/*

Copyright (C) 1994-2017 John W. Eaton
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 (HAVE_CONFIG_H)
#  include "config.h"
#endif

#include <string>

#include "CColVector.h"
#include "CMatrix.h"
#include "aepbalance.h"
#include "dColVector.h"
#include "dMatrix.h"
#include "fCColVector.h"
#include "fCMatrix.h"
#include "fColVector.h"
#include "fMatrix.h"
#include "lo-lapack-proto.h"

static inline char
get_job (bool noperm, bool noscal)
{
  return noperm ? (noscal ? 'N' : 'S') : (noscal ? 'P' : 'B');
}

namespace octave
{
  namespace math
  {
    template <>
    aepbalance<Matrix>::aepbalance (const Matrix& a, bool noperm, bool noscal)
      : balanced_mat (a), scale (), ilo (), ihi (), job (get_job (noperm, noscal))
    {
      octave_idx_type n = a.cols ();

      if (a.rows () != n)
        (*current_liboctave_error_handler) ("aepbalance: requires square matrix");

      scale = ColumnVector (n);

      octave_idx_type info;

      F77_XFCN (dgebal, DGEBAL, (F77_CONST_CHAR_ARG2 (&job, 1), n,
                                 balanced_mat.fortran_vec (), n, ilo, ihi,
                                 scale.fortran_vec (), info
                                 F77_CHAR_ARG_LEN (1)));
    }

    template <>
    Matrix
    aepbalance<Matrix>::balancing_matrix (void) const
    {
      octave_idx_type n = balanced_mat.rows ();
      Matrix balancing_mat (n, n, 0.0);
      for (octave_idx_type i = 0; i < n; i++)
        balancing_mat.elem (i ,i) = 1.0;

      octave_idx_type info;

      char side = 'R';

      F77_XFCN (dgebak, DGEBAK, (F77_CONST_CHAR_ARG2 (&job, 1),
                                 F77_CONST_CHAR_ARG2 (&side, 1),
                                 n, ilo, ihi, scale.data (), n,
                                 balancing_mat.fortran_vec (), n, info
                                 F77_CHAR_ARG_LEN (1)
                                 F77_CHAR_ARG_LEN (1)));

      return balancing_mat;
    }

    template <>
    aepbalance<FloatMatrix>::aepbalance (const FloatMatrix& a, bool noperm,
                                         bool noscal)
      : balanced_mat (a), scale (), ilo (), ihi (), job (get_job (noperm, noscal))
    {
      octave_idx_type n = a.cols ();

      if (a.rows () != n)
        (*current_liboctave_error_handler) ("aepbalance: requires square matrix");

      scale = FloatColumnVector (n);

      octave_idx_type info;

      F77_XFCN (sgebal, SGEBAL, (F77_CONST_CHAR_ARG2 (&job, 1), n,
                                 balanced_mat.fortran_vec (), n, ilo, ihi,
                                 scale.fortran_vec (), info
                                 F77_CHAR_ARG_LEN (1)));
    }

    template <>
    FloatMatrix
    aepbalance<FloatMatrix>::balancing_matrix (void) const
    {
      octave_idx_type n = balanced_mat.rows ();
      FloatMatrix balancing_mat (n, n, 0.0);
      for (octave_idx_type i = 0; i < n; i++)
        balancing_mat.elem (i ,i) = 1.0;

      octave_idx_type info;

      char side = 'R';

      F77_XFCN (sgebak, SGEBAK, (F77_CONST_CHAR_ARG2 (&job, 1),
                                 F77_CONST_CHAR_ARG2 (&side, 1),
                                 n, ilo, ihi, scale.data (), n,
                                 balancing_mat.fortran_vec (), n, info
                                 F77_CHAR_ARG_LEN (1)
                                 F77_CHAR_ARG_LEN (1)));

      return balancing_mat;
    }

    template <>
    aepbalance<ComplexMatrix>::aepbalance (const ComplexMatrix& a, bool noperm,
                                           bool noscal)
      : balanced_mat (a), scale (), ilo (), ihi (), job (get_job (noperm, noscal))
    {
      octave_idx_type n = a.cols ();

      if (a.rows () != n)
        (*current_liboctave_error_handler) ("aepbalance: requires square matrix");

      scale = ColumnVector (n);

      octave_idx_type info;

      F77_XFCN (zgebal, ZGEBAL, (F77_CONST_CHAR_ARG2 (&job, 1), n,
                                 F77_DBLE_CMPLX_ARG (balanced_mat.fortran_vec ()), n, ilo, ihi,
                                 scale.fortran_vec (), info
                                 F77_CHAR_ARG_LEN (1)));
    }

    template <>
    ComplexMatrix
    aepbalance<ComplexMatrix>::balancing_matrix (void) const
    {
      octave_idx_type n = balanced_mat.rows ();
      ComplexMatrix balancing_mat (n, n, 0.0);
      for (octave_idx_type i = 0; i < n; i++)
        balancing_mat.elem (i, i) = 1.0;

      octave_idx_type info;

      char side = 'R';

      F77_XFCN (zgebak, ZGEBAK, (F77_CONST_CHAR_ARG2 (&job, 1),
                                 F77_CONST_CHAR_ARG2 (&side, 1),
                                 n, ilo, ihi, scale.data (), n,
                                 F77_DBLE_CMPLX_ARG (balancing_mat.fortran_vec ()), n, info
                                 F77_CHAR_ARG_LEN (1)
                                 F77_CHAR_ARG_LEN (1)));

      return balancing_mat;
    }

    template <>
    aepbalance<FloatComplexMatrix>::aepbalