AdolcForward

// This file is part of Eigen, a lightweight C++ template library
// for linear algebra.
//
// Copyright (C) 2008-2009 Gael Guennebaud <g.gael@free.fr>
//
// This Source Code Form is subject to the terms of the Mozilla
// Public License v. 2.0. If a copy of the MPL was not distributed
// with this file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
#ifndef EIGEN_ADLOC_FORWARD_MODULE_H
#define EIGEN_ADLOC_FORWARD_MODULE_H
 
//--------------------------------------------------------------------------------
//
// This file provides support for adolc's adouble type in forward mode.
// ADOL-C is a C++ automatic differentiation library,
// see https://projects.coin-or.org/ADOL-C for more information.
//
// Note that the maximal number of directions is controlled by
// the preprocessor token NUMBER_DIRECTIONS. The default is 2.
//
//--------------------------------------------------------------------------------
 
#define ADOLC_TAPELESS
#ifndef NUMBER_DIRECTIONS
#define NUMBER_DIRECTIONS 2
#endif
#include <adolc/adtl.h>
 
// adolc defines some very stupid macros:
#if defined(malloc)
#undef malloc
#endif
 
#if defined(calloc)
#undef calloc
#endif
 
#if defined(realloc)
#undef realloc
#endif
 
#include "../../Eigen/Core"
 
namespace Eigen {

 
}  // namespace Eigen
 
// Eigen's require a few additional functions which must be defined in the same namespace
// than the custom scalar type own namespace
namespace adtl {
 
inline const adouble& conj(const adouble& x) { return x; }
inline const adouble& real(const adouble& x) { return x; }
inline adouble imag(const adouble&) { return 0.; }
inline adouble abs(const adouble& x) { return fabs(x); }
inline adouble abs2(const adouble& x) { return x * x; }
 
inline bool(isinf)(const adouble& x) { return (Eigen::numext::isinf)(x.getValue()); }
inline bool(isnan)(const adouble& x) { return (Eigen::numext::isnan)(x.getValue()); }
 
}  // namespace adtl
 
namespace Eigen {
 
template <>
struct NumTraits<adtl::adouble> : NumTraits<double> {
  typedef adtl::adouble Real;
  typedef adtl::adouble NonInteger;
  typedef adtl::adouble Nested;
  enum {
    IsComplex = 0,
    IsInteger = 0,
    IsSigned = 1,
    RequireInitialization = 1,
    ReadCost = 1,
    AddCost = 1,
    MulCost = 1
  };
};
 
template <typename Functor>
class AdolcForwardJacobian : public Functor {
  typedef adtl::adouble ActiveScalar;
 
 public:
  AdolcForwardJacobian() : Functor() {}
  AdolcForwardJacobian(const Functor& f) : Functor(f) {}
 
  // forward constructors
  template <typename T0>
  AdolcForwardJacobian(const T0& a0) : Functor(a0) {}
  template <typename T0, typename T1>
  AdolcForwardJacobian(const T0& a0, const T1& a1) : Functor(a0, a1) {}
  template <typename T0, typename T1, typename T2>
  AdolcForwardJacobian(const T0& a0, const T1& a1, const T1& a2) : Functor(a0, a1, a2) {}
 
  typedef typename Functor::InputType InputType;
  typedef typename Functor::ValueType ValueType;
  typedef typename Functor::JacobianType JacobianType;
 
  typedef Matrix<ActiveScalar, InputType::SizeAtCompileTime, 1> ActiveInput;
  typedef Matrix<ActiveScalar, ValueType::SizeAtCompileTime, 1> ActiveValue;
 
  void operator()(const InputType& x, ValueType* v, JacobianType* _jac) const {
    eigen_assert(v != 0);
    if (!_jac) {
      Functor::operator()(x, v);
      return;
    }
 
    JacobianType& jac = *_jac;
 
    ActiveInput ax = x.template cast<ActiveScalar>();
    ActiveValue av(jac.rows());
 
    for (int j = 0; j < jac.cols(); j++)
      for (int i = 0; i < jac.cols(); i++) ax[i].setADValue(j, i == j ? 1 : 0);
 
    Functor::operator()(ax, &av);
 
    for (int i = 0; i < jac.rows(); i++) {
      (*v)[i] = av[i].getValue();
      for (int j = 0; j < jac.cols(); j++) jac.coeffRef(i, j) = av[i].getADValue(j);
    }
  }
 
 protected:
};

 
}  // namespace Eigen
 
#endif  // EIGEN_ADLOC_FORWARD_MODULE_H