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119 lines
4.3 KiB
C++
119 lines
4.3 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 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_dfs.c file in SuperLU
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* -- SuperLU routine (version 2.0) --
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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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* November 15, 1997
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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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#ifdef EIGEN_SNODE_DFS_H
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#define EIGEN_SNODE_DFS_H
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/**
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* \brief Determine the union of the row structures of those columns within the relaxed snode.
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* NOTE: The relaxed snodes are leaves of the supernodal etree, therefore,
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* the portion outside the rectangular supernode must be zero.
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*
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* \param jcol start of the supernode
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* \param kcol end of the supernode
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* \param asub Row indices
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* \param colptr Pointer to the beginning of each column
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* \param xprune (out) The pruned tree ??
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* \param marker (in/out) working vector
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*/
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template <typename Index>
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int SparseLU::LU_snode_dfs(const int jcol, const int kcol, const VectorXi* asub, const VectorXi* colptr,
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VectorXi& xprune, VectorXi& marker, LU_GlobalLu_t *m_Glu)
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{
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VectorXi& xsup = m_Glu->xsup;
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VectorXi& supno = m_Glu->supno; // Supernode number corresponding to this column
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VectorXi& lsub = m_Glu->lsub;
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VectorXi& xlsub = m_Glu->xlsub;
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int nsuper = ++supno(jcol); // Next available supernode number
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register int nextl = xlsub(jcol); //Index of the starting location of the jcol-th column in lsub
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register int i,k;
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int krow,kmark;
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for (i = jcol; i <=kcol; i++)
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{
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// For each nonzero in A(*,i)
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for (k = colptr(i); k < colptr(i+1); k++)
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{
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krow = asub(k);
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kmark = marker(krow);
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if ( kmark != kcol )
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{
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// First time to visit krow
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marker(krow) = kcol;
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lsub(nextl++) = krow;
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if( nextl >= nzlmax )
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{
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m_Glu->lsub = LUMemXpand<Index>(jcol, nextl, LSUB, nzlmax);
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m_Glu->nzlmax = nzlmax;
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lsub = m_Glu->lsub;
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}
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}
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}
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supno(i) = nsuper;
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}
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// If supernode > 1, then make a copy of the subscripts for pruning
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if (jcol < kcol)
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{
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int new_next = nextl + (nextl - xlsub(jcol));
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while (new_next > nzlmax)
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{
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m_Glu->lsub = LUMemXpand<Index>(jcol, nextl, LSUB, &nzlmax);
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m_Glu->nzlmax= nzlmax;
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lsub = m_Glu->lsub;
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}
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int ifrom, ito = nextl;
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for (ifrom = xlsub(jcol); ifrom < nextl;)
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lsub(ito++) = lsub(ifrom++);
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for (i = jcol+1; i <=kcol; i++)xlsub(i) = nextl;
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nextl = ito;
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}
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xsup(nsuper+1) = kcol + 1; // Start of next available supernode
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supno(kcol+1) = nsuper;
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xprune(kcol) = nextl;
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xlsub(kcol+1) = nextl;
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return 0;
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}
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#endif |