117 lines
2.7 KiB
C++
117 lines
2.7 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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// Eigen is free software; you can redistribute it and/or
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// modify it under the terms of the GNU Lesser General Public
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// License as published by the Free Software Foundation; either
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// version 3 of the License, or (at your option) any later version.
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//
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// Alternatively, you can redistribute it and/or
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// modify it under the terms of the GNU General Public License as
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// published by the Free Software Foundation; either version 2 of
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// the License, or (at your option) any later version.
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//
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// Eigen is distributed in the hope that it will be useful, but WITHOUT ANY
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// WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
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// FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License or the
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// GNU General Public License for more details.
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//
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// You should have received a copy of the GNU Lesser General Public
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// License and a copy of the GNU General Public License along with
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// Eigen. If not, see <http://www.gnu.org/licenses/>.
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#ifndef EIGEN_STEM_FUNCTION
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#define EIGEN_STEM_FUNCTION
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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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#endif // EIGEN_STEM_FUNCTION
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