75 lines
3.3 KiB
C++
75 lines
3.3 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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enum { IsLower = (Mode & Lower) == Lower };
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static void run(Index size, const LhsScalar* lhs, RhsScalar* rhs) {
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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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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)))
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.sum();
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if (!(Mode & UnitDiag)) 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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enum { IsLower = (Mode & Lower) == Lower };
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static void run(Index size, const LhsScalar* lhs, RhsScalar* rhs) {
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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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Index i = IsLower ? pi : size - pi - 1;
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Index r = size - pi - 1;
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if (!(Mode & UnitDiag)) 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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static void run(Index size, const LhsScalar* lhs, RhsScalar* rhs) {
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packed_triangular_solve_vector<LhsScalar, RhsScalar, Index, OnTheLeft,
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((Mode & Upper) == Upper ? Lower : Upper) | (Mode & UnitDiag), Conjugate,
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StorageOrder == RowMajor ? ColMajor : RowMajor>::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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