mirror of
https://gitlab.com/libeigen/eigen.git
synced 2025-07-26 06:44:27 +08:00
116 lines
2.2 KiB
C++
116 lines
2.2 KiB
C++
// This file is part of Eigen, a lightweight C++ template library
|
|
// for linear algebra.
|
|
//
|
|
// Copyright (C) 2010, 2013 Jitse Niesen <jitse@maths.leeds.ac.uk>
|
|
//
|
|
// This Source Code Form is subject to the terms of the Mozilla
|
|
// Public License v. 2.0. If a copy of the MPL was not distributed
|
|
// with this file, You can obtain one at http://mozilla.org/MPL/2.0/.
|
|
|
|
#ifndef EIGEN_STEM_FUNCTION
|
|
#define EIGEN_STEM_FUNCTION
|
|
|
|
// IWYU pragma: private
|
|
#include "./InternalHeaderCheck.h"
|
|
|
|
namespace Eigen {
|
|
|
|
namespace internal {
|
|
|
|
/** \brief The exponential function (and its derivatives). */
|
|
template <typename Scalar>
|
|
Scalar stem_function_exp(Scalar x, int) {
|
|
using std::exp;
|
|
return exp(x);
|
|
}
|
|
|
|
/** \brief Cosine (and its derivatives). */
|
|
template <typename Scalar>
|
|
Scalar stem_function_cos(Scalar x, int n) {
|
|
using std::cos;
|
|
using std::sin;
|
|
Scalar res;
|
|
|
|
switch (n % 4) {
|
|
case 0:
|
|
res = std::cos(x);
|
|
break;
|
|
case 1:
|
|
res = -std::sin(x);
|
|
break;
|
|
case 2:
|
|
res = -std::cos(x);
|
|
break;
|
|
case 3:
|
|
res = std::sin(x);
|
|
break;
|
|
}
|
|
return res;
|
|
}
|
|
|
|
/** \brief Sine (and its derivatives). */
|
|
template <typename Scalar>
|
|
Scalar stem_function_sin(Scalar x, int n) {
|
|
using std::cos;
|
|
using std::sin;
|
|
Scalar res;
|
|
|
|
switch (n % 4) {
|
|
case 0:
|
|
res = std::sin(x);
|
|
break;
|
|
case 1:
|
|
res = std::cos(x);
|
|
break;
|
|
case 2:
|
|
res = -std::sin(x);
|
|
break;
|
|
case 3:
|
|
res = -std::cos(x);
|
|
break;
|
|
}
|
|
return res;
|
|
}
|
|
|
|
/** \brief Hyperbolic cosine (and its derivatives). */
|
|
template <typename Scalar>
|
|
Scalar stem_function_cosh(Scalar x, int n) {
|
|
using std::cosh;
|
|
using std::sinh;
|
|
Scalar res;
|
|
|
|
switch (n % 2) {
|
|
case 0:
|
|
res = std::cosh(x);
|
|
break;
|
|
case 1:
|
|
res = std::sinh(x);
|
|
break;
|
|
}
|
|
return res;
|
|
}
|
|
|
|
/** \brief Hyperbolic sine (and its derivatives). */
|
|
template <typename Scalar>
|
|
Scalar stem_function_sinh(Scalar x, int n) {
|
|
using std::cosh;
|
|
using std::sinh;
|
|
Scalar res;
|
|
|
|
switch (n % 2) {
|
|
case 0:
|
|
res = std::sinh(x);
|
|
break;
|
|
case 1:
|
|
res = std::cosh(x);
|
|
break;
|
|
}
|
|
return res;
|
|
}
|
|
|
|
} // end namespace internal
|
|
|
|
} // end namespace Eigen
|
|
|
|
#endif // EIGEN_STEM_FUNCTION
|