diff options
Diffstat (limited to 'Eigen/src/Core/NumTraits.h')
| -rw-r--r-- | Eigen/src/Core/NumTraits.h | 136 |
1 files changed, 116 insertions, 20 deletions
diff --git a/Eigen/src/Core/NumTraits.h b/Eigen/src/Core/NumTraits.h index bac9e50b8..dd61195bc 100644 --- a/Eigen/src/Core/NumTraits.h +++ b/Eigen/src/Core/NumTraits.h @@ -12,24 +12,57 @@ namespace Eigen { +namespace internal { + +// default implementation of digits10(), based on numeric_limits if specialized, +// 0 for integer types, and log10(epsilon()) otherwise. +template< typename T, + bool use_numeric_limits = std::numeric_limits<T>::is_specialized, + bool is_integer = NumTraits<T>::IsInteger> +struct default_digits10_impl +{ + static int run() { return std::numeric_limits<T>::digits10; } +}; + +template<typename T> +struct default_digits10_impl<T,false,false> // Floating point +{ + static int run() { + using std::log10; + using std::ceil; + typedef typename NumTraits<T>::Real Real; + return int(ceil(-log10(NumTraits<Real>::epsilon()))); + } +}; + +template<typename T> +struct default_digits10_impl<T,false,true> // Integer +{ + static int run() { return 0; } +}; + +} // end namespace internal + /** \class NumTraits * \ingroup Core_Module * * \brief Holds information about the various numeric (i.e. scalar) types allowed by Eigen. * - * \param T the numeric type at hand + * \tparam T the numeric type at hand * * This class stores enums, typedefs and static methods giving information about a numeric type. * * The provided data consists of: - * \li A typedef \a Real, giving the "real part" type of \a T. If \a T is already real, - * then \a Real is just a typedef to \a T. If \a T is \c std::complex<U> then \a Real + * \li A typedef \c Real, giving the "real part" type of \a T. If \a T is already real, + * then \c Real is just a typedef to \a T. If \a T is \c std::complex<U> then \c Real * is a typedef to \a U. - * \li A typedef \a NonInteger, giving the type that should be used for operations producing non-integral values, + * \li A typedef \c NonInteger, giving the type that should be used for operations producing non-integral values, * such as quotients, square roots, etc. If \a T is a floating-point type, then this typedef just gives * \a T again. Note however that many Eigen functions such as internal::sqrt simply refuse to * take integers. Outside of a few cases, Eigen doesn't do automatic type promotion. Thus, this typedef is * only intended as a helper for code that needs to explicitly promote types. + * \li A typedef \c Literal giving the type to use for numeric literals such as "2" or "0.5". For instance, for \c std::complex<U>, Literal is defined as \c U. + * Of course, this type must be fully compatible with \a T. In doubt, just use \a T here. * \li A typedef \a Nested giving the type to use to nest a value inside of the expression tree. If you don't know what * this means, just use \a T here. * \li An enum value \a IsComplex. It is equal to 1 if \a T is a \c std::complex @@ -42,10 +75,14 @@ namespace Eigen { * \li An enum value \a IsSigned. It is equal to \c 1 if \a T is a signed type and to 0 if \a T is unsigned. * \li An enum value \a RequireInitialization. It is equal to \c 1 if the constructor of the numeric type \a T must * be called, and to 0 if it is safe not to call it. Default is 0 if \a T is an arithmetic type, and 1 otherwise. - * \li An epsilon() function which, unlike std::numeric_limits::epsilon(), returns a \a Real instead of a \a T. + * \li An epsilon() function which, unlike <a href="http://en.cppreference.com/w/cpp/types/numeric_limits/epsilon">std::numeric_limits::epsilon()</a>, + * it returns a \a Real instead of a \a T. * \li A dummy_precision() function returning a weak epsilon value. It is mainly used as a default * value by the fuzzy comparison operators. * \li highest() and lowest() functions returning the highest and lowest possible values respectively. + * \li digits10() function returning the number of decimal digits that can be represented without change. This is + * the analogue of <a href="http://en.cppreference.com/w/cpp/types/numeric_limits/digits10">std::numeric_limits<T>::digits10</a> + * which is used as the default implementation if specialized. */ template<typename T> struct GenericNumTraits @@ -67,22 +104,47 @@ template<typename T> struct GenericNumTraits T >::type NonInteger; typedef T Nested; + typedef T Literal; + + EIGEN_DEVICE_FUNC + static inline Real epsilon() + { + return numext::numeric_limits<T>::epsilon(); + } - static