1// This file is part of Eigen, a lightweight C++ template library
2// for linear algebra.
3//
4// Copyright (C) 2012 Désiré Nuentsa-Wakam <desire.nuentsa_wakam@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
32namespace Eigen {
33namespace 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 */
49template <typename Scalar, typename Index>
50Index SparseLUImpl<Scalar,Index>::copy_to_ucol(const Index jcol, const Index nseg, IndexVector& segrep, BlockIndexVector repfnz ,IndexVector& perm_r, BlockScalarVector dense, GlobalLU_t& glu)
51{
52  Index ksub, krep, ksupno;
53
54  Index jsupno = glu.supno(jcol);
55
56  // For each nonzero supernode segment of U[*,j] in topological order
57  Index k = nseg - 1, i;
58  Index nextu = glu.xusub(jcol);
59  Index kfnz, isub, segsize;
60  Index new_next,irow;
61  Index fsupc, mem;
62  for (ksub = 0; ksub < nseg; ksub++)
63  {
64    krep = segrep(k); k--;
65    ksupno = glu.supno(krep);
66    if (jsupno != ksupno ) // should go into ucol();
67    {
68      kfnz = repfnz(krep);
69      if (kfnz != emptyIdxLU)
70      { // Nonzero U-segment
71        fsupc = glu.xsup(ksupno);
72        isub = glu.xlsub(fsupc) + kfnz - fsupc;
73        segsize = krep - kfnz + 1;
74        new_next = nextu + segsize;
75        while (new_next > glu.nzumax)
76        {
77          mem = memXpand<ScalarVector>(glu.ucol, glu.nzumax, nextu, UCOL, glu.num_expansions);
78          if (mem) return mem;
79          mem = memXpand<IndexVector>(glu.usub, glu.nzumax, nextu, USUB, glu.num_expansions);
80          if (mem) return mem;
81
82        }
83
84        for (i = 0; i < segsize; i++)
85        {
86          irow = glu.lsub(isub);
87          glu.usub(nextu) = perm_r(irow); // Unlike the L part, the U part is stored in its final order
88          glu.ucol(nextu) = dense(irow);
89          dense(irow) = Scalar(0.0);
90          nextu++;
91          isub++;
92        }
93
94      } // end nonzero U-segment
95
96    } // end if jsupno
97
98  } // end for each segment
99  glu.xusub(jcol + 1) = nextu; // close U(*,jcol)
100  return 0;
101}
102
103} // namespace internal
104} // end namespace Eigen
105
106#endif // SPARSELU_COPY_TO_UCOL_H
107