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_SCALAR_H
11#define EIGEN_AUTODIFF_SCALAR_H
12
13namespace Eigen {
14
15namespace internal {
16
17template<typename A, typename B>
18struct make_coherent_impl {
19  static void run(A&, B&) {}
20};
21
22// resize a to match b is a.size()==0, and conversely.
23template<typename A, typename B>
24void make_coherent(const A& a, const B&b)
25{
26  make_coherent_impl<A,B>::run(a.const_cast_derived(), b.const_cast_derived());
27}
28
29template<typename _DerType, bool Enable> struct auto_diff_special_op;
30
31} // end namespace internal
32
33/** \class AutoDiffScalar
34  * \brief A scalar type replacement with automatic differentation capability
35  *
36  * \param _DerType the vector type used to store/represent the derivatives. The base scalar type
37  *                 as well as the number of derivatives to compute are determined from this type.
38  *                 Typical choices include, e.g., \c Vector4f for 4 derivatives, or \c VectorXf
39  *                 if the number of derivatives is not known at compile time, and/or, the number
40  *                 of derivatives is large.
41  *                 Note that _DerType can also be a reference (e.g., \c VectorXf&) to wrap a
42  *                 existing vector into an AutoDiffScalar.
43  *                 Finally, _DerType can also be any Eigen compatible expression.
44  *
45  * This class represents a scalar value while tracking its respective derivatives using Eigen's expression
46  * template mechanism.
47  *
48  * It supports the following list of global math function:
49  *  - std::abs, std::sqrt, std::pow, std::exp, std::log, std::sin, std::cos,
50  *  - internal::abs, internal::sqrt, numext::pow, internal::exp, internal::log, internal::sin, internal::cos,
51  *  - internal::conj, internal::real, internal::imag, numext::abs2.
52  *
53  * AutoDiffScalar can be used as the scalar type of an Eigen::Matrix object. However,
54  * in that case, the expression template mechanism only occurs at the top Matrix level,
55  * while derivatives are computed right away.
56  *
57  */
58
59template<typename _DerType>
60class AutoDiffScalar
61  : public internal::auto_diff_special_op
62            <_DerType, !internal::is_same<typename internal::traits<typename internal::remove_all<_DerType>::type>::Scalar,
63                                        typename NumTraits<typename internal::traits<typename internal::remove_all<_DerType>::type>::Scalar>::Real>::value>
64{
65  public:
66    typedef internal::auto_diff_special_op
67            <_DerType, !internal::is_same<typename internal::traits<typename internal::remove_all<_DerType>::type>::Scalar,
68                       typename NumTraits<typename internal::traits<typename internal::remove_all<_DerType>::type>::Scalar>::Real>::value> Base;
69    typedef typename internal::remove_all<_DerType>::type DerType;
70    typedef typename internal::traits<DerType>::Scalar Scalar;
71    typedef typename NumTraits<Scalar>::Real Real;
72
73    using Base::operator+;
74    using Base::operator*;
75
76    /** Default constructor without any initialization. */
77    AutoDiffScalar() {}
78
79    /** Constructs an active scalar from its \a value,
80        and initializes the \a nbDer derivatives such that it corresponds to the \a derNumber -th variable */
81    AutoDiffScalar(const Scalar& value, int nbDer, int derNumber)
82      : m_value(value), m_derivatives(DerType::Zero(nbDer))
83    {
84      m_derivatives.coeffRef(derNumber) = Scalar(1);
85    }
86
87    /** Conversion from a scalar constant to an active scalar.
