/*

Copyright (C) 1994, 1995, 1996, 1997, 1999, 2002, 2003, 2004, 2005,
              2007, 2008 John W. Eaton
Copyright (C) 2009 VZLU Prague, a.s.

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/>.

*/

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include "dbleLU.h"
#include "f77-fcn.h"
#include "lo-error.h"
#include "oct-locbuf.h"
#include "dColVector.h"

// Instantiate the base LU class for the types we need.

#include <base-lu.h>
#include <base-lu.cc>

template class base_lu <Matrix>;

// Define the constructor for this particular derivation.

extern "C"
{
  F77_RET_T
  F77_FUNC (dgetrf, DGETRF) (const octave_idx_type&, const octave_idx_type&,
                             double*, const octave_idx_type&,
                             octave_idx_type*, octave_idx_type&);

#ifdef HAVE_QRUPDATE_LUU
  F77_RET_T
  F77_FUNC (dlu1up, DLU1UP) (const octave_idx_type&, const octave_idx_type&,
                             double *, const octave_idx_type&,
                             double *, const octave_idx_type&,
                             double *, double *);

  F77_RET_T
  F77_FUNC (dlup1up, DLUP1UP) (const octave_idx_type&, const octave_idx_type&,
                               double *, const octave_idx_type&,
                               double *, const octave_idx_type&,
                               octave_idx_type *, const double *,
                               const double *, double *);
#endif
}

LU::LU (const Matrix& a)
{
  octave_idx_type a_nr = a.rows ();
  octave_idx_type a_nc = a.cols ();
  octave_idx_type mn = (a_nr < a_nc ? a_nr : a_nc);

  ipvt.resize (mn, 1);
  octave_idx_type *pipvt = ipvt.fortran_vec ();

  a_fact = a;
  double *tmp_data = a_fact.fortran_vec ();

  octave_idx_type info = 0;

  F77_XFCN (dgetrf, DGETRF, (a_nr, a_nc, tmp_data, a_nr, pipvt, info));

  for (octave_idx_type i = 0; i < mn; i++)
    pipvt[i] -= 1;
}

#ifdef HAVE_QRUPDATE_LUU

void LU::update (const ColumnVector& u, const ColumnVector& v)
{
  if (packed ())
    unpack ();

  Matrix& l = l_fact;
  Matrix& r = a_fact;

  octave_idx_type m = l.rows ();
  octave_idx_type n = r.columns ();
  octave_idx_type k = l.columns ();

  if (u.length () == m && v.length () == n)
    {
      ColumnVector utmp = u, vtmp = v;
      F77_XFCN (dlu1up, DLU1UP, (m, n, l.fortran_vec (), m, r.fortran_vec (), k,
                                 utmp.fortran_vec (), vtmp.fortran_vec ()));
    }
  else
    (*current_liboctave_error_handler) ("luupdate: dimensions mismatch");
}

void LU::update (const Matrix& u, const Matrix& v)
{
  if (packed ())
    unpack ();

  Matrix& l = l_fact;
  Matrix& r = a_fact;

  octave_idx_type m = l.rows ();
  octave_idx_type n = r.columns ();
  octave_idx_type k = l.columns ();

  if (u.rows () == m && v.rows () == n && u.cols () == v.cols ())
    {
      for (volatile octave_idx_type i = 0; i < u.cols (); i++)
        {
          ColumnVector utmp = u.column (i), vtmp = v.column (i);
          F77_XFCN (dlu1up, DLU1UP, (m, n, l.fortran_vec (), m, r.fortran_vec (), k,
                                     utmp.fortran_vec (), vtmp.fortran_vec ()));
        }
    }
  else
    (*current_liboctave_error_handler) ("luupdate: dimensions mismatch");
}

void LU::update_piv (const ColumnVector& u, const ColumnVector& v)
{
  if (packed ())
    unpack ();

  Matrix& l = l_fact;
  Matrix& r = a_fact;

  octave_idx_type m = l.rows ();
  octave_idx_type n = r.columns ();
  octave_idx_type k = l.columns ();

  if (u.length () == m && v.length () == n)
    {
      ColumnVector utmp = u, vtmp = v;
      OCTAVE_LOCAL_BUFFER (double, w, m);
      for (octave_idx_type i = 0; i < m; i++) ipvt(i) += 1; // increment
      F77_XFCN (dlup1up, DLUP1UP, (m, n, l.fortran_vec (), m, r.fortran_vec (), k,
                                   ipvt.fortran_vec (), utmp.data (), vtmp.data (), w));
      for (octave_idx_type i = 0; i < m; i++) ipvt(i) -= 1; // decrement
    }
  else
    (*current_liboctave_error_handler) ("luupdate: dimensions mismatch");
}

void LU::update_piv (const Matrix& u, const Matrix& v)
{
  if (packed ())
    unpack ();

  Matrix& l = l_fact;
  Matrix& r = a_fact;

  octave_idx_type m = l.rows ();
  octave_idx_type n = r.columns ();
  octave_idx_type k = l.columns ();

  if (u.rows () == m && v.rows () == n && u.cols () == v.cols ())
    {
      OCTAVE_LOCAL_BUFFER (double, w, m);
      for (octave_idx_type i = 0; i < m; i++) ipvt(i) += 1; // increment
      for (volatile octave_idx_type i = 0; i < u.cols (); i++)
        {
          ColumnVector utmp = u.column (i), vtmp = v.column (i);
          F77_XFCN (dlup1up, DLUP1UP, (m, n, l.fortran_vec (), m, r.fortran_vec (), k,
                                       ipvt.fortran_vec (), utmp.data (), vtmp.data (), w));
        }
      for (octave_idx_type i = 0; i < m; i++) ipvt(i) -= 1; // decrement
    }
  else
    (*current_liboctave_error_handler) ("luupdate: dimensions mismatch");
}

#else

void LU::update (const ColumnVector&, const ColumnVector&)
{
  (*current_liboctave_error_handler) ("luupdate: not available in this version");
}

void LU::update (const Matrix&, const Matrix&)
{
  (*current_liboctave_error_handler) ("luupdate: not available in this version");
}

void LU::update_piv (const ColumnVector&, const ColumnVector&)
{
  (*current_liboctave_error_handler) ("luupdate: not available in this version");
}

void LU::update_piv (const Matrix&, const Matrix&)
{
  (*current_liboctave_error_handler) ("luupdate: not available in this version");
}

#endif