}
 
void extFunc_del(Tape* t, void* d) {
  codi::ExternalFunctionUserData* data = (codi::ExternalFunctionUserData*)d;
 
  delete data;
 
  std::cout << " Reset: data is deleted." <<  std::endl;
}
 
template<typename Type>
Type addExternalFunc(Type const& x) {
 
  Tape& tape = Real::getTape();
 
  // Step 1: Perform the passive function evaluation.
  tape.setPassive();
  Type w = func(x);
  tape.setActive();
  codi::RealTraits::registerExternalFunctionOutput(w);
 
  // Step 2: Use the general access routines on the values to extract the primal and identifier data.
  codi::ExternalFunctionUserData* data = new codi::ExternalFunctionUserData();
  data->addData(codi::RealTraits::getValue(x));
  data->addData(codi::RealTraits::getIdentifier(x));
  data->addData(codi::RealTraits::getIdentifier(w));
 
  tape.pushExternalFunction(codi::ExternalFunction<Tape>::create(extFunc_rev<Type>, data, extFunc_del));
 
  return w;
}

In general all implementations of the wrapper will forward all functions calls to the VectorAccessInterface of the underlying tape. For each active type in the structure the corresponding operation should be performed.

Implementations can use AggregatedTypeVectorAccessWrapperBase which implements most of the functions from VectorAccessInterface.

Template Parameters

T_Type

An arbitrary type which consists of multiple CoDiPack types.

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

• include/codi/tools/data/aggregatedTypeVectorAccessWrapper.hpp