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author | jjesswan <jessica_wan@brown.edu> | 2024-04-22 21:56:26 -0400 |
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committer | jjesswan <jessica_wan@brown.edu> | 2024-04-22 21:56:26 -0400 |
commit | a556b45abf18f1bd509daaf63b66b7d55e9fd291 (patch) | |
tree | bc9b8a2d184c12aee236e7f9f276a34b84ca552d /engine-ocean/Eigen/src/LU/Determinant.h | |
parent | cd7c76017a12bb548036571c1ff13e551369d06d (diff) |
add engine version
Diffstat (limited to 'engine-ocean/Eigen/src/LU/Determinant.h')
-rw-r--r-- | engine-ocean/Eigen/src/LU/Determinant.h | 117 |
1 files changed, 117 insertions, 0 deletions
diff --git a/engine-ocean/Eigen/src/LU/Determinant.h b/engine-ocean/Eigen/src/LU/Determinant.h new file mode 100644 index 0000000..3a41e6f --- /dev/null +++ b/engine-ocean/Eigen/src/LU/Determinant.h @@ -0,0 +1,117 @@ +// This file is part of Eigen, a lightweight C++ template library +// for linear algebra. +// +// Copyright (C) 2008 Benoit Jacob <jacob.benoit.1@gmail.com> +// +// 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_DETERMINANT_H +#define EIGEN_DETERMINANT_H + +namespace Eigen { + +namespace internal { + +template<typename Derived> +EIGEN_DEVICE_FUNC +inline const typename Derived::Scalar bruteforce_det3_helper +(const MatrixBase<Derived>& matrix, int a, int b, int c) +{ + return matrix.coeff(0,a) + * (matrix.coeff(1,b) * matrix.coeff(2,c) - matrix.coeff(1,c) * matrix.coeff(2,b)); +} + +template<typename Derived, + int DeterminantType = Derived::RowsAtCompileTime +> struct determinant_impl +{ + static inline typename traits<Derived>::Scalar run(const Derived& m) + { + if(Derived::ColsAtCompileTime==Dynamic && m.rows()==0) + return typename traits<Derived>::Scalar(1); + return m.partialPivLu().determinant(); + } +}; + +template<typename Derived> struct determinant_impl<Derived, 1> +{ + static inline EIGEN_DEVICE_FUNC + typename traits<Derived>::Scalar run(const Derived& m) + { + return m.coeff(0,0); + } +}; + +template<typename Derived> struct determinant_impl<Derived, 2> +{ + static inline EIGEN_DEVICE_FUNC + typename traits<Derived>::Scalar run(const Derived& m) + { + return m.coeff(0,0) * m.coeff(1,1) - m.coeff(1,0) * m.coeff(0,1); + } +}; + +template<typename Derived> struct determinant_impl<Derived, 3> +{ + static inline EIGEN_DEVICE_FUNC + typename traits<Derived>::Scalar run(const Derived& m) + { + return bruteforce_det3_helper(m,0,1,2) + - bruteforce_det3_helper(m,1,0,2) + + bruteforce_det3_helper(m,2,0,1); + } +}; + +template<typename Derived> struct determinant_impl<Derived, 4> +{ + typedef typename traits<Derived>::Scalar Scalar; + static EIGEN_DEVICE_FUNC + Scalar run(const Derived& m) + { + Scalar d2_01 = det2(m, 0, 1); + Scalar d2_02 = det2(m, 0, 2); + Scalar d2_03 = det2(m, 0, 3); + Scalar d2_12 = det2(m, 1, 2); + Scalar d2_13 = det2(m, 1, 3); + Scalar d2_23 = det2(m, 2, 3); + Scalar d3_0 = det3(m, 1,d2_23, 2,d2_13, 3,d2_12); + Scalar d3_1 = det3(m, 0,d2_23, 2,d2_03, 3,d2_02); + Scalar d3_2 = det3(m, 0,d2_13, 1,d2_03, 3,d2_01); + Scalar d3_3 = det3(m, 0,d2_12, 1,d2_02, 2,d2_01); + return internal::pmadd(-m(0,3),d3_0, m(1,3)*d3_1) + + internal::pmadd(-m(2,3),d3_2, m(3,3)*d3_3); + } +protected: + static EIGEN_DEVICE_FUNC + Scalar det2(const Derived& m, Index i0, Index i1) + { + return m(i0,0) * m(i1,1) - m(i1,0) * m(i0,1); + } + + static EIGEN_DEVICE_FUNC + Scalar det3(const Derived& m, Index i0, const Scalar& d0, Index i1, const Scalar& d1, Index i2, const Scalar& d2) + { + return internal::pmadd(m(i0,2), d0, internal::pmadd(-m(i1,2), d1, m(i2,2)*d2)); + } +}; + +} // end namespace internal + +/** \lu_module + * + * \returns the determinant of this matrix + */ +template<typename Derived> +EIGEN_DEVICE_FUNC +inline typename internal::traits<Derived>::Scalar MatrixBase<Derived>::determinant() const +{ + eigen_assert(rows() == cols()); + typedef typename internal::nested_eval<Derived,Base::RowsAtCompileTime>::type Nested; + return internal::determinant_impl<typename internal::remove_all<Nested>::type>::run(derived()); +} + +} // end namespace Eigen + +#endif // EIGEN_DETERMINANT_H |