88      * The derivatives are set to zero. */
89    /*explicit*/ AutoDiffScalar(const Real& value)
90      : m_value(value)
91    {
92      if(m_derivatives.size()>0)
93        m_derivatives.setZero();
94    }
95
96    /** Constructs an active scalar from its \a value and derivatives \a der */
97    AutoDiffScalar(const Scalar& value, const DerType& der)
98      : m_value(value), m_derivatives(der)
99    {}
100
101    template<typename OtherDerType>
102    AutoDiffScalar(const AutoDiffScalar<OtherDerType>& other)
103      : m_value(other.value()), m_derivatives(other.derivatives())
104    {}
105
106    friend  std::ostream & operator << (std::ostream & s, const AutoDiffScalar& a)
107    {
108      return s << a.value();
109    }
110
111    AutoDiffScalar(const AutoDiffScalar& other)
112      : m_value(other.value()), m_derivatives(other.derivatives())
113    {}
114
115    template<typename OtherDerType>
116    inline AutoDiffScalar& operator=(const AutoDiffScalar<OtherDerType>& other)
117    {
118      m_value = other.value();
119      m_derivatives = other.derivatives();
120      return *this;
121    }
122
123    inline AutoDiffScalar& operator=(const AutoDiffScalar& other)
124    {
125      m_value = other.value();
126      m_derivatives = other.derivatives();
127      return *this;
128    }
129
130//     inline operator const Scalar& () const { return m_value; }
131//     inline operator Scalar& () { return m_value; }
132
133    inline const Scalar& value() const { return m_value; }
134    inline Scalar& value() { return m_value; }
135
136    inline const DerType& derivatives() const { return m_derivatives; }
137    inline DerType& derivatives() { return m_derivatives; }
138
139    inline bool operator< (const Scalar& other) const  { return m_value <  other; }
140    inline bool operator<=(const Scalar& other) const  { return m_value <= other; }
141    inline bool operator> (const Scalar& other) const  { return m_value >  other; }
142    inline bool operator>=(const Scalar& other) const  { return m_value >= other; }
143    inline bool operator==(const Scalar& other) const  { return m_value == other; }
144    inline bool operator!=(const Scalar& other) const  { return m_value != other; }
145
146    friend inline bool operator< (const Scalar& a, const AutoDiffScalar& b) { return a <  b.value(); }
147    friend inline bool operator<=(const Scalar& a, const AutoDiffScalar& b) { return a <= b.value(); }
148    friend inline bool operator> (const Scalar& a, const AutoDiffScalar& b) { return a >  b.value(); }
149    friend inline bool operator>=(const Scalar& a, const AutoDiffScalar& b) { return a >= b.value(); }
150    friend inline bool operator==(const Scalar& a, const AutoDiffScalar& b) { return a == b.value(); }
151    friend inline bool operator!=(const Scalar& a, const AutoDiffScalar& b) { return a != b.value(); }
152
153    template<typename OtherDerType> inline bool operator< (const AutoDiffScalar<OtherDerType>& b) const  { return m_value <  b.value(); }
154    template<typename OtherDerType> inline bool operator<=(const AutoDiffScalar<OtherDerType>& b) const  { return m_value <= b.value(); }
155    template<typename OtherDerType> inline bool operator> (const AutoDiffScalar<OtherDerType>& b) const  { return m_value >  b.value(); }
156    template<typename OtherDerType> inline bool operator>=(const AutoDiffScalar<OtherDerType>& b) const  { return m_value >= b.value(); }
