mirror of
https://github.com/boostorg/math.git
synced 2025-05-11 21:33:52 +00:00
108 lines
3.2 KiB
C++
108 lines
3.2 KiB
C++
/*
|
|
* Copyright Nick Thompson, 2024
|
|
* Use, modification and distribution are subject to the
|
|
* Boost Software License, Version 1.0. (See accompanying file
|
|
* LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
|
|
*/
|
|
#ifndef TEST_FUNCTIONS_FOR_OPTIMIZATION_HPP
|
|
#define TEST_FUNCTIONS_FOR_OPTIMIZATION_HPP
|
|
#include <array>
|
|
#include <vector>
|
|
#include <boost/math/constants/constants.hpp>
|
|
#if __has_include(<boost/units/systems/si/length.hpp>)
|
|
// This is the only system boost.units still works on.
|
|
// I imagine this will start to fail at some point,
|
|
// and we'll have to remove this test as well.
|
|
#if defined(__APPLE__)
|
|
#define BOOST_MATH_TEST_UNITS_COMPATIBILITY 1
|
|
#include <boost/units/systems/si/length.hpp>
|
|
#include <boost/units/systems/si/area.hpp>
|
|
#include <boost/units/cmath.hpp>
|
|
#include <boost/units/quantity.hpp>
|
|
#include <boost/units/systems/si/io.hpp>
|
|
using namespace boost::units;
|
|
using namespace boost::units::si;
|
|
|
|
// This *should* return an area, but see: https://github.com/boostorg/units/issues/58
|
|
// This sadly prevents std::atomic<quantity<area>>.
|
|
// Nonetheless, we *do* get some information making the argument type dimensioned,
|
|
// even if it would be better to get the full information:
|
|
double dimensioned_sphere(std::vector<quantity<length>> const & v) {
|
|
quantity<area> r(0.0*meters*meters);
|
|
for (auto const & x : v) {
|
|
r += (x * x);
|
|
}
|
|
quantity<area> scale(1.0*meters*meters);
|
|
return static_cast<double>(r/scale);
|
|
}
|
|
#endif
|
|
#endif
|
|
|
|
// Taken from: https://en.wikipedia.org/wiki/Test_functions_for_optimization
|
|
template <typename Real> Real ackley(std::array<Real, 2> const &v) {
|
|
using std::sqrt;
|
|
using std::cos;
|
|
using std::exp;
|
|
using boost::math::constants::two_pi;
|
|
using boost::math::constants::e;
|
|
Real x = v[0];
|
|
Real y = v[1];
|
|
Real arg1 = -sqrt((x * x + y * y) / 2) / 5;
|
|
Real arg2 = cos(two_pi<Real>() * x) + cos(two_pi<Real>() * y);
|
|
return -20 * exp(arg1) - exp(arg2 / 2) + 20 + e<Real>();
|
|
}
|
|
|
|
template <typename Real> auto rosenbrock_saddle(std::array<Real, 2> const &v) {
|
|
auto x = v[0];
|
|
auto y = v[1];
|
|
return 100 * (x * x - y) * (x * x - y) + (1 - x) * (1 - x);
|
|
}
|
|
|
|
|
|
template <class Real> Real rastrigin(std::vector<Real> const &v) {
|
|
using std::cos;
|
|
using boost::math::constants::two_pi;
|
|
auto A = static_cast<Real>(10);
|
|
auto y = static_cast<Real>(10 * v.size());
|
|
for (auto x : v) {
|
|
y += x * x - A * cos(two_pi<Real>() * x);
|
|
}
|
|
return y;
|
|
}
|
|
|
|
// Useful for testing return-type != scalar argument type,
|
|
// and robustness to NaNs:
|
|
double sphere(std::vector<float> const &v) {
|
|
double r = 0.0;
|
|
for (auto x : v) {
|
|
double x_ = static_cast<double>(x);
|
|
r += x_ * x_;
|
|
}
|
|
if (r >= 1) {
|
|
return std::numeric_limits<double>::quiet_NaN();
|
|
}
|
|
return r;
|
|
}
|
|
|
|
template<typename Real>
|
|
Real three_hump_camel(std::array<Real, 2> const & v) {
|
|
Real x = v[0];
|
|
Real y = v[1];
|
|
auto xsq = x*x;
|
|
return 2*xsq - (1 + Real(1)/Real(20))*xsq*xsq + xsq*xsq*xsq/6 + x*y + y*y;
|
|
}
|
|
|
|
// Minima occurs at (3, 1/2) with value 0:
|
|
template<typename Real>
|
|
Real beale(std::array<Real, 2> const & v) {
|
|
Real x = v[0];
|
|
Real y = v[1];
|
|
Real t1 = Real(3)/Real(2) -x + x*y;
|
|
Real t2 = Real(9)/Real(4) -x + x*y*y;
|
|
Real t3 = Real(21)/Real(8) -x + x*y*y*y;
|
|
return t1*t1 + t2*t2 + t3*t3;
|
|
}
|
|
|
|
|
|
#endif
|