AK: Add complex number library

Useful for diverse algorithms.
Also added some tests for it.
This commit is contained in:
Cesar Torres 2021-03-19 22:23:48 +01:00 committed by Andreas Kling
parent 0d5e1e9df1
commit f4f5a1c0e7
4 changed files with 412 additions and 0 deletions

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AK/Complex.h Normal file
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/*
* Copyright (c) 2021, Cesar Torres <shortanemoia@protonmail.com>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#pragma once
#include <AK/Concepts.h>
#if __has_include(<math.h>)
# define AKCOMPLEX_CAN_USE_MATH_H
# include <math.h>
#endif
#ifdef __cplusplus
# if __cplusplus >= 201103L
# define COMPLEX_NOEXCEPT noexcept
# endif
namespace AK {
template<AK::Concepts::Arithmetic T>
class [[gnu::packed]] Complex {
public:
constexpr Complex()
: m_real(0)
, m_imag(0)
{
}
constexpr Complex(T real)
: m_real(real)
, m_imag((T)0)
{
}
constexpr Complex(T real, T imaginary)
: m_real(real)
, m_imag(imaginary)
{
}
constexpr T real() const COMPLEX_NOEXCEPT { return m_real; }
constexpr T imag() const COMPLEX_NOEXCEPT { return m_imag; }
constexpr T magnitude_squared() const COMPLEX_NOEXCEPT { return m_real * m_real + m_imag * m_imag; }
# ifdef AKCOMPLEX_CAN_USE_MATH_H
constexpr T magnitude() const COMPLEX_NOEXCEPT
{
// for numbers 32 or under bit long we don't need the extra precision of sqrt
// although it may return values with a considerable error if real and imag are too big?
if constexpr (sizeof(T) <= sizeof(float)) {
return sqrtf(m_real * m_real + m_imag * m_imag);
} else if constexpr (sizeof(T) <= sizeof(double)) {
return sqrt(m_real * m_real + m_imag * m_imag);
} else {
return sqrtl(m_real * m_real + m_imag * m_imag);
}
}
constexpr T phase() const COMPLEX_NOEXCEPT
{
return atan2(m_imag, m_real);
}
template<AK::Concepts::Arithmetic U, AK::Concepts::Arithmetic V>
static constexpr Complex<T> from_polar(U magnitude, V phase)
{
if constexpr (sizeof(T) <= sizeof(float)) {
return Complex<T>(magnitude * cosf(phase), magnitude * sinf(phase));
} else if constexpr (sizeof(T) <= sizeof(double)) {
return Complex<T>(magnitude * cos(phase), magnitude * sin(phase));
} else {
return Complex<T>(magnitude * cosl(phase), magnitude * sinl(phase));
}
}
# endif
template<AK::Concepts::Arithmetic U>
constexpr Complex<T>& operator=(const Complex<U>& other)
{
m_real = other.real();
m_imag = other.imag();
return *this;
}
template<AK::Concepts::Arithmetic U>
constexpr Complex<T>& operator=(const U& x)
{
m_real = x;
m_imag = 0;
return *this;
}
template<AK::Concepts::Arithmetic U>
constexpr Complex<T> operator+=(const Complex<U>& x)
{
m_real += x.real();
m_imag += x.imag();
return *this;
}
template<AK::Concepts::Arithmetic U>
constexpr Complex<T> operator+=(const U& x)
{
m_real += x.real();
return *this;
}
template<AK::Concepts::Arithmetic U>
constexpr Complex<T> operator-=(const Complex<U>& x)
{
m_real -= x.real();
m_imag -= x.imag();
return *this;
}
template<AK::Concepts::Arithmetic U>
constexpr Complex<T> operator-=(const U& x)
{
m_real -= x.real();
return *this;
}
template<AK::Concepts::Arithmetic U>
constexpr Complex<T> operator*=(const Complex<U>& x)
{
const T real = m_real;
m_real = real * x.real() - m_imag * x.imag();
m_imag = real * x.imag() + m_imag * x.real();
return *this;
}
template<AK::Concepts::Arithmetic U>
constexpr Complex<T> operator*=(const U& x)
{
m_real *= x;
m_imag *= x;
return *this;
}
template<AK::Concepts::Arithmetic U>
constexpr Complex<T> operator/=(const Complex<U>& x)
{
const T real = m_real;
const T divisor = x.real() * x.real() + x.imag() * x.imag();
m_real = (real * x.real() + m_imag * x.imag()) / divisor;
