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106 lines
2.0 KiB
C++
106 lines
2.0 KiB
C++
// This file is part of Eigen, a lightweight C++ template library
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// for linear algebra.
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//
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// Copyright (C) 2010 Jitse Niesen <jitse@maths.leeds.ac.uk>
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//
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// This Source Code Form is subject to the terms of the Mozilla
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// Public License v. 2.0. If a copy of the MPL was not distributed
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// with this file, You can obtain one at http://mozilla.org/MPL/2.0/.
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#ifndef EIGEN_STEM_FUNCTION
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#define EIGEN_STEM_FUNCTION
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namespace Eigen {
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/** \ingroup MatrixFunctions_Module
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* \brief Stem functions corresponding to standard mathematical functions.
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*/
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template <typename Scalar>
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class StdStemFunctions
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{
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public:
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/** \brief The exponential function (and its derivatives). */
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static Scalar exp(Scalar x, int)
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{
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return std::exp(x);
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}
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/** \brief Cosine (and its derivatives). */
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static Scalar cos(Scalar x, int n)
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{
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Scalar res;
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switch (n % 4) {
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case 0:
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res = std::cos(x);
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break;
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case 1:
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res = -std::sin(x);
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break;
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case 2:
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res = -std::cos(x);
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break;
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case 3:
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res = std::sin(x);
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break;
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}
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return res;
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}
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/** \brief Sine (and its derivatives). */
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static Scalar sin(Scalar x, int n)
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{
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Scalar res;
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switch (n % 4) {
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case 0:
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res = std::sin(x);
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break;
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case 1:
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res = std::cos(x);
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break;
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case 2:
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res = -std::sin(x);
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break;
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case 3:
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res = -std::cos(x);
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break;
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}
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return res;
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}
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/** \brief Hyperbolic cosine (and its derivatives). */
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static Scalar cosh(Scalar x, int n)
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{
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Scalar res;
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switch (n % 2) {
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case 0:
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res = std::cosh(x);
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break;
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case 1:
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res = std::sinh(x);
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break;
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}
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return res;
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}
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/** \brief Hyperbolic sine (and its derivatives). */
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static Scalar sinh(Scalar x, int n)
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{
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Scalar res;
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switch (n % 2) {
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case 0:
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res = std::sinh(x);
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break;
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case 1:
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res = std::cosh(x);
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break;
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}
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return res;
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}
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}; // end of class StdStemFunctions
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} // end namespace Eigen
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#endif // EIGEN_STEM_FUNCTION
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