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Eigen
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00001 // This file is part of Eigen, a lightweight C++ template library 00002 // for linear algebra. 00003 // 00004 // Copyright (C) 2012 Désiré Nuentsa-Wakam <desire.nuentsa_wakam@inria.fr> 00005 // 00006 // This Source Code Form is subject to the terms of the Mozilla 00007 // Public License v. 2.0. If a copy of the MPL was not distributed 00008 // with this file, You can obtain one at http://mozilla.org/MPL/2.0/. 00009 00010 /* 00011 00012 * NOTE: This file is the modified version of [s,d,c,z]column_dfs.c file in SuperLU 00013 00014 * -- SuperLU routine (version 2.0) -- 00015 * Univ. of California Berkeley, Xerox Palo Alto Research Center, 00016 * and Lawrence Berkeley National Lab. 00017 * November 15, 1997 00018 * 00019 * Copyright (c) 1994 by Xerox Corporation. All rights reserved. 00020 * 00021 * THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY 00022 * EXPRESSED OR IMPLIED. ANY USE IS AT YOUR OWN RISK. 00023 * 00024 * Permission is hereby granted to use or copy this program for any 00025 * purpose, provided the above notices are retained on all copies. 00026 * Permission to modify the code and to distribute modified code is 00027 * granted, provided the above notices are retained, and a notice that 00028 * the code was modified is included with the above copyright notice. 00029 */ 00030 #ifndef SPARSELU_COLUMN_DFS_H 00031 #define SPARSELU_COLUMN_DFS_H 00032 00033 template <typename Scalar, typename Index> class SparseLUImpl; 00034 namespace Eigen { 00035 00036 namespace internal { 00037 00038 template<typename IndexVector, typename ScalarVector> 00039 struct column_dfs_traits : no_assignment_operator 00040 { 00041 typedef typename ScalarVector::Scalar Scalar; 00042 typedef typename IndexVector::Scalar Index; 00043 column_dfs_traits(Index jcol, Index& jsuper, typename SparseLUImpl<Scalar, Index>::GlobalLU_t& glu, SparseLUImpl<Scalar, Index>& luImpl) 00044 : m_jcol(jcol), m_jsuper_ref(jsuper), m_glu(glu), m_luImpl(luImpl) 00045 {} 00046 bool update_segrep(Index /*krep*/, Index /*jj*/) 00047 { 00048 return true; 00049 } 00050 void mem_expand(IndexVector& lsub, Index& nextl, Index chmark) 00051 { 00052 if (nextl >= m_glu.nzlmax) 00053 m_luImpl.memXpand(lsub, m_glu.nzlmax, nextl, LSUB, m_glu.num_expansions); 00054 if (chmark != (m_jcol-1)) m_jsuper_ref = emptyIdxLU; 00055 } 00056 enum { ExpandMem = true }; 00057 00058 Index m_jcol; 00059 Index& m_jsuper_ref; 00060 typename SparseLUImpl<Scalar, Index>::GlobalLU_t& m_glu; 00061 SparseLUImpl<Scalar, Index>& m_luImpl; 00062 }; 00063 00064 00092 template <typename Scalar, typename Index> 00093 Index SparseLUImpl<Scalar,Index>::column_dfs(const Index m, const Index jcol, IndexVector& perm_r, Index maxsuper, Index& nseg, BlockIndexVector lsub_col, IndexVector& segrep, BlockIndexVector repfnz, IndexVector& xprune, IndexVector& marker, IndexVector& parent, IndexVector& xplore, GlobalLU_t& glu) 00094 { 00095 00096 Index jsuper = glu.supno(jcol); 00097 Index nextl = glu.xlsub(jcol); 00098 VectorBlock<IndexVector> marker2(marker, 2*m, m); 00099 00100 00101 column_dfs_traits<IndexVector, ScalarVector> traits(jcol, jsuper, glu, *this); 00102 00103 // For each nonzero in A(*,jcol) do dfs 00104 for (Index k = 0; ((k < m) ? lsub_col[k] != emptyIdxLU : false) ; k++) 00105 { 00106 Index krow = lsub_col(k); 00107 lsub_col(k) = emptyIdxLU; 00108 Index kmark = marker2(krow); 00109 00110 // krow was visited before, go to the next nonz; 00111 if (kmark == jcol) continue; 00112 00113 dfs_kernel(jcol, perm_r, nseg, glu.lsub, segrep, repfnz, xprune, marker2, parent, 00114 xplore, glu, nextl, krow, traits); 00115 } // for each nonzero ... 00116 00117 Index fsupc, jptr, jm1ptr, ito, ifrom, istop; 00118 Index nsuper = glu.supno(jcol); 00119 Index jcolp1 = jcol + 1; 00120 Index jcolm1 = jcol - 1; 00121 00122 // check to see if j belongs in the same supernode as j-1 00123 if ( jcol == 0 ) 00124 { // Do nothing for column 0 00125 nsuper = glu.supno(0) = 0 ; 00126 } 00127 else 00128 { 00129 fsupc = glu.xsup(nsuper); 00130 jptr = glu.xlsub(jcol); // Not yet compressed 00131 jm1ptr = glu.xlsub(jcolm1); 00132 00133 // Use supernodes of type T2 : see SuperLU paper 00134 if ( (nextl-jptr != jptr-jm1ptr-1) ) jsuper = emptyIdxLU; 00135 00136 // Make sure the number of columns in a supernode doesn't 00137 // exceed threshold 00138 if ( (jcol - fsupc) >= maxsuper) jsuper = emptyIdxLU; 00139 00140 /* If jcol starts a new supernode, reclaim storage space in 00141 * glu.lsub from previous supernode. Note we only store 00142 * the subscript set of the first and last columns of 00143 * a supernode. (first for num values, last for pruning) 00144 */ 00145 if (jsuper == emptyIdxLU) 00146 { // starts a new supernode 00147 if ( (fsupc < jcolm1-1) ) 00148 { // >= 3 columns in nsuper 00149 ito = glu.xlsub(fsupc+1); 00150 glu.xlsub(jcolm1) = ito; 00151 istop = ito + jptr - jm1ptr; 00152 xprune(jcolm1) = istop; // intialize xprune(jcol-1) 00153 glu.xlsub(jcol) = istop; 00154 00155 for (ifrom = jm1ptr; ifrom < nextl; ++ifrom, ++ito) 00156 glu.lsub(ito) = glu.lsub(ifrom); 00157 nextl = ito; // = istop + length(jcol) 00158 } 00159 nsuper++; 00160 glu.supno(jcol) = nsuper; 00161 } // if a new supernode 00162 } // end else: jcol > 0 00163 00164 // Tidy up the pointers before exit 00165 glu.xsup(nsuper+1) = jcolp1; 00166 glu.supno(jcolp1) = nsuper; 00167 xprune(jcol) = nextl; // Intialize upper bound for pruning 00168 glu.xlsub(jcolp1) = nextl; 00169 00170 return 0; 00171 } 00172 00173 } // end namespace internal 00174 00175 } // end namespace Eigen 00176 00177 #endif