m_imag = (m_imag * x.real() - x.real() * x.imag()) / divisor;
return *this;
}
template<AK::Concepts::Arithmetic U>
constexpr Complex<T> operator/=(const U& x)
{
m_real /= x;
m_imag /= x;
return *this;
}
template<AK::Concepts::Arithmetic U>
constexpr Complex<T> operator+(const Complex<U>& a)
{
Complex<T> x = *this;
x += a;
return x;
}
template<AK::Concepts::Arithmetic U>
constexpr Complex<T> operator+(const U& a)
{
Complex<T> x = *this;
x += a;
return x;
}
template<AK::Concepts::Arithmetic U>
constexpr Complex<T> operator-(const Complex<U>& a)
{
Complex<T> x = *this;
x -= a;
return x;
}
template<AK::Concepts::Arithmetic U>
constexpr Complex<T> operator-(const U& a)
{
Complex<T> x = *this;
x -= a;
return x;
}
template<AK::Concepts::Arithmetic U>
constexpr Complex<T> operator*(const Complex<U>& a)
{
Complex<T> x = *this;
x *= a;
return x;
}
template<AK::Concepts::Arithmetic U>
constexpr Complex<T> operator*(const U& a)
{
Complex<T> x = *this;
x *= a;
return x;
}
template<AK::Concepts::Arithmetic U>
constexpr Complex<T> operator/(const Complex<U>& a)
{
Complex<T> x = *this;
x /= a;
return x;
}
template<AK::Concepts::Arithmetic U>
constexpr Complex<T> operator/(const U& a)
{
Complex<T> x = *this;
x /= a;
return x;
}
template<AK::Concepts::Arithmetic U>
constexpr bool operator==(const Complex<U>& a)
{
return (this->real() == a.real()) && (this->imag() == a.imag());
}
template<AK::Concepts::Arithmetic U>
constexpr bool operator!=(const Complex<U>& a)
{
return !(*this == a);
}
constexpr Complex<T> operator+()
{
return *this;
}
constexpr Complex<T> operator-()
{
return Complex<T>(-m_real, -m_imag);
}
private:
T m_real;
T m_imag;
};
// reverse associativity operators for scalars
template<AK::Concepts::Arithmetic T, AK::Concepts::Arithmetic U>
constexpr Complex<T> operator+(const U& b, const Complex<T>& a)
{
Complex<T> x = a;
x += b;
return x;
}
template<AK::Concepts::Arithmetic T, AK::Concepts::Arithmetic U>
constexpr Complex<T> operator-(const U& b, const Complex<T>& a)
{
Complex<T> x = a;
x -= b;
return x;
}
template<AK::Concepts::Arithmetic T, AK::Concepts::Arithmetic U>
constexpr Complex<T> operator*(const U& b, const Complex<T>& a)
{
Complex<T> x = a;
x *= b;
return x;
}
template<AK::Concepts::Arithmetic T, AK::Concepts::Arithmetic U>
constexpr Complex<T> operator/(const U& b, const Complex<T>& a)
{
Complex<T> x = a;
x /= b;
return x;
}
// some identities
template<AK::Concepts::Arithmetic T>
static constinit Complex<T> complex_real_unit = Complex<T>((T)1, (T)0);
template<AK::Concepts::Arithmetic T>
static constinit Complex<T> complex_imag_unit = Complex<T>((T)0, (T)1);
# ifdef AKCOMPLEX_CAN_USE_MATH_H
template<AK::Concepts::Arithmetic T, AK::Concepts::Arithmetic U>
static constexpr bool approx_eq(const Complex<T>& a, const Complex<U>& b, const double margin = 0.000001)
{
const auto x = const_cast<Complex<T>&>(a) - const_cast<Complex<U>&>(b);
return x.magnitude() <= margin;
}
//complex version of exp()
template<AK::Concepts::Arithmetic T>
static constexpr Complex<T> cexp(const Complex<T>& a)
{
//FIXME: this can probably be faster and not use so many expensive trigonometric functions
if constexpr (sizeof(T) <= sizeof(float)) {
return expf(a.real()) * Complex<T>(cosf(a.imag()), sinf(a.imag()));
} else if constexpr (sizeof(T) <= sizeof(double)) {
return exp(a.real()) * Complex<T>(cos(a.imag()), sin(a.imag()));
} else {
return expl(a.real()) * Complex<T>(cosl(a.imag()), sinl(a.imag()));
}
}
}
# endif
using AK::Complex;
using AK::complex_imag_unit;
using AK::complex_real_unit;
# ifdef AKCOMPLEX_CAN_USE_MATH_H
using AK::approx_eq;
using AK::cexp;
# endif
#endif

