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88 lines
4.1 KiB
C++
88 lines
4.1 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 Désiré Nuentsa-Wakam <desire.nuentsa_wakam@inria.fr>
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//
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// Eigen is free software; you can redistribute it and/or
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// modify it under the terms of the GNU Lesser General Public
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// License as published by the Free Software Foundation; either
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// version 3 of the License, or (at your option) any later version.
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//
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// Alternatively, you can redistribute it and/or
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// modify it under the terms of the GNU General Public License as
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// published by the Free Software Foundation; either version 2 of
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// the License, or (at your option) any later version.
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//
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// Eigen is distributed in the hope that it will be useful, but WITHOUT ANY
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// WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
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// FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License or the
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// GNU General Public License for more details.
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//
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// You should have received a copy of the GNU Lesser General Public
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// License and a copy of the GNU General Public License along with
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// Eigen. If not, see <http://www.gnu.org/licenses/>.
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/*
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* NOTE: This file is the modified version of dsnode_bmod.c file in SuperLU
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* -- SuperLU routine (version 3.0) --
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* Univ. of California Berkeley, Xerox Palo Alto Research Center,
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* and Lawrence Berkeley National Lab.
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* October 15, 2003
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*
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* Copyright (c) 1994 by Xerox Corporation. All rights reserved.
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*
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* THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY
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* EXPRESSED OR IMPLIED. ANY USE IS AT YOUR OWN RISK.
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*
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* Permission is hereby granted to use or copy this program for any
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* purpose, provided the above notices are retained on all copies.
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* Permission to modify the code and to distribute modified code is
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* granted, provided the above notices are retained, and a notice that
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* the code was modified is included with the above copyright notice.
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*/
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#ifndef SPARSELU_SNODE_BMOD_H
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#define SPARSELU_SNODE_BMOD_H
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template <typename IndexVector, typename ScalarVector>
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int LU_snode_bmod (const int jcol, const int fsupc, ScalarVector& dense, LU_GlobalLU_t<IndexVector,ScalarVector>& glu)
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{
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typedef typename ScalarVector::Scalar Scalar;
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IndexVector& lsub = glu.lsub; // Compressed row subscripts of ( rectangular supernodes ??)
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IndexVector& xlsub = glu.xlsub; // xlsub[j] is the starting location of the j-th column in lsub(*)
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ScalarVector& lusup = glu.lusup; // Numerical values of the rectangular supernodes
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IndexVector& xlusup = glu.xlusup; // xlusup[j] is the starting location of the j-th column in lusup(*)
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int nextlu = xlusup(jcol); // Starting location of the next column to add
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int irow, isub;
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// Process the supernodal portion of L\U[*,jcol]
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for (isub = xlsub(fsupc); isub < xlsub(fsupc+1); isub++)
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{
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irow = lsub(isub);
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lusup(nextlu) = dense(irow);
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dense(irow) = 0;
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++nextlu;
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}
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xlusup(jcol + 1) = nextlu; // Initialize xlusup for next column ( jcol+1 )
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if (fsupc < jcol ){
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int luptr = xlusup(fsupc); // points to the first column of the supernode
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int nsupr = xlsub(fsupc + 1) -xlsub(fsupc); //Number of rows in the supernode
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int nsupc = jcol - fsupc; // Number of columns in the supernodal portion of L\U[*,jcol]
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int ufirst = xlusup(jcol); // points to the beginning of column jcol in supernode L\U(jsupno)
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int nrow = nsupr - nsupc; // Number of rows in the off-diagonal blocks
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// Solve the triangular system for U(fsupc:jcol, jcol) with L(fspuc:jcol, fsupc:jcol)
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Map<Matrix<Scalar,Dynamic,Dynamic>,0,OuterStride<> > A( &(lusup.data()[luptr]), nsupc, nsupc, OuterStride<>(nsupr) );
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VectorBlock<ScalarVector> u(lusup, ufirst, nsupc);
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u = A.template triangularView<UnitLower>().solve(u); // Call the Eigen dense triangular solve interface
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// Update the trailing part of the column jcol U(jcol:jcol+nrow, jcol) using L(jcol:jcol+nrow, fsupc:jcol) and U(fsupc:jcol)
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new (&A) Map<Matrix<Scalar,Dynamic,Dynamic>,0,OuterStride<> > ( &(lusup.data()[luptr+nsupc]), nrow, nsupc, OuterStride<>(nsupr) );
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VectorBlock<ScalarVector> l(lusup, ufirst+nsupc, nrow);
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l = l - A * u;
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}
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return 0;
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}
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#endif |