codi::IdentifierInformationTapeInterface< T_Real, T_Gradient, T_Identifier > Struct Template Reference

General information about the identifiers and checks if variables are active. More...

#include <identifierInformationTapeInterface.hpp>

Inheritance diagram for codi::IdentifierInformationTapeInterface< T_Real, T_Gradient, T_Identifier >:

Public Types
using	Gradient = T_Gradient
	See IdentifierInformationTapeInterface.
using	Identifier = T_Identifier
	See IdentifierInformationTapeInterface.
using	Real = T_Real
	See IdentifierInformationTapeInterface.

Interface definition
static bool constexpr	LinearIndexHandling = false
Identifier	getPassiveIndex () const
	Identifier for passive values. Usually 0.
Identifier	getInvalidIndex () const
	Invalid identifier.
bool	isIdentifierActive (Identifier const &index) const
template<typename Lhs , typename Tape >
void	deactivateValue (LhsExpressionInterface< Real, Gradient, Tape, Lhs > &value)

Detailed Description

template<typename T_Real, typename T_Gradient, typename T_Identifier>
struct codi::IdentifierInformationTapeInterface< T_Real, T_Gradient, T_Identifier >

General information about the identifiers and checks if variables are active.

See Tape Interface Design for a general overview of the tape interface design in CoDiPack.

With this interface, the user can check if a variable in the program is active or not. For an explanation of what is an active variable for CoDiPack, please see Online activity analysis.

Here is an example for deactivating an identifier (documentation/examples/identifierInformationTapeInterface.cpp):

  using Real = codi::RealReverse;
  using Tape = typename Real::Tape;
 
  Tape& tape = Real::getTape();
 
  tape.setActive();
 
  Real x = 200.0;
  std::cout << "Passive x: " << x.getIdentifier() << " " << tape.isIdentifierActive(x.getIdentifier()) << std::endl;
  tape.registerInput(x);
  std::cout << "Active x: " << x.getIdentifier() << " " << tape.isIdentifierActive(x.getIdentifier()) << std::endl;
  tape.deactivateValue(x);
  std::cout << "Passive x: " << x.getIdentifier() << " " << tape.isIdentifierActive(x.getIdentifier()) << std::endl;

Template Parameters

T_Real	The computation type of a tape, usually chosen as ActiveType::Real.
T_Gradient	The gradient type of a tape, usually chosen as ActiveType::Gradient.
T_Identifier	The adjoint/tangent identification type of a tape, usually chosen as ActiveType::Identifier.

Member Function Documentation

deactivateValue()

template<typename T_Real , typename T_Gradient , typename T_Identifier >

template<typename Lhs , typename Tape >

void codi::IdentifierInformationTapeInterface< T_Real, T_Gradient, T_Identifier >::deactivateValue

(

LhsExpressionInterface< Real, Gradient, Tape, Lhs > &

value

)

Modify the value such that it is no longer active.

Template Parameters

Lhs	Class that implements the LhsExpressionInterface. See also LhsExpressionInterface.
Tape	Tape implementation used in the LhsExpressionInterface. See also LhsExpressionInterface.

isIdentifierActive()

template<typename T_Real , typename T_Gradient , typename T_Identifier >

bool codi::IdentifierInformationTapeInterface< T_Real, T_Gradient, T_Identifier >::isIdentifierActive

(

Identifier const &

index

)

const

True if the identifier is considered active by the tape.

Member Data Documentation

LinearIndexHandling

template<typename T_Real , typename T_Gradient , typename T_Identifier >

bool constexpr codi::IdentifierInformationTapeInterface< T_Real, T_Gradient, T_Identifier >::LinearIndexHandling = false

staticconstexpr

True if the tape uses an index handler that provides identifiers in a monotonically increasing way (see LinearIndexManager).

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

• include/codi/tapes/interfaces/identifierInformationTapeInterface.hpp