157    template<typename OtherDerType> inline bool operator==(const AutoDiffScalar<OtherDerType>& b) const  { return m_value == b.value(); }
158    template<typename OtherDerType> inline bool operator!=(const AutoDiffScalar<OtherDerType>& b) const  { return m_value != b.value(); }
159
160    inline const AutoDiffScalar<DerType&> operator+(const Scalar& other) const
161    {
162      return AutoDiffScalar<DerType&>(m_value + other, m_derivatives);
163    }
164
165    friend inline const AutoDiffScalar<DerType&> operator+(const Scalar& a, const AutoDiffScalar& b)
166    {
167      return AutoDiffScalar<DerType&>(a + b.value(), b.derivatives());
168    }
169
170//     inline const AutoDiffScalar<DerType&> operator+(const Real& other) const
171//     {
172//       return AutoDiffScalar<DerType&>(m_value + other, m_derivatives);
173//     }
174
175//     friend inline const AutoDiffScalar<DerType&> operator+(const Real& a, const AutoDiffScalar& b)
176//     {
177//       return AutoDiffScalar<DerType&>(a + b.value(), b.derivatives());
178//     }
179
180    inline AutoDiffScalar& operator+=(const Scalar& other)
181    {
182      value() += other;
183      return *this;
184    }
185
186    template<typename OtherDerType>
187    inline const AutoDiffScalar<CwiseBinaryOp<internal::scalar_sum_op<Scalar>,const DerType,const typename internal::remove_all<OtherDerType>::type> >
188    operator+(const AutoDiffScalar<OtherDerType>& other) const
189    {
190      internal::make_coherent(m_derivatives, other.derivatives());
191      return AutoDiffScalar<CwiseBinaryOp<internal::scalar_sum_op<Scalar>,const DerType,const typename internal::remove_all<OtherDerType>::type> >(
192        m_value + other.value(),
193        m_derivatives + other.derivatives());
194    }
195
196    template<typename OtherDerType>
197    inline AutoDiffScalar&
198    operator+=(const AutoDiffScalar<OtherDerType>& other)
199    {
200      (*this) = (*this) + other;
201      return *this;
202    }
203
204    inline const AutoDiffScalar<DerType&> operator-(const Scalar& b) const
205    {
206      return AutoDiffScalar<DerType&>(m_value - b, m_derivatives);
207    }
208
209    friend inline const AutoDiffScalar<CwiseUnaryOp<internal::scalar_opposite_op<Scalar>, const DerType> >
210    operator-(const Scalar& a, const AutoDiffScalar& b)
211    {
212      return AutoDiffScalar<CwiseUnaryOp<internal::scalar_opposite_op<Scalar>, const DerType> >
213            (a - b.value(), -b.derivatives());
214    }
215
216    inline AutoDiffScalar& operator-=(const Scalar& other)
217    {
218      value() -= other;
219      return *this;
220    }
221
222    template<typename OtherDerType>
223    inline const AutoDiffScalar<CwiseBinaryOp<internal::scalar_difference_op<Scalar>, const DerType,const typename internal::remove_all<OtherDerType>::type> >
224    operator-(const AutoDiffScalar<OtherDerType>& other) const
225    {
226      internal::make_coherent(m_derivatives, other.derivatives());
227      return AutoDiffScalar<CwiseBinaryOp<internal::scalar_difference_op<Scalar>, const DerType,const typename internal::remove_all<OtherDerType>::type> >(
228        m_value - other.value(),
229        m_derivatives - other.derivatives());
230    }
231
232    template<typename OtherDerType>
233    inline AutoDiffScalar&
234    operator-=(const AutoDiffScalar<OtherDerType>& other)
235    {
236      *this = *this - other;