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@ -38,12 +38,16 @@ concept Integral = IsIntegral<T>::value;
template<typename T>
concept FloatingPoint = IsFloatingPoint<T>::value;
template<typename T>
concept Arithmetic = IsArithmetic<T>::value;
#endif
}
#if defined(__cpp_concepts) && !defined(__COVERITY__)
using AK::IsArithmetic;
using AK::IsFloatingPoint;
using AK::IsIntegral;

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@ -16,6 +16,7 @@ set(AK_TEST_SOURCES
TestCircularDeque.cpp
TestCircularDuplexStream.cpp
TestCircularQueue.cpp
TestComplex.cpp
TestDistinctNumeric.cpp
TestDoublyLinkedList.cpp
TestEndian.cpp

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AK/Tests/TestComplex.cpp Normal file
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/*
* Copyright (c) 2021, Cesar Torres <shortanemoia@protonmail.com>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <AK/Complex.h>
#include <AK/TestSuite.h>
TEST_CASE(Complex)
{
auto a = Complex<float> { 1.f, 1.f };
auto b = complex_real_unit<double> + Complex<double> { 0, 1 } * 1;
EXPECT_APPROXIMATE(a.real(), b.real());
EXPECT_APPROXIMATE(a.imag(), b.imag());
#ifdef AKCOMPLEX_CAN_USE_MATH_H
EXPECT_APPROXIMATE((complex_imag_unit<float> - complex_imag_unit<float>).magnitude(), 0);
EXPECT_APPROXIMATE((complex_imag_unit<float> + complex_real_unit<float>).magnitude(), sqrt(2));
auto c = Complex<double> { 0., 1. };
auto d = Complex<double>::from_polar(1., M_PI / 2.);
EXPECT_APPROXIMATE(c.real(), d.real());
EXPECT_APPROXIMATE(c.imag(), d.imag());
c = Complex<double> { -1., 1. };
d = Complex<double>::from_polar(sqrt(2.), 3. * M_PI / 4.);
EXPECT_APPROXIMATE(c.real(), d.real());
EXPECT_APPROXIMATE(c.imag(), d.imag());
EXPECT_APPROXIMATE(d.phase(), 3. * M_PI / 4.);
EXPECT_APPROXIMATE(c.magnitude(), d.magnitude());
EXPECT_APPROXIMATE(c.magnitude(), sqrt(2.));
#endif
EXPECT_EQ((complex_imag_unit<double> * complex_imag_unit<double>).real(), -1.);
EXPECT_EQ((complex_imag_unit<double> / complex_imag_unit<double>).real(), 1.);
EXPECT_EQ(Complex(1., 10.) == (Complex<double>(1., 0.) + Complex(0., 10.)), true);
EXPECT_EQ(Complex(1., 10.) != (Complex<double>(1., 1.) + Complex(0., 10.)), true);
#ifdef AKCOMPLEX_CAN_USE_MATH_H
EXPECT_EQ(approx_eq(Complex<int>(1), Complex<float>(1.0000004f)), true);
EXPECT_APPROXIMATE(cexp(Complex<double>(0., 1.) * M_PI).real(), -1.);
#endif
}
TEST_MAIN(Complex)