libcruft-util/test/polynomial.cpp

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2015-01-21 23:40:45 +11:00
#include "polynomial.hpp"
#include "float.hpp"
#include "debug.hpp"
#include <algorithm>
#include <cmath>
#include <limits>
int
main (int, char**)
{
auto nan = std::numeric_limits<float>::quiet_NaN ();
struct {
std::array<float,4> coeffs;
std::array<float,3> solutions;
} CUBICS [] = {
{ { 0, 0, -8, 7 }, { 7.f / 8, nan, nan } },
{ { 0, 4, -8, 2 }, { 0.292893f, 1.70710f, nan } },
{ { 1, 0, 0, 0 }, { 0, nan, nan } },
{ { 1, 0, 2, 0 }, { 0, nan, nan } },
{ { -2, 2, -2, 2 }, { 1, nan, nan } },
{ { 1, 0, 0, 2 }, { -std::cbrt(2.f), nan, nan } },
{ { 2, -3, 8, -2 }, { 0.2728376017309678f, nan, nan } },
{ { 1, 4, -8, 7 }, { -5.6389f, nan, nan } },
{ { 1, 3, -6, -8 }, { -4, -1, 2, } },
};
for (auto &i: CUBICS) {
auto s = util::polynomial::solve (i.coeffs);
std::sort (s.begin (), s.end ());
for (size_t j = 0; j < 3; ++j) {
bool equal = ieee_single::almost_equal (i.solutions[j], s[j]);
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bool invalid = std::isnan (i.solutions[j]) && std::isnan (s[j]);
CHECK (equal || invalid);
}
}
}