libcruft-util/polynomial.hpp
Danny Robson 0e3fa05f05 build: migrate from ipp files to pure hpp files
ipp files weren't a great way of keeping things clean, and IDEs have a
little trouble dealing with the split configuration. this simplifies
debugging a great deal.
2018-02-28 11:49:13 +11:00

48 lines
1.3 KiB
C++

/*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
* Copyright 2015 Danny Robson <danny@nerdcruft.net>
*/
#ifndef CRUFT_UTIL_POLYNOMIAL_HPP
#define CRUFT_UTIL_POLYNOMIAL_HPP
#include <array>
#include <cstdlib>
namespace util::polynomial {
// Invalid solutions are represented by NaN. They are guaranteed to
// be at the end of the solution list, so they are safe to skip on the
// first instance.
template <size_t S>
std::array<float,S>
roots (std::array<float,S+1>);
template <size_t S, typename T, typename U>
T
eval (std::array<T,S> coeffs, U x)
{
U x_ = 1.f;
T sum {0.f};
for (size_t i = 0; i < S; ++i) {
sum += coeffs[S-i-1] * x_;
x_ *= x;
}
return sum;
}
}
#endif