237      return *this;
238    }
239
240    inline const AutoDiffScalar<CwiseUnaryOp<internal::scalar_opposite_op<Scalar>, const DerType> >
241    operator-() const
242    {
243      return AutoDiffScalar<CwiseUnaryOp<internal::scalar_opposite_op<Scalar>, const DerType> >(
244        -m_value,
245        -m_derivatives);
246    }
247
248    inline const AutoDiffScalar<CwiseUnaryOp<internal::scalar_multiple_op<Scalar>, const DerType> >
249    operator*(const Scalar& other) const
250    {
251      return AutoDiffScalar<CwiseUnaryOp<internal::scalar_multiple_op<Scalar>, const DerType> >(
252        m_value * other,
253        (m_derivatives * other));
254    }
255
256    friend inline const AutoDiffScalar<CwiseUnaryOp<internal::scalar_multiple_op<Scalar>, const DerType> >
257    operator*(const Scalar& other, const AutoDiffScalar& a)
258    {
259      return AutoDiffScalar<CwiseUnaryOp<internal::scalar_multiple_op<Scalar>, const DerType> >(
260        a.value() * other,
261        a.derivatives() * other);
262    }
263
264//     inline const AutoDiffScalar<typename CwiseUnaryOp<internal::scalar_multiple_op<Real>, DerType>::Type >
265//     operator*(const Real& other) const
266//     {
267//       return AutoDiffScalar<typename CwiseUnaryOp<internal::scalar_multiple_op<Real>, DerType>::Type >(
268//         m_value * other,
269//         (m_derivatives * other));
270//     }
271//
272//     friend inline const AutoDiffScalar<typename CwiseUnaryOp<internal::scalar_multiple_op<Real>, DerType>::Type >
273//     operator*(const Real& other, const AutoDiffScalar& a)
274//     {
275//       return AutoDiffScalar<typename CwiseUnaryOp<internal::scalar_multiple_op<Real>, DerType>::Type >(
276//         a.value() * other,
277//         a.derivatives() * other);
278//     }
279
280    inline const AutoDiffScalar<CwiseUnaryOp<internal::scalar_multiple_op<Scalar>, const DerType> >
281    operator/(const Scalar& other) const
282    {
283      return AutoDiffScalar<CwiseUnaryOp<internal::scalar_multiple_op<Scalar>, const DerType> >(
284        m_value / other,
285        (m_derivatives * (Scalar(1)/other)));
286    }
287
288    friend inline const AutoDiffScalar<CwiseUnaryOp<internal::scalar_multiple_op<Scalar>, const DerType> >
289    operator/(const Scalar& other, const AutoDiffScalar& a)
290    {
291      return AutoDiffScalar<CwiseUnaryOp<internal::scalar_multiple_op<Scalar>, const DerType> >(
292        other / a.value(),
293        a.derivatives() * (Scalar(-other) / (a.value()*a.value())));
294    }
295
296//     inline const AutoDiffScalar<typename CwiseUnaryOp<internal::scalar_multiple_op<Real>, DerType>::Type >
297//     operator/(const Real& other) const
298//     {
299//       return AutoDiffScalar<typename CwiseUnaryOp<internal::scalar_multiple_op<Real>, DerType>::Type >(
300//         m_value / other,
301//         (m_derivatives * (Real(1)/other)));
302//     }
303//
304//     friend inline const AutoDiffScalar<typename CwiseUnaryOp<internal::scalar_multiple_op<Real>, DerType>::Type >
305//     operator/(const Real& other, const AutoDiffScalar& a)
306//     {
307//       return AutoDiffScalar<typename CwiseUnaryOp<internal::scalar_multiple_op<Real>, DerType>::Type >(
308//         other / a.value(),
309//         a.derivatives() * (-Real(1)/other));
310//     }
311
312    template<typename OtherDerType>
313    inline const AutoDiffScalar<CwiseUnaryOp<internal::scalar_multiple_op<Scalar>,
