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96 lines
3.7 KiB
C++
96 lines
3.7 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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// 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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/*
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* NOTE: This file is the modified version of [s,d,c,z]snode_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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#ifndef SPARSELU_SNODE_DFS_H
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#define SPARSELU_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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* \return 0 on success, > 0 size of the memory when memory allocation failed
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*/
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template <typename MatrixType, typename IndexVector, typename ScalarVector>
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int LU_snode_dfs(const int jcol, const int kcol,const MatrixType& mat, IndexVector& xprune, IndexVector& marker, LU_GlobalLU_t<IndexVector, ScalarVector>& glu)
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{
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typedef typename IndexVector::Scalar Index;
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int mem;
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Index nsuper = ++glu.supno(jcol); // Next available supernode number
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int nextl = glu.xlsub(jcol); //Index of the starting location of the jcol-th column in lsub
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int krow,kmark;
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for (int i = jcol; i <=kcol; i++)
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{
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// For each nonzero in A(*,i)
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for (typename MatrixType::InnerIterator it(mat, i); it; ++it)
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{
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krow = it.row();
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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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glu.lsub(nextl++) = krow;
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if( nextl >= glu.nzlmax )
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{
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mem = LUMemXpand<IndexVector>(glu.lsub, glu.nzlmax, nextl, LSUB, glu.num_expansions);
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if (mem) return mem; // Memory expansion failed... Return the memory allocated so far
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}
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}
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}
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glu.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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Index new_next = nextl + (nextl - glu.xlsub(jcol));
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while (new_next > glu.nzlmax)
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{
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mem = LUMemXpand<IndexVector>(glu.lsub, glu.nzlmax, nextl, LSUB, glu.num_expansions);
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if (mem) return mem; // Memory expansion failed... Return the memory allocated so far
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}
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Index ifrom, ito = nextl;
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for (ifrom = glu.xlsub(jcol); ifrom < nextl;)
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glu.lsub(ito++) = glu.lsub(ifrom++);
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for (int i = jcol+1; i <=kcol; i++) glu.xlsub(i) = nextl;
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nextl = ito;
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}
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glu.xsup(nsuper+1) = kcol + 1; // Start of next available supernode
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glu.supno(kcol+1) = nsuper;
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xprune(kcol) = nextl;
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glu.xlsub(kcol+1) = nextl;
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return 0;
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}
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#endif |