40 lines
945 B
C++
40 lines
945 B
C++
/*
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* This Source Code Form is subject to the terms of the Mozilla Public
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* License, v. 2.0. If a copy of the MPL was not distributed with this
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* file, You can obtain one at http://mozilla.org/MPL/2.0/.
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*
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* Copyright 2015 Danny Robson <danny@nerdcruft.net>
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*/
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#ifndef CRUFT_UTIL_POLYNOMIAL_HPP
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#define CRUFT_UTIL_POLYNOMIAL_HPP
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#include <array>
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#include <cstdlib>
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namespace cruft::polynomial {
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// Invalid solutions are represented by NaN. They are guaranteed to
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// be at the end of the solution list, so they are safe to skip on the
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// first instance.
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template <size_t S>
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std::array<float,S>
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roots (std::array<float,S+1>);
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template <size_t S, typename T, typename U>
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T
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eval (std::array<T,S> coeffs, U x)
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{
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U x_ = 1.f;
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T sum {0.f};
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for (size_t i = 0; i < S; ++i) {
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sum += coeffs[S-i-1] * x_;
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x_ *= x;
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}
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return sum;
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}
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}
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#endif
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