314        const CwiseBinaryOp<internal::scalar_difference_op<Scalar>,
315          const CwiseUnaryOp<internal::scalar_multiple_op<Scalar>, const DerType>,
316          const CwiseUnaryOp<internal::scalar_multiple_op<Scalar>, const typename internal::remove_all<OtherDerType>::type > > > >
317    operator/(const AutoDiffScalar<OtherDerType>& other) const
318    {
319      internal::make_coherent(m_derivatives, other.derivatives());
320      return AutoDiffScalar<CwiseUnaryOp<internal::scalar_multiple_op<Scalar>,
321        const CwiseBinaryOp<internal::scalar_difference_op<Scalar>,
322          const CwiseUnaryOp<internal::scalar_multiple_op<Scalar>, const DerType>,
323          const CwiseUnaryOp<internal::scalar_multiple_op<Scalar>, const typename internal::remove_all<OtherDerType>::type > > > >(
324        m_value / other.value(),
325          ((m_derivatives * other.value()) - (m_value * other.derivatives()))
326        * (Scalar(1)/(other.value()*other.value())));
327    }
328
329    template<typename OtherDerType>
330    inline const AutoDiffScalar<CwiseBinaryOp<internal::scalar_sum_op<Scalar>,
331        const CwiseUnaryOp<internal::scalar_multiple_op<Scalar>, const DerType>,
332        const CwiseUnaryOp<internal::scalar_multiple_op<Scalar>, const typename internal::remove_all<OtherDerType>::type> > >
333    operator*(const AutoDiffScalar<OtherDerType>& other) const
334    {
335      internal::make_coherent(m_derivatives, other.derivatives());
336      return AutoDiffScalar<const CwiseBinaryOp<internal::scalar_sum_op<Scalar>,
337        const CwiseUnaryOp<internal::scalar_multiple_op<Scalar>, const DerType>,
338        const CwiseUnaryOp<internal::scalar_multiple_op<Scalar>, const typename internal::remove_all<OtherDerType>::type > > >(
339        m_value * other.value(),
340        (m_derivatives * other.value()) + (m_value * other.derivatives()));
341    }
342
343    inline AutoDiffScalar& operator*=(const Scalar& other)
344    {
345      *this = *this * other;
346      return *this;
347    }
348
349    template<typename OtherDerType>
350    inline AutoDiffScalar& operator*=(const AutoDiffScalar<OtherDerType>& other)
351    {
352      *this = *this * other;
353      return *this;
354    }
355
356    inline AutoDiffScalar& operator/=(const Scalar& other)
357    {
358      *this = *this / other;
359      return *this;
360    }
361
362    template<typename OtherDerType>
363    inline AutoDiffScalar& operator/=(const AutoDiffScalar<OtherDerType>& other)
364    {
365      *this = *this / other;
366      return *this;
367    }
368
369  protected:
370    Scalar m_value;
371    DerType m_derivatives;
372
373};
374
375namespace internal {
376
377template<typename _DerType>
378struct auto_diff_special_op<_DerType, true>
379//   : auto_diff_scalar_op<_DerType, typename NumTraits<Scalar>::Real,
380//                            is_same<Scalar,typename NumTraits<Scalar>::Real>::value>
381{
382  typedef typename remove_all<_DerType>::type DerType;
383  typedef typename traits<DerType>::Scalar Scalar;
384  typedef typename NumTraits<Scalar>::Real Real;
385
386//   typedef auto_diff_scalar_op<_DerType, typename NumTraits<Scalar>::Real,
387//                            is_same<Scalar,typename NumTraits<Scalar>::Real>::value> Base;
388
389//   using Base::operator+;
390//   using Base::operator+=;
391//   using Base::operator-;
