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58 lines
2.0 KiB
C++
58 lines
2.0 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_RANK2UPDATE_H
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#define EIGEN_RANK2UPDATE_H
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namespace internal {
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/* Optimized selfadjoint matrix += alpha * uv' + conj(alpha)*vu'
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* This is the low-level version of SelfadjointRank2Update.h
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*/
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template<typename Scalar, typename Index, int UpLo>
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struct rank2_update_selector
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{
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static void run(Index size, Scalar* mat, Index stride, const Scalar* u, const Scalar* v, Scalar alpha)
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{
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typedef Map<const Matrix<Scalar,Dynamic,1> > OtherMap;
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for (Index i=0; i<size; ++i)
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{
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Map<Matrix<Scalar,Dynamic,1> >(mat+stride*i+(UpLo==Lower ? i : 0), UpLo==Lower ? size-i : (i+1)) +=
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conj(alpha) * conj(u[i]) * OtherMap(v+(UpLo==Lower ? i : 0), UpLo==Lower ? size-i : (i+1))
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+ alpha * conj(v[i]) * OtherMap(u+(UpLo==Lower ? i : 0), UpLo==Lower ? size-i : (i+1));
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}
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}
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};
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/* Optimized selfadjoint matrix += alpha * uv' + conj(alpha)*vu'
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* The matrix is in packed form.
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*/
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template<typename Scalar, typename Index, int UpLo>
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struct packed_rank2_update_selector
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{
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static void run(Index size, Scalar* mat, const Scalar* u, const Scalar* v, Scalar alpha)
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{
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typedef Map<const Matrix<Scalar,Dynamic,1> > OtherMap;
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Index offset = 0;
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for (Index i=0; i<size; ++i)
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{
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Map<Matrix<Scalar,Dynamic,1> >(mat+offset, UpLo==Lower ? size-i : (i+1)) +=
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conj(alpha) * conj(u[i]) * OtherMap(v+(UpLo==Lower ? i : 0), UpLo==Lower ? size-i : (i+1))
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+ alpha * conj(v[i]) * OtherMap(u+(UpLo==Lower ? i : 0), UpLo==Lower ? size-i : (i+1));
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//FIXME This should be handled outside.
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mat[offset+(UpLo==Lower ? 0 : i)] = real(mat[offset+(UpLo==Lower ? 0 : i)]);
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offset += UpLo==Lower ? size-i : (i+1);
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}
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}
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};
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} // end namespace internal
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#endif // EIGEN_RANK2UPDATE_H
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