diff options
Diffstat (limited to 'third_party/eigen3/Eigen/src/SparseLU/SparseLU_pruneL.h')
| -rw-r--r-- | third_party/eigen3/Eigen/src/SparseLU/SparseLU_pruneL.h | 135 |
1 files changed, 135 insertions, 0 deletions
diff --git a/third_party/eigen3/Eigen/src/SparseLU/SparseLU_pruneL.h b/third_party/eigen3/Eigen/src/SparseLU/SparseLU_pruneL.h new file mode 100644 index 0000000000..66460d1688 --- /dev/null +++ b/third_party/eigen3/Eigen/src/SparseLU/SparseLU_pruneL.h @@ -0,0 +1,135 @@ +// This file is part of Eigen, a lightweight C++ template library +// for linear algebra. +// +// Copyright (C) 2012 Désiré Nuentsa-Wakam <desire.nuentsa_wakam@inria.fr> +// +// This Source Code Form is subject to the terms of the Mozilla +// Public License v. 2.0. If a copy of the MPL was not distributed +// with this file, You can obtain one at http://mozilla.org/MPL/2.0/. + +/* + + * NOTE: This file is the modified version of [s,d,c,z]pruneL.c file in SuperLU + + * -- SuperLU routine (version 2.0) -- + * Univ. of California Berkeley, Xerox Palo Alto Research Center, + * and Lawrence Berkeley National Lab. + * November 15, 1997 + * + * Copyright (c) 1994 by Xerox Corporation. All rights reserved. + * + * THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY + * EXPRESSED OR IMPLIED. ANY USE IS AT YOUR OWN RISK. + * + * Permission is hereby granted to use or copy this program for any + * purpose, provided the above notices are retained on all copies. + * Permission to modify the code and to distribute modified code is + * granted, provided the above notices are retained, and a notice that + * the code was modified is included with the above copyright notice. + */ +#ifndef SPARSELU_PRUNEL_H +#define SPARSELU_PRUNEL_H + +namespace Eigen { +namespace internal { + +/** + * \brief Prunes the L-structure. + * + * It prunes the L-structure of supernodes whose L-structure contains the current pivot row "pivrow" + * + * + * \param jcol The current column of L + * \param[in] perm_r Row permutation + * \param[out] pivrow The pivot row + * \param nseg Number of segments + * \param segrep + * \param repfnz + * \param[out] xprune + * \param glu Global LU data + * + */ +template <typename Scalar, typename Index> +void SparseLUImpl<Scalar,Index>::pruneL(const Index jcol, const IndexVector& perm_r, const Index pivrow, const Index nseg, const IndexVector& segrep, BlockIndexVector repfnz, IndexVector& xprune, GlobalLU_t& glu) +{ + // For each supernode-rep irep in U(*,j] + Index jsupno = glu.supno(jcol); + Index i,irep,irep1; + bool movnum, do_prune = false; + Index kmin = 0, kmax = 0, minloc, maxloc,krow; + for (i = 0; i < nseg; i++) + { + irep = segrep(i); + irep1 = irep + 1; + do_prune = false; + + // Don't prune with a zero U-segment + if (repfnz(irep) == emptyIdxLU) continue; + + // If a snode overlaps with the next panel, then the U-segment + // is fragmented into two parts -- irep and irep1. We should let + // pruning occur at the rep-column in irep1s snode. + if (glu.supno(irep) == glu.supno(irep1) ) continue; // don't prune + + // If it has not been pruned & it has a nonz in row L(pivrow,i) + if (glu.supno(irep) != jsupno ) + { + if ( xprune (irep) >= glu.xlsub(irep1) ) + { + kmin = glu.xlsub(irep); + kmax = glu.xlsub(irep1) - 1; + for (krow = kmin; krow <= kmax; krow++) + { + if (glu.lsub(krow) == pivrow) + { + do_prune = true; + break; + } + } + } + + if (do_prune) + { + // do a quicksort-type partition + // movnum=true means that the num values have to be exchanged + movnum = false; + if (irep == glu.xsup(glu.supno(irep)) ) // Snode of size 1 + movnum = true; + + while (kmin <= kmax) + { + if (perm_r(glu.lsub(kmax)) == emptyIdxLU) + kmax--; + else if ( perm_r(glu.lsub(kmin)) != emptyIdxLU) + kmin++; + else + { + // kmin below pivrow (not yet pivoted), and kmax + // above pivrow: interchange the two suscripts + std::swap(glu.lsub(kmin), glu.lsub(kmax)); + + // If the supernode has only one column, then we + // only keep one set of subscripts. For any subscript + // intercnahge performed, similar interchange must be + // done on the numerical values. + if (movnum) + { + minloc = glu.xlusup(irep) + ( kmin - glu.xlsub(irep) ); + maxloc = glu.xlusup(irep) + ( kmax - glu.xlsub(irep) ); + std::swap(glu.lusup(minloc), glu.lusup(maxloc)); + } + kmin++; + kmax--; + } + } // end while + + xprune(irep) = kmin; //Pruning + } // end if do_prune + } // end pruning + } // End for each U-segment +} + +} // end namespace internal +} // end namespace Eigen + +#endif // SPARSELU_PRUNEL_H |