392//   using Base::operator-=;
393//   using Base::operator*;
394//   using Base::operator*=;
395
396  const AutoDiffScalar<_DerType>& derived() const { return *static_cast<const AutoDiffScalar<_DerType>*>(this); }
397  AutoDiffScalar<_DerType>& derived() { return *static_cast<AutoDiffScalar<_DerType>*>(this); }
398
399
400  inline const AutoDiffScalar<DerType&> operator+(const Real& other) const
401  {
402    return AutoDiffScalar<DerType&>(derived().value() + other, derived().derivatives());
403  }
404
405  friend inline const AutoDiffScalar<DerType&> operator+(const Real& a, const AutoDiffScalar<_DerType>& b)
406  {
407    return AutoDiffScalar<DerType&>(a + b.value(), b.derivatives());
408  }
409
410  inline AutoDiffScalar<_DerType>& operator+=(const Real& other)
411  {
412    derived().value() += other;
413    return derived();
414  }
415
416
417  inline const AutoDiffScalar<typename CwiseUnaryOp<scalar_multiple2_op<Scalar,Real>, DerType>::Type >
418  operator*(const Real& other) const
419  {
420    return AutoDiffScalar<typename CwiseUnaryOp<scalar_multiple2_op<Scalar,Real>, DerType>::Type >(
421      derived().value() * other,
422      derived().derivatives() * other);
423  }
424
425  friend inline const AutoDiffScalar<typename CwiseUnaryOp<scalar_multiple2_op<Scalar,Real>, DerType>::Type >
426  operator*(const Real& other, const AutoDiffScalar<_DerType>& a)
427  {
428    return AutoDiffScalar<typename CwiseUnaryOp<scalar_multiple2_op<Scalar,Real>, DerType>::Type >(
429      a.value() * other,
430      a.derivatives() * other);
431  }
432
433  inline AutoDiffScalar<_DerType>& operator*=(const Scalar& other)
434  {
435    *this = *this * other;
436    return derived();
437  }
438};
439
440template<typename _DerType>
441struct auto_diff_special_op<_DerType, false>
442{
443  void operator*() const;
444  void operator-() const;
445  void operator+() const;
446};
447
448template<typename A_Scalar, int A_Rows, int A_Cols, int A_Options, int A_MaxRows, int A_MaxCols, typename B>
449struct make_coherent_impl<Matrix<A_Scalar, A_Rows, A_Cols, A_Options, A_MaxRows, A_MaxCols>, B> {
450  typedef Matrix<A_Scalar, A_Rows, A_Cols, A_Options, A_MaxRows, A_MaxCols> A;
451  static void run(A& a, B& b) {
452    if((A_Rows==Dynamic || A_Cols==Dynamic) && (a.size()==0))
453    {
454      a.resize(b.size());
455      a.setZero();
456    }
457  }
458};
459
460template<typename A, typename B_Scalar, int B_Rows, int B_Cols, int B_Options, int B_MaxRows, int B_MaxCols>
461struct make_coherent_impl<A, Matrix<B_Scalar, B_Rows, B_Cols, B_Options, B_MaxRows, B_MaxCols> > {
462  typedef Matrix<B_Scalar, B_Rows, B_Cols, B_Options, B_MaxRows, B_MaxCols> B;
463  static void run(A& a, B& b) {
464    if((B_Rows==Dynamic || B_Cols==Dynamic) && (b.size()==0))
465    {
466      b.resize(a.size());
467      b.setZero();
468    }
469  }
470};
471
472template<typename A_Scalar, int A_Rows, int A_Cols, int A_Options, int A_MaxRows, int A_MaxCols,
473         typename B_Scalar, int B_Rows, int B_Cols, int B_Options, int B_MaxRows, int B_MaxCols>
474struct make_coherent_impl<Matrix<A_Scalar, A_Rows, A_Cols, A_Options, A_MaxRows, A_MaxCols>,
475                             Matrix<B_Scalar, B_Rows, B_Cols, B_Options, B_MaxRows, B_MaxCols> > {
476  typedef Matrix<A_Scalar, A_Rows, A_Cols, A_Options, A_MaxRows, A_MaxCols> A;
477  typedef Matrix<B_Scalar, B_Rows, B_Cols, B_Options, B_MaxRows, B_MaxCols> B;
