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89 lines
3.1 KiB
C++
89 lines
3.1 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) 2012 Chen-Pang He <jdh8@ms63.hinet.net>
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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_PACKED_TRIANGULAR_SOLVER_VECTOR_H
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#define EIGEN_PACKED_TRIANGULAR_SOLVER_VECTOR_H
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namespace internal {
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template<typename LhsScalar, typename RhsScalar, typename Index, int Side, int Mode, bool Conjugate, int StorageOrder>
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struct packed_triangular_solve_vector;
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// forward and backward substitution, row-major, rhs is a vector
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template<typename LhsScalar, typename RhsScalar, typename Index, int Mode, bool Conjugate>
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struct packed_triangular_solve_vector<LhsScalar, RhsScalar, Index, OnTheLeft, Mode, Conjugate, RowMajor>
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{
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enum {
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IsLower = (Mode&Lower)==Lower
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};
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static void run(Index size, const LhsScalar* lhs, RhsScalar* rhs)
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{
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internal::conj_if<Conjugate> cj;
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typedef Map<const Matrix<LhsScalar,Dynamic,1> > LhsMap;
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typedef typename conj_expr_if<Conjugate,LhsMap>::type ConjLhsType;
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lhs += IsLower ? 0 : (size*(size+1)>>1)-1;
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for(Index pi=0; pi<size; ++pi)
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{
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Index i = IsLower ? pi : size-pi-1;
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Index s = IsLower ? 0 : 1;
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if (pi>0)
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rhs[i] -= (ConjLhsType(LhsMap(lhs+s,pi))
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.cwiseProduct(Map<const Matrix<RhsScalar,Dynamic,1> >(rhs+(IsLower ? 0 : i+1),pi))).sum();
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if (!(Mode & UnitDiag))
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rhs[i] /= cj(lhs[IsLower ? i : 0]);
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IsLower ? lhs += pi+1 : lhs -= pi+2;
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}
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}
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};
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// forward and backward substitution, column-major, rhs is a vector
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template<typename LhsScalar, typename RhsScalar, typename Index, int Mode, bool Conjugate>
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struct packed_triangular_solve_vector<LhsScalar, RhsScalar, Index, OnTheLeft, Mode, Conjugate, ColMajor>
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{
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enum {
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IsLower = (Mode&Lower)==Lower
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};
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static void run(Index size, const LhsScalar* lhs, RhsScalar* rhs)
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{
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internal::conj_if<Conjugate> cj;
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typedef Map<const Matrix<LhsScalar,Dynamic,1> > LhsMap;
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typedef typename conj_expr_if<Conjugate,LhsMap>::type ConjLhsType;
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lhs += IsLower ? 0 : size*(size-1)>>1;
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for(Index pi=0; pi<size; ++pi)
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{
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Index i = IsLower ? pi : size-pi-1;
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Index r = size - pi - 1;
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if (!(Mode & UnitDiag))
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rhs[i] /= cj(lhs[IsLower ? 0 : i]);
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if (r>0)
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Map<Matrix<RhsScalar,Dynamic,1> >(rhs+(IsLower? i+1 : 0),r) -=
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rhs[i] * ConjLhsType(LhsMap(lhs+(IsLower? 1 : 0),r));
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IsLower ? lhs += size-pi : lhs -= r;
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}
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}
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};
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template<typename LhsScalar, typename RhsScalar, typename Index, int Mode, bool Conjugate, int StorageOrder>
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struct packed_triangular_solve_vector<LhsScalar, RhsScalar, Index, OnTheRight, Mode, Conjugate, StorageOrder>
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{
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static void run(Index size, const LhsScalar* lhs, RhsScalar* rhs)
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{
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packed_triangular_solve_vector<LhsScalar,RhsScalar,Index,OnTheLeft,
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((Mode&Upper)==Upper ? Lower : Upper) | (Mode&UnitDiag),
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Conjugate,StorageOrder==RowMajor?ColMajor:RowMajor
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>::run(size, lhs, rhs);
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}
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};
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} // end namespace internal
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#endif // EIGEN_PACKED_TRIANGULAR_SOLVER_VECTOR_H
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