diff options
Diffstat (limited to 'Eigen/src/Core/MathFunctions.h')
| -rw-r--r-- | Eigen/src/Core/MathFunctions.h | 78 |
1 files changed, 45 insertions, 33 deletions
diff --git a/Eigen/src/Core/MathFunctions.h b/Eigen/src/Core/MathFunctions.h index e9fed2e52..16ad2dc7e 100644 --- a/Eigen/src/Core/MathFunctions.h +++ b/Eigen/src/Core/MathFunctions.h @@ -14,7 +14,7 @@ namespace Eigen { // On WINCE, std::abs is defined for int only, so let's defined our own overloads: // This issue has been confirmed with MSVC 2008 only, but the issue might exist for more recent versions too. -#if defined(_WIN32_WCE) && defined(_MSC_VER) && _MSC_VER<=1500 +#if EIGEN_OS_WINCE && EIGEN_COMP_MSVC && EIGEN_COMP_MSVC<=1500 long abs(long x) { return (labs(x)); } double abs(double x) { return (fabs(x)); } float abs(float x) { return (fabsf(x)); } @@ -360,50 +360,31 @@ inline NewType cast(const OldType& x) } /**************************************************************************** -* Implementation of atanh2 * +* Implementation of logp1 * ****************************************************************************/ template<typename Scalar> -struct atanh2_impl +struct log1p_impl { - static inline Scalar run(const Scalar& x, const Scalar& r) + static inline Scalar run(const Scalar& x) { EIGEN_STATIC_ASSERT_NON_INTEGER(Scalar) - #if (__cplusplus >= 201103L) && !defined(__CYGWIN__) + // Let's be conservative and enable the default C++11 implementation only if we are sure it exists + #if (__cplusplus >= 201103L) && (EIGEN_COMP_GNUC_STRICT || EIGEN_COMP_CLANG || EIGEN_COMP_MSVC || EIGEN_COMP_ICC) \ + && (EIGEN_ARCH_i386_OR_x86_64) && (EIGEN_OS_GNULINUX || EIGEN_OS_WIN_STRICT || EIGEN_OS_MAC) using std::log1p; - return log1p(2 * x / (r - x)) / 2; + return log1p(x); #else - using std::abs; + typedef typename NumTraits<Scalar>::Real RealScalar; using std::log; - using std::sqrt; - Scalar z = x / r; - if (r == 0 || abs(z) > sqrt(NumTraits<Scalar>::epsilon())) - return log((r + x) / (r - x)) / 2; - else - return z + z*z*z / 3; + Scalar x1p = RealScalar(1) + x; + return ( x1p == Scalar(1) ) ? x : x * ( log(x1p) / (x1p - RealScalar(1)) ); #endif } }; -template<typename RealScalar> -struct atanh2_impl<std::complex<RealScalar> > -{ - typedef std::complex<RealScalar> Scalar; - static inline Scalar run(const Scalar& x, const Scalar& r) - { - using std::log; - using std::norm; - using std::sqrt; - Scalar z = x / r; - if (r == Scalar(0) || norm(z) > NumTraits<RealScalar>::epsilon()) - return RealScalar(0.5) * log((r + x) / (r - x)); - else - return z + z*z*z / RealScalar(3); - } -}; - template<typename Scalar> -struct atanh2_retval +struct log1p_retval { typedef Scalar type; }; @@ -591,6 +572,22 @@ inline EIGEN_MATHFUNC_RETVAL(random, Scalar) random() ****************************************************************************/ namespace numext { + +template<typename T> +EIGEN_DEVICE_FUNC +inline T mini(const T& x, const T& y) +{ + EIGEN_USING_STD_MATH(min); + return min EIGEN_NOT_A_MACRO (x,y); +} + +template<typename T> +EIGEN_DEVICE_FUNC +inline T maxi(const T& x, const T& y) +{ + EIGEN_USING_STD_MATH(max); + return max EIGEN_NOT_A_MACRO (x,y); +} template<typename Scalar> EIGEN_DEVICE_FUNC @@ -664,9 +661,9 @@ inline EIGEN_MATHFUNC_RETVAL(hypot, Scalar) hypot(const Scalar& x, const Scalar& template<typename Scalar> EIGEN_DEVICE_FUNC -inline EIGEN_MATHFUNC_RETVAL(atanh2, Scalar) atanh2(const Scalar& x, const Scalar& y) +inline EIGEN_MATHFUNC_RETVAL(log1p, Scalar) log1p(const Scalar& x) { - return EIGEN_MATHFUNC_IMPL(atanh2, Scalar)::run(x, y); + return EIGEN_MATHFUNC_IMPL(log1p, Scalar)::run(x); } template<typename Scalar> @@ -694,6 +691,21 @@ bool (isfinite)(const std::complex<T>& x) return isfinite(real(x)) && isfinite(imag(x)); } +// Log base 2 for 32 bits positive integers. +// Conveniently returns 0 for x==0. +inline int log2(int x) +{ + eigen_assert(x>=0); + unsigned int v(x); + static const int table[32] = { 0, 9, 1, 10, 13, 21, 2, 29, 11, 14, 16, 18, 22, 25, 3, 30, 8, 12, 20, 28, 15, 17, 24, 7, 19, 27, 23, 6, 26, 5, 4, 31 }; + v |= v >> 1; + v |= v >> 2; + v |= v >> 4; + v |= v >> 8; + v |= v >> 16; + return table[(v * 0x07C4ACDDU) >> 27]; +} + } // end namespace numext namespace internal { |