478  static void run(A& a, B& b) {
479    if((A_Rows==Dynamic || A_Cols==Dynamic) && (a.size()==0))
480    {
481      a.resize(b.size());
482      a.setZero();
483    }
484    else if((B_Rows==Dynamic || B_Cols==Dynamic) && (b.size()==0))
485    {
486      b.resize(a.size());
487      b.setZero();
488    }
489  }
490};
491
492template<typename A_Scalar, int A_Rows, int A_Cols, int A_Options, int A_MaxRows, int A_MaxCols>
493struct scalar_product_traits<Matrix<A_Scalar, A_Rows, A_Cols, A_Options, A_MaxRows, A_MaxCols>,A_Scalar>
494{
495  enum { Defined = 1 };
496  typedef Matrix<A_Scalar, A_Rows, A_Cols, A_Options, A_MaxRows, A_MaxCols> ReturnType;
497};
498
499template<typename A_Scalar, int A_Rows, int A_Cols, int A_Options, int A_MaxRows, int A_MaxCols>
500struct scalar_product_traits<A_Scalar, Matrix<A_Scalar, A_Rows, A_Cols, A_Options, A_MaxRows, A_MaxCols> >
501{
502  enum { Defined = 1 };
503  typedef Matrix<A_Scalar, A_Rows, A_Cols, A_Options, A_MaxRows, A_MaxCols> ReturnType;
504};
505
506template<typename DerType>
507struct scalar_product_traits<AutoDiffScalar<DerType>,typename DerType::Scalar>
508{
509  enum { Defined = 1 };
510  typedef AutoDiffScalar<DerType> ReturnType;
511};
512
513template<typename DerType>
514struct scalar_product_traits<typename DerType::Scalar,AutoDiffScalar<DerType> >
515{
516  enum { Defined = 1 };
517  typedef AutoDiffScalar<DerType> ReturnType;
518};
519
520} // end namespace internal
521
522#define EIGEN_AUTODIFF_DECLARE_GLOBAL_UNARY(FUNC,CODE) \
523  template<typename DerType> \
524  inline const Eigen::AutoDiffScalar<Eigen::CwiseUnaryOp<Eigen::internal::scalar_multiple_op<typename Eigen::internal::traits<typename Eigen::internal::remove_all<DerType>::type>::Scalar>, const typename Eigen::internal::remove_all<DerType>::type> > \
525  FUNC(const Eigen::AutoDiffScalar<DerType>& x) { \
526    using namespace Eigen; \
527    typedef typename Eigen::internal::traits<typename Eigen::internal::remove_all<DerType>::type>::Scalar Scalar; \
528    typedef AutoDiffScalar<CwiseUnaryOp<Eigen::internal::scalar_multiple_op<Scalar>, const typename Eigen::internal::remove_all<DerType>::type> > ReturnType; \
529    CODE; \
530  }
531
532template<typename DerType>
533inline const AutoDiffScalar<DerType>& conj(const AutoDiffScalar<DerType>& x)  { return x; }
534template<typename DerType>
535inline const AutoDiffScalar<DerType>& real(const AutoDiffScalar<DerType>& x)  { return x; }
536template<typename DerType>
537inline typename DerType::Scalar imag(const AutoDiffScalar<DerType>&)    { return 0.; }
538template<typename DerType, typename T>
539inline AutoDiffScalar<DerType> (min)(const AutoDiffScalar<DerType>& x, const T& y)    { return (x <= y ? x : y); }
540template<typename DerType, typename T>
541inline AutoDiffScalar<DerType> (max)(const AutoDiffScalar<DerType>& x, const T& y)    { return (x >= y ? x : y); }
542template<typename DerType, typename T>
543inline AutoDiffScalar<DerType> (min)(const T& x, const AutoDiffScalar<DerType>& y)    { return (x < y ? x : y); }
544template<typename DerType, typename T>
545inline AutoDiffScalar<DerType> (max)(const T& x, const AutoDiffScalar<DerType>& y)    { return (x > y ? x : y); }
546
547EIGEN_AUTODIFF_DECLARE_GLOBAL_UNARY(abs,
548  using std::abs;
549  return ReturnType(abs(x.value()), x.derivatives() * (x.value()<0 ? -1 : 1) );)
550
551EIGEN_AUTODIFF_DECLARE_GLOBAL_UNARY(abs2,
