Eliminate and prune columns in a panel

2026-04-10 11:34:33 +08:00 · 2012-05-31 17:10:29 +02:00
parent 8608d08d65
commit b26d6b02de
5 changed files with 412 additions and 20 deletions
--- a/Eigen/src/SparseLU/SparseLU_copy_to_ucol.h
+++ b/Eigen/src/SparseLU/SparseLU_copy_to_ucol.h
@@ -0,0 +1,123 @@
+// 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>
+//
+// Eigen is free software; you can redistribute it and/or
+// modify it under the terms of the GNU Lesser General Public
+// License as published by the Free Software Foundation; either
+// version 3 of the License, or (at your option) any later version.
+//
+// Alternatively, you can redistribute it and/or
+// modify it under the terms of the GNU General Public License as
+// published by the Free Software Foundation; either version 2 of
+// the License, or (at your option) any later version.
+//
+// Eigen is distributed in the hope that it will be useful, but WITHOUT ANY
+// WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+// FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License or the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public
+// License and a copy of the GNU General Public License along with
+// Eigen. If not, see <http://www.gnu.org/licenses/>.
+
+/* 
+ 
+ * NOTE: This file is the modified version of xcopy_to_ucol.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_COPY_TO_UCOL_H
+#define SPARSELU_COPY_TO_UCOL_H
+/**
+ * \brief Performs numeric block updates (sup-col) in topological order
+ * 
+ * \param jcol current column to update
+ * \param nseg Number of segments in the U part
+ * \param segrep segment representative ...
+ * \param repfnz ??? First nonzero column in each row ???  ...
+ * \param perm_r Row permutation 
+ * \param dense Store the full representation of the column
+ * \param Glu Global LU data. 
+ * \return 0 - successful return 
+ *         > 0 - number of bytes allocated when run out of space
+ * 
+ */
+template <typename VectorType>
+int SparseLU::LU_copy_to_ucol(const int jcol, const int nseg, VectorXi& segrep, VectorXi& repfnz, VectorXi& perm_r, VectorType& dense, LU_GlobalLu_t& Glu)
+{ 
+  int ksupno, k, ksub, krep, ksupno; 
+  
+  VectorXi& xsup = Glu.xsup; 
+  VectorXi& supno = Glu.supno; 
+  VectorXi& lsub = Glu.lsub; 
+  VectorXi& xlsub = Glu.xlsub; 
+  VectorType& ucol = GLu.ucol; 
+  VectorXi& usub = Glu.usub; 
+  VectorXi& xusub = Glu.xusub;
+  int nzumax = GLu.nzumax; 
+  int jsupno = supno(jcol);
+  
+  // For each nonzero supernode segment of U[*,j] in topological order 
+  k = nseg - 1; 
+  int nextu = xusub(jcol); 
+  int kfnz, isub, segsize; 
+  int new_next,irow; 
+  for (ksub = 0; ksub < nseg; ksub++)
+  {
+    krep = segrep(k); k--; 
+    ksupno = supno(krep); 
+    if (jsupno != ksupno ) // should go into ucol(); 
+    {
+      kfnz = repfnz(krep); 
+      if (kfnz != IND_EMPTY)
+      { // Nonzero U-segment 
+        fsupc = xsup(ksupno); 
+        isub = xlsub(fsupc) + kfnz - fsupc; 
+        segsize = krep - kfnz + 1; 
+        new_next = nextu + segsize; 
+        while (new_next > nzumax) 
+        {
+          Glu.ucol = LU_MemXpand<Scalar>(jcol, nextu, UCOL, nzumax);  //FIXME try and catch errors
+          ucol = Glu.ucol; 
+          Glu.nzumax = nzumax; 
+          Glu.usub = LU_MemXpand<Index>(jcol, nextu, USUB, nzumax); //FIXME try and catch errors 
+          Glu.nzumax = nzumax; 
+          usub = Glu.usub; 
+          lsub = Glu.lsub; 
+        }
+        
+        for (i = 0; i < segsize; i++)
+        {
+          irow = lsub(isub); 
+          usub(nextu) = perm_r(irow); // Unlike teh L part, the U part is stored in its final order
+          ucol(nextu) = dense(irow); 
+          dense(irow) = Scalar(0.0); 
+          nextu++;
+          isub++;
+        }
+        
+      } // end nonzero U-segment 
+      
+    } // end if jsupno 
+    
+  } // end for each segment
+  xusub(jcol + 1) = nextu; // close U(*,jcol)
+  return 0; 
+}
+#endif