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      1 // This file is part of Eigen, a lightweight C++ template library
      2 // for linear algebra.
      3 //
      4 // Copyright (C) 2012 Dsir Nuentsa-Wakam <desire.nuentsa_wakam (at) inria.fr>
      5 //
      6 // This Source Code Form is subject to the terms of the Mozilla
      7 // Public License v. 2.0. If a copy of the MPL was not distributed
      8 // with this file, You can obtain one at http://mozilla.org/MPL/2.0/.
      9 /*
     10 
     11  * NOTE: This file is the modified version of [s,d,c,z]copy_to_ucol.c file in SuperLU
     12 
     13  * -- SuperLU routine (version 2.0) --
     14  * Univ. of California Berkeley, Xerox Palo Alto Research Center,
     15  * and Lawrence Berkeley National Lab.
     16  * November 15, 1997
     17  *
     18  * Copyright (c) 1994 by Xerox Corporation.  All rights reserved.
     19  *
     20  * THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY
     21  * EXPRESSED OR IMPLIED.  ANY USE IS AT YOUR OWN RISK.
     22  *
     23  * Permission is hereby granted to use or copy this program for any
     24  * purpose, provided the above notices are retained on all copies.
     25  * Permission to modify the code and to distribute modified code is
     26  * granted, provided the above notices are retained, and a notice that
     27  * the code was modified is included with the above copyright notice.
     28  */
     29 #ifndef SPARSELU_COPY_TO_UCOL_H
     30 #define SPARSELU_COPY_TO_UCOL_H
     31 
     32 namespace Eigen {
     33 namespace internal {
     34 
     35 /**
     36  * \brief Performs numeric block updates (sup-col) in topological order
     37  *
     38  * \param jcol current column to update
     39  * \param nseg Number of segments in the U part
     40  * \param segrep segment representative ...
     41  * \param repfnz First nonzero column in each row  ...
     42  * \param perm_r Row permutation
     43  * \param dense Store the full representation of the column
     44  * \param glu Global LU data.
     45  * \return 0 - successful return
     46  *         > 0 - number of bytes allocated when run out of space
     47  *
     48  */
     49 template <typename Scalar, typename StorageIndex>
     50 Index SparseLUImpl<Scalar,StorageIndex>::copy_to_ucol(const Index jcol, const Index nseg, IndexVector& segrep,
     51                                                       BlockIndexVector repfnz ,IndexVector& perm_r, BlockScalarVector dense, GlobalLU_t& glu)
     52 {
     53   Index ksub, krep, ksupno;
     54 
     55   Index jsupno = glu.supno(jcol);
     56 
     57   // For each nonzero supernode segment of U[*,j] in topological order
     58   Index k = nseg - 1, i;
     59   StorageIndex nextu = glu.xusub(jcol);
     60   Index kfnz, isub, segsize;
     61   Index new_next,irow;
     62   Index fsupc, mem;
     63   for (ksub = 0; ksub < nseg; ksub++)
     64   {
     65     krep = segrep(k); k--;
     66     ksupno = glu.supno(krep);
     67     if (jsupno != ksupno ) // should go into ucol();
     68     {
     69       kfnz = repfnz(krep);
     70       if (kfnz != emptyIdxLU)
     71       { // Nonzero U-segment
     72         fsupc = glu.xsup(ksupno);
     73         isub = glu.xlsub(fsupc) + kfnz - fsupc;
     74         segsize = krep - kfnz + 1;
     75         new_next = nextu + segsize;
     76         while (new_next > glu.nzumax)
     77         {
     78           mem = memXpand<ScalarVector>(glu.ucol, glu.nzumax, nextu, UCOL, glu.num_expansions);
     79           if (mem) return mem;
     80           mem = memXpand<IndexVector>(glu.usub, glu.nzumax, nextu, USUB, glu.num_expansions);
     81           if (mem) return mem;
     82 
     83         }
     84 
     85         for (i = 0; i < segsize; i++)
     86         {
     87           irow = glu.lsub(isub);
     88           glu.usub(nextu) = perm_r(irow); // Unlike the L part, the U part is stored in its final order
     89           glu.ucol(nextu) = dense(irow);
     90           dense(irow) = Scalar(0.0);
     91           nextu++;
     92           isub++;
     93         }
     94 
     95       } // end nonzero U-segment
     96 
     97     } // end if jsupno
     98 
     99   } // end for each segment
    100   glu.xusub(jcol + 1) = nextu; // close U(*,jcol)
    101   return 0;
    102 }
    103 
    104 } // namespace internal
    105 } // end namespace Eigen
    106 
    107 #endif // SPARSELU_COPY_TO_UCOL_H
    108