552  using numext::abs2;
553  return ReturnType(abs2(x.value()), x.derivatives() * (Scalar(2)*x.value()));)
554
555EIGEN_AUTODIFF_DECLARE_GLOBAL_UNARY(sqrt,
556  using std::sqrt;
557  Scalar sqrtx = sqrt(x.value());
558  return ReturnType(sqrtx,x.derivatives() * (Scalar(0.5) / sqrtx));)
559
560EIGEN_AUTODIFF_DECLARE_GLOBAL_UNARY(cos,
561  using std::cos;
562  using std::sin;
563  return ReturnType(cos(x.value()), x.derivatives() * (-sin(x.value())));)
564
565EIGEN_AUTODIFF_DECLARE_GLOBAL_UNARY(sin,
566  using std::sin;
567  using std::cos;
568  return ReturnType(sin(x.value()),x.derivatives() * cos(x.value()));)
569
570EIGEN_AUTODIFF_DECLARE_GLOBAL_UNARY(exp,
571  using std::exp;
572  Scalar expx = exp(x.value());
573  return ReturnType(expx,x.derivatives() * expx);)
574
575EIGEN_AUTODIFF_DECLARE_GLOBAL_UNARY(log,
576  using std::log;
577  return ReturnType(log(x.value()),x.derivatives() * (Scalar(1)/x.value()));)
578
579template<typename DerType>
580inline const Eigen::AutoDiffScalar<Eigen::CwiseUnaryOp<Eigen::internal::scalar_multiple_op<typename Eigen::internal::traits<DerType>::Scalar>, const DerType> >
581pow(const Eigen::AutoDiffScalar<DerType>& x, typename Eigen::internal::traits<DerType>::Scalar y)
582{
583  using namespace Eigen;
584  typedef typename Eigen::internal::traits<DerType>::Scalar Scalar;
585  return AutoDiffScalar<CwiseUnaryOp<Eigen::internal::scalar_multiple_op<Scalar>, const DerType> >(
586    std::pow(x.value(),y),
587    x.derivatives() * (y * std::pow(x.value(),y-1)));
588}
589
590
591template<typename DerTypeA,typename DerTypeB>
592inline const AutoDiffScalar<Matrix<typename internal::traits<DerTypeA>::Scalar,Dynamic,1> >
593atan2(const AutoDiffScalar<DerTypeA>& a, const AutoDiffScalar<DerTypeB>& b)
594{
595  using std::atan2;
596  using std::max;
597  typedef typename internal::traits<DerTypeA>::Scalar Scalar;
598  typedef AutoDiffScalar<Matrix<Scalar,Dynamic,1> > PlainADS;
599  PlainADS ret;
600  ret.value() = atan2(a.value(), b.value());
601
602  Scalar tmp2 = a.value() * a.value();
603  Scalar tmp3 = b.value() * b.value();
604  Scalar tmp4 = tmp3/(tmp2+tmp3);
605
606  if (tmp4!=0)
607    ret.derivatives() = (a.derivatives() * b.value() - a.value() * b.derivatives()) * (tmp2+tmp3);
608
609  return ret;
610}
611
612EIGEN_AUTODIFF_DECLARE_GLOBAL_UNARY(tan,
613  using std::tan;
614  using std::cos;
615  return ReturnType(tan(x.value()),x.derivatives() * (Scalar(1)/numext::abs2(cos(x.value()))));)
616
617EIGEN_AUTODIFF_DECLARE_GLOBAL_UNARY(asin,
618  using std::sqrt;
619  using std::asin;
620  return ReturnType(asin(x.value()),x.derivatives() * (Scalar(1)/sqrt(1-numext::abs2(x.value()))));)
621
622EIGEN_AUTODIFF_DECLARE_GLOBAL_UNARY(acos,
623  using std::sqrt;
624  using std::acos;
625  return ReturnType(acos(x.value()),x.derivatives() * (Scalar(-1)/sqrt(1-numext::abs2(x.value()))));)
626
627#undef EIGEN_AUTODIFF_DECLARE_GLOBAL_UNARY
628
629template<typename DerType> struct NumTraits<AutoDiffScalar<DerType> >
630  : NumTraits< typename NumTraits<typename DerType::Scalar>::Real >
631{
632  typedef AutoDiffScalar<Matrix<typename NumTraits<typename DerType::Scalar>::Real,DerType::RowsAtCompileTime,DerType::ColsAtCompileTime> > Real;
633  typedef AutoDiffScalar<DerType> NonInteger;
634  typedef AutoDiffScalar<DerType>& Nested;
635  enum{
636    RequireInitialization = 1
637  };
638};
639
640}
641
642#endif // EIGEN_AUTODIFF_SCALAR_H
643