1 // This file is part of Eigen, a lightweight C++ template library
2 // for linear algebra.
3 //
4 // Copyright (C) 2009 Gael Guennebaud <gael.guennebaud@inria.fr>
5 //
6 // This Source Code Form is subject to the terms of the Mozilla
7 // Public License v. 2.0. If a copy of the MPL was not distributed
8 // with this file, You can obtain one at http://mozilla.org/MPL/2.0/.
9 
10 #ifndef EIGEN_AUTODIFF_JACOBIAN_H
11 #define EIGEN_AUTODIFF_JACOBIAN_H
12 
13 namespace Eigen
14 {
15 
16 template<typename Functor> class AutoDiffJacobian : public Functor
17 {
18 public:
AutoDiffJacobian()19   AutoDiffJacobian() : Functor() {}
AutoDiffJacobian(const Functor & f)20   AutoDiffJacobian(const Functor& f) : Functor(f) {}
21 
22   // forward constructors
23 #if EIGEN_HAS_VARIADIC_TEMPLATES
24   template<typename... T>
AutoDiffJacobian(const T &...Values)25   AutoDiffJacobian(const T& ...Values) : Functor(Values...) {}
26 #else
27   template<typename T0>
AutoDiffJacobian(const T0 & a0)28   AutoDiffJacobian(const T0& a0) : Functor(a0) {}
29   template<typename T0, typename T1>
AutoDiffJacobian(const T0 & a0,const T1 & a1)30   AutoDiffJacobian(const T0& a0, const T1& a1) : Functor(a0, a1) {}
31   template<typename T0, typename T1, typename T2>
AutoDiffJacobian(const T0 & a0,const T1 & a1,const T2 & a2)32   AutoDiffJacobian(const T0& a0, const T1& a1, const T2& a2) : Functor(a0, a1, a2) {}
33 #endif
34 
35   typedef typename Functor::InputType InputType;
36   typedef typename Functor::ValueType ValueType;
37   typedef typename ValueType::Scalar Scalar;
38 
39   enum {
40     InputsAtCompileTime = InputType::RowsAtCompileTime,
41     ValuesAtCompileTime = ValueType::RowsAtCompileTime
42   };
43 
44   typedef Matrix<Scalar, ValuesAtCompileTime, InputsAtCompileTime> JacobianType;
45   typedef typename JacobianType::Index Index;
46 
47   typedef Matrix<Scalar, InputsAtCompileTime, 1> DerivativeType;
48   typedef AutoDiffScalar<DerivativeType> ActiveScalar;
49 
50   typedef Matrix<ActiveScalar, InputsAtCompileTime, 1> ActiveInput;
51   typedef Matrix<ActiveScalar, ValuesAtCompileTime, 1> ActiveValue;
52 
53 #if EIGEN_HAS_VARIADIC_TEMPLATES
54   // Some compilers don't accept variadic parameters after a default parameter,
55   // i.e., we can't just write _jac=0 but we need to overload operator():
56   EIGEN_STRONG_INLINE
operator()57   void operator() (const InputType& x, ValueType* v) const
58   {
59       this->operator()(x, v, 0);
60   }
61   template<typename... ParamsType>
operator()62   void operator() (const InputType& x, ValueType* v, JacobianType* _jac,
63                    const ParamsType&... Params) const
64 #else
65   void operator() (const InputType& x, ValueType* v, JacobianType* _jac=0) const
66 #endif
67   {
68     eigen_assert(v!=0);
69 
70     if (!_jac)
71     {
72 #if EIGEN_HAS_VARIADIC_TEMPLATES
73       Functor::operator()(x, v, Params...);
74 #else
75       Functor::operator()(x, v);
76 #endif
77       return;
78     }
79 
80     JacobianType& jac = *_jac;
81 
82     ActiveInput ax = x.template cast<ActiveScalar>();
83     ActiveValue av(jac.rows());
84 
85     if(InputsAtCompileTime==Dynamic)
86       for (Index j=0; j<jac.rows(); j++)
87         av[j].derivatives().resize(x.rows());
88 
89     for (Index i=0; i<jac.cols(); i++)
90       ax[i].derivatives() = DerivativeType::Unit(x.rows(),i);
91 
92 #if EIGEN_HAS_VARIADIC_TEMPLATES
93     Functor::operator()(ax, &av, Params...);
94 #else
95     Functor::operator()(ax, &av);
96 #endif
97 
98     for (Index i=0; i<jac.rows(); i++)
99     {
100       (*v)[i] = av[i].value();
101       jac.row(i) = av[i].derivatives();
102     }
103   }
104 };
105 
106 }
107 
108 #endif // EIGEN_AUTODIFF_JACOBIAN_H
109