view liboctave/base-aepbal.h @ 8987:542015fada9e

Eliminate the workspace in sparse transpose. The output's cidx (column start offset array) can serve as the workspace, so the routines operate in the space of their output.
author Jason Riedy <jason@acm.org>
date Mon, 16 Mar 2009 17:03:07 -0400
parents a5e080076778
children 7319e4de9e44
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/*

Copyright (C) 2008 Jaroslav Hajek

This file is part of Octave.

Octave is free software; 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 3 of the License, or (at your
option) any later version.

Octave 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 General Public License
for more details.

You should have received a copy of the GNU General Public License
along with Octave; see the file COPYING.  If not, see
<http://www.gnu.org/licenses/>.

*/

#if !defined (octave_base_aepbal_h)
#define octave_base_aepbal_h 1

#include "oct-types.h"

template <class MatrixT, class VectorT>
class base_aepbal
{
protected:
  MatrixT balanced_mat;
  VectorT scale;
  octave_idx_type ilo, ihi;
  char job;
  base_aepbal (void) : balanced_mat (), scale (), ilo (), ihi (), job () { }

public:

  base_aepbal (const base_aepbal& a) 
    : balanced_mat (a.balanced_mat), scale (a.scale), 
      ilo(a.ilo), ihi(a.ihi), job(a.job)
  { 
  }

  base_aepbal& operator = (const base_aepbal& a)
    {
      balanced_mat = a.balanced_mat;
      scale = a.scale;
      ilo = a.ilo;
      ihi = a.ihi;
      job = a.job;
    }

  MatrixT balanced_matrix (void) const { return balanced_mat; }

  VectorT permuting_vector (void) const
    {
      octave_idx_type n = balanced_mat.rows ();
      VectorT pv (n);
      for (octave_idx_type i = 0; i < n; i++)
        pv(i) = i+1;
      for (octave_idx_type i = n-1; i >= ihi; i--)
        {
          octave_idx_type j = scale(i) - 1;
          octave_idx_type k = pv(j);
          pv(j) = pv(i);
          pv(i) = k;
        }
      for (octave_idx_type i = ilo-2; i >= 0; i--)
        {
          octave_idx_type j = scale(i) - 1;
          octave_idx_type k = pv(j);
          pv(j) = pv(i);
          pv(i) = k;
        }
      
      return pv;
    }

  VectorT scaling_vector (void) const
    {
      octave_idx_type n = balanced_mat.rows ();
      VectorT scv (n);
      for (octave_idx_type i = 0; i < ilo-1; i++)
        scv(i) = 1;
      for (octave_idx_type i = ilo-1; i < ihi; i++)
        scv(i) = scale(i);
      for (octave_idx_type i = ihi; i < n; i++)
        scv(i) = 1;

      return scv;
    }
};

#endif