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wolfvJohanMabille
wolfv
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JohanMabille
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add complex functions: arg, angle, conj, norm (xtensor-stack#280)
* add complex functions: arg, angle, conj, norm * add tests for complex functions, fix strided view layout interface * add numeric constants * add numeric_constants to xmath
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Lines changed: 170 additions & 2 deletions

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‎include/xtensor/xcomplex.hpp‎

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@@ -129,5 +129,87 @@ namespace xt
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{
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return detail::complex_expression_helper<is_xexpression<std::decay_t<E>>::value>::imag(std::forward<E>(e));
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}
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#define UNARY_COMPLEX_FUNCTOR(NAME)\
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template <class T>\
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struct NAME##_fun {\
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using argument_type = T;\
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using result_type = decltype(std::NAME(std::declval<T>()));\
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constexpr result_type operator()(const T& t) const {\
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using std::NAME;\
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return NAME(t);\
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}\
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}
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namespace math
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{
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UNARY_COMPLEX_FUNCTOR(conj);
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UNARY_COMPLEX_FUNCTOR(norm);
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UNARY_COMPLEX_FUNCTOR(arg);
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}
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#undef UNARY_COMPLEX_FUNCTOR
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/**
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* @brief Returns an \ref xfunction evaluating to the complex conjugate of the given expression.
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*
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* @param e the \ref xexpression
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*/
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template <class E>
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inline auto conj(E&& e) noexcept
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{
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using value_type = typename std::decay_t<E>::value_type;
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using functor = math::conj_fun<value_type>;
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using result_type = typename functor::result_type;
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using type = xfunction<functor, result_type, const_xclosure_t<E>>;
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return type(functor(), std::forward<E>(e));
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}
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/**
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* @brief Calculates the phase angle (in radians) elementwise for the complex numbers in e.
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* @param e the \ref xexpression
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*/
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template <class E>
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inline auto arg(E&& e) noexcept
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{
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using value_type = typename std::decay_t<E>::value_type;
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using functor = math::arg_fun<value_type>;
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using result_type = typename functor::result_type;
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using type = xfunction<functor, result_type, const_xclosure_t<E>>;
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return type(functor(), std::forward<E>(e));
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}
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/**
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* @brief Calculates the phase angle elementwise for the complex numbers in e.
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* Note that this function might be slightly less perfomant than \ref arg.
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* @param e the \ref xexpression
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* @param deg calculate angle in degrees instead of radians
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*/
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template <class E>
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inline auto angle(E&& e, bool deg = false) noexcept
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{
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using value_type = complex_value_type_t<typename std::decay_t<E>::value_type>;
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value_type multiplier = 1.0;
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if (deg)
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{
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multiplier = value_type(180) / numeric_constants<value_type>::PI;
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}
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return arg(std::forward<E>(e)) * std::move(multiplier);
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}
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/**
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* Calculates the squared magnitude elementwise for the complex numbers in e.
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* Equivalent to pow(real(e), 2) + pow(imag(e), 2).
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* @param e the \ref xexpression
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*/
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template <class E>
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inline auto norm(E&& e) noexcept
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{
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using value_type = typename std::decay_t<E>::value_type;
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using functor = math::norm_fun<value_type>;
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using result_type = typename functor::result_type;
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using type = xfunction<functor, result_type, const_xclosure_t<E>>;
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return type(functor(), std::forward<E>(e));
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}
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}
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#endif

‎include/xtensor/xmath.hpp‎

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@@ -22,6 +22,22 @@
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namespace xt
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{
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template <class T>
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struct numeric_constants
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{
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static constexpr T PI = 3.141592653589793238463;
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static constexpr T PI_2 = 1.57079632679489661923;
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static constexpr T PI_4 = 0.785398163397448309616;
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static constexpr T D_1_PI = 0.318309886183790671538;
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static constexpr T D_2_PI = 0.636619772367581343076;
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static constexpr T D_2_SQRTPI = 1.12837916709551257390;
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static constexpr T SQRT2 = 1.41421356237309504880;
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static constexpr T SQRT1_2 = 0.707106781186547524401;
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static constexpr T E = 2.71828182845904523536;
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static constexpr T LOG2E = 1.44269504088896340736;
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static constexpr T LOG10E = 0.434294481903251827651;
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static constexpr T LN2 = 0.693147180559945309417;
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};
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/***********
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* Helpers *
@@ -46,6 +62,17 @@ namespace xt
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}\
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}
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#define UNARY_MATH_FUNCTOR_COMPLEX_REDUCING(NAME)\
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template <class T>\
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struct NAME##_fun {\
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using argument_type = T;\
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using result_type = complex_value_type_t<T>;\
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constexpr result_type operator()(const T& arg) const {\
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using std::NAME;\
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return NAME(arg);\
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}\
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}
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#define BINARY_MATH_FUNCTOR(NAME)\
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template <class T>\
5178
struct NAME##_fun {\
@@ -84,7 +111,7 @@ namespace xt
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namespace math
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{
87-
UNARY_MATH_FUNCTOR(abs);
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UNARY_MATH_FUNCTOR_COMPLEX_REDUCING(abs);
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UNARY_MATH_FUNCTOR(fabs);
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BINARY_MATH_FUNCTOR(fmod);
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BINARY_MATH_FUNCTOR(remainder);
@@ -129,6 +156,7 @@ namespace xt
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#undef TERNARY_MATH_FUNCTOR
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#undef BINARY_MATH_FUNCTOR
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#undef UNARY_MATH_FUNCTOR
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#undef UNARY_MATH_FUNCTOR_COMPLEX_REDUCING
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/*******************
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* basic functions *