inline Real epsilon() { return std::numeric_limits<T>::epsilon(); } + EIGEN_DEVICE_FUNC + static inline int digits10() + { + return internal::default_digits10_impl<T>::run(); + } + + EIGEN_DEVICE_FUNC static inline Real dummy_precision() { // make sure to override this for floating-point types return Real(0); } - static inline T highest() { return (std::numeric_limits<T>::max)(); } - static inline T lowest() { return IsInteger ? (std::numeric_limits<T>::min)() : (-(std::numeric_limits<T>::max)()); } - -#ifdef EIGEN2_SUPPORT - enum { - HasFloatingPoint = !IsInteger - }; - typedef NonInteger FloatingPoint; -#endif + + + EIGEN_DEVICE_FUNC + static inline T highest() { + return (numext::numeric_limits<T>::max)(); + } + + EIGEN_DEVICE_FUNC + static inline T lowest() { + return IsInteger ? (numext::numeric_limits<T>::min)() : (-(numext::numeric_limits<T>::max)()); + } + + EIGEN_DEVICE_FUNC + static inline T infinity() { + return numext::numeric_limits<T>::infinity(); + } + + EIGEN_DEVICE_FUNC + static inline T quiet_NaN() { + return numext::numeric_limits<T>::quiet_NaN(); + } }; template<typename T> struct NumTraits : GenericNumTraits<T> @@ -91,11 +153,13 @@ template<typename T> struct NumTraits : GenericNumTraits<T> template<> struct NumTraits<float> : GenericNumTraits<float> { + EIGEN_DEVICE_FUNC static inline float dummy_precision() { return 1e-5f; } }; template<> struct NumTraits<double> : GenericNumTraits<double> { + EIGEN_DEVICE_FUNC static inline double dummy_precision() { return 1e-12; } }; @@ -109,6 +173,7 @@ template<typename _Real> struct NumTraits<std::complex<_Real> > : GenericNumTraits<std::complex<_Real> > { typedef _Real Real; + typedef typename NumTraits<_Real>::Literal Literal; enum { IsComplex = 1, RequireInitialization = NumTraits<_Real>::RequireInitialization, @@ -117,8 +182,12 @@ template<typename _Real> struct NumTraits<std::complex<_Real> > MulCost = 4 * NumTraits<Real>::MulCost + 2 * NumTraits<Real>::AddCost }; + EIGEN_DEVICE_FUNC static inline Real epsilon() { return NumTraits<Real>::epsilon(); } + EIGEN_DEVICE_FUNC static inline Real dummy_precision() { return NumTraits<Real>::dummy_precision(); } + EIGEN_DEVICE_FUNC + static inline int digits10() { return NumTraits<Real>::digits10(); } }; template<typename Scalar, int Rows, int Cols, int Options, int MaxRows, int MaxCols> @@ -130,21 +199,48 @@ struct NumTraits<Array<Scalar, Rows, Cols, Options, MaxRows, MaxCols> > typedef typename NumTraits<Scalar>::NonInteger NonIntegerScalar; typedef Array<NonIntegerScalar, Rows, Cols, Options, MaxRows, MaxCols> NonInteger; typedef ArrayType & Nested; - + typedef typename NumTraits<Scalar>::Literal Literal; + enum { IsComplex = NumTraits<Scalar>::IsComplex, IsInteger = NumTraits<Scalar>::IsInteger, IsSigned = NumTraits<Scalar>::IsSigned, RequireInitialization = 1, - ReadCost = ArrayType::SizeAtCompileTime==Dynamic ? Dynamic : ArrayType::SizeAtCompileTime * NumTraits<Scalar>::ReadCost, - AddCost = ArrayType::SizeAtCompileTime==Dynamic ? Dynamic : ArrayType::SizeAtCompileTime * NumTraits<Scalar>::AddCost, - MulCost = ArrayType::SizeAtCompileTime==Dynamic ? Dynamic : ArrayType::SizeAtCompileTime * NumTraits<Scalar>::MulCost + ReadCost = ArrayType::SizeAtCompileTime==Dynamic ? HugeCost : ArrayType::SizeAtCompileTime * NumTraits<Scalar>::ReadCost, + AddCost = ArrayType::SizeAtCompileTime==Dynamic ? HugeCost : ArrayType::SizeAtCompileTime * NumTraits<Scalar>::AddCost, + MulCost = ArrayType::SizeAtCompileTime==Dynamic ? HugeCost : ArrayType::SizeAtCompileTime * NumTraits<Scalar>::MulCost }; - + + EIGEN_DEVICE_FUNC static inline RealScalar epsilon() { return NumTraits<RealScalar>::epsilon(); } + EIGEN_DEVICE_FUNC static inline RealScalar dummy_precision() { return NumTraits<RealScalar>::dummy_precision(); } }; +template<> struct NumTraits<std::string> + : GenericNumTraits<std::string> +{ + enum { + RequireInitialization = 1, + ReadCost = HugeCost, + AddCost = HugeCost, + MulCost = HugeCost + }; + + static inline int digits10() { return 0; } + +private: + static inline std::string epsilon(); + static inline std::string dummy_precision(); + static inline std::string lowest(); + static inline std::string highest(); + static inline std::string infinity(); + static inline std::string quiet_NaN(); +}; + +// Empty specialization for void to allow template specialization based on NumTraits<T>::Real with T==void and SFINAE. +template<> struct NumTraits<void> {}; + } // end namespace Eigen #endif // EIGEN_NUMTRAITS_H |