Eigen::AutoDiffScalar< _DerType > Class Template Reference

Detailed Description

template<typename _DerType>
class Eigen::AutoDiffScalar< _DerType >

A scalar type replacement with automatic differentation capability.

_DerTypethe vector type used to store/represent the derivatives. The base scalar type as well as the number of derivatives to compute are determined from this type. Typical choices include, e.g., Vector4f for 4 derivatives, or VectorXf if the number of derivatives is not known at compile time, and/or, the number of derivatives is large. Note that _DerType can also be a reference (e.g., VectorXf&) to wrap a existing vector into an AutoDiffScalar. Finally, _DerType can also be any Eigen compatible expression.

This class represents a scalar value while tracking its respective derivatives using Eigen's expression template mechanism.

It supports the following list of global math function:

  • std::abs, std::sqrt, std::pow, std::exp, std::log, std::sin, std::cos,
  • internal::abs, internal::sqrt, numext::pow, internal::exp, internal::log, internal::sin, internal::cos,
  • internal::conj, internal::real, internal::imag, numext::abs2.

AutoDiffScalar can be used as the scalar type of an Eigen::Matrix object. However, in that case, the expression template mechanism only occurs at the top Matrix level, while derivatives are computed right away.

Inherits Eigen::internal::auto_diff_special_op< _DerType, !internal::is_same< internal::traits< internal::remove_all< _DerType >::type >::Scalar, NumTraits< internal::traits< internal::remove_all< _DerType >::type >::Scalar >::Real >::value >.

Public Member Functions

 AutoDiffScalar ()
 AutoDiffScalar (const Scalar &value, int nbDer, int derNumber)
 AutoDiffScalar (const Real &value)
 AutoDiffScalar (const Scalar &value, const DerType &der)

Constructor & Destructor Documentation

◆ AutoDiffScalar() [1/4]

template<typename _DerType>
Eigen::AutoDiffScalar< _DerType >::AutoDiffScalar ( )

Default constructor without any initialization.

◆ AutoDiffScalar() [2/4]

template<typename _DerType>
Eigen::AutoDiffScalar< _DerType >::AutoDiffScalar ( const Scalar &  value,
int  nbDer,
int  derNumber 

Constructs an active scalar from its value, and initializes the nbDer derivatives such that it corresponds to the derNumber -th variable

◆ AutoDiffScalar() [3/4]

template<typename _DerType>
Eigen::AutoDiffScalar< _DerType >::AutoDiffScalar ( const Real &  value)

Conversion from a scalar constant to an active scalar. The derivatives are set to zero.

◆ AutoDiffScalar() [4/4]

template<typename _DerType>
Eigen::AutoDiffScalar< _DerType >::AutoDiffScalar ( const Scalar &  value,
const DerType &  der 

Constructs an active scalar from its value and derivatives der

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