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 
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 Index>
copy_to_ucol(const Index jcol,const Index nseg,IndexVector & segrep,BlockIndexVector repfnz,IndexVector & perm_r,BlockScalarVector dense,GlobalLU_t & glu)50 Index 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