‎include/xtensor/xstridedview.hpp‎

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@@ -120,6 +120,7 @@ namespace xt
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const shape_type& shape() const noexcept;
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const strides_type& strides() const noexcept;
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const backstrides_type& backstrides() const noexcept;
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layout_type layout() const noexcept;
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reference operator()();
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template <class... Args>
@@ -281,6 +282,12 @@ namespace xt
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return m_backstrides;
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}
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template <class CT, class S, class CD>
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inline auto xstrided_view<CT, S, CD>::layout() const noexcept -> layout_type
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{
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return layout_type::row_major;
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}
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template <class CT, class S, class CD>
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inline auto xstrided_view<CT, S, CD>::data() noexcept -> underlying_container_type&
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{

‎include/xtensor/xutils.hpp‎

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@@ -768,6 +768,25 @@ namespace xt
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static constexpr bool value = detail::is_complex<std::decay_t<T>>::value;
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};
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/*************************************
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* complex_value_type implementation *
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*************************************/
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template <typename T>
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struct complex_value_type
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{
778+
using type = T;
779+
};
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template <typename T>
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struct complex_value_type<std::complex<T>>
783+
{
784+
using type = T;
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};
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787+
template <class T>
788+
using complex_value_type_t = typename complex_value_type<T>::type;
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/*********************************
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* forward_offset implementation *
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*********************************/

‎test/test_xcomplex.cpp‎

Lines changed: 33 additions & 1 deletion
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@@ -103,5 +103,37 @@ namespace xt
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auto it = r.begin();
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EXPECT_EQ(*(it.operator->()), 1.0);
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}
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}
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107+
TEST(xcomplex, abs_angle_conj)
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{
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xarray<std::complex<double>> cmplarg_0 = {{ 0.40101756+0.71233018i, 0.62731701+0.42786349i, 0.32415089+0.2977805i },
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{ 0.24475928+0.49208478i, 0.69475518+0.74029639i, 0.59390240+0.35772892i},
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{ 0.63179202+0.41720995i, 0.44025718+0.65472131i, 0.08372648+0.37380143i}};
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auto cmplres = xt::abs(cmplarg_0);
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xarray<double> cmplexpected = {{ 0.81745298, 0.75933774, 0.44016704},
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{ 0.54959488, 1.01524554, 0.69331814},
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{ 0.75711643, 0.78897806, 0.38306348}};
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EXPECT_TRUE(allclose(cmplexpected, cmplres));
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auto cmplres_angle = xt::angle(cmplarg_0);
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xarray<double> cmplexpected_angle = {{ 1.05805307, 0.59857922, 0.74302273},
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{ 1.10923689, 0.81712241, 0.54213553},
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{ 0.58362348, 0.97881125, 1.35044673}};
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EXPECT_TRUE(allclose(cmplexpected_angle, cmplres_angle));
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auto cmplres_conj = xt::conj(cmplarg_0);
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xarray<std::complex<double>> cmplexpected_conj = {{ 0.40101756-0.71233018i, 0.62731701-0.42786349i, 0.32415089-0.2977805i },
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{ 0.24475928-0.49208478i, 0.69475518-0.74029639i, 0.59390240-0.35772892i},
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{ 0.63179202-0.41720995i, 0.44025718-0.65472131i, 0.08372648-0.37380143i}};
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EXPECT_TRUE(allclose(imag(cmplexpected_conj), imag(cmplres_conj)));
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EXPECT_TRUE(allclose(real(cmplexpected_conj), real(cmplres_conj)));
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auto cmplres_norm = xt::norm(cmplarg_0);
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xarray<double> fieldnorm = {{ 0.66822937, 0.5765938 , 0.19374703},
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{ 0.30205453, 1.0307235 , 0.48069004},
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{ 0.57322529, 0.62248637, 0.14673763}};
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EXPECT_TRUE(allclose(fieldnorm, cmplres_norm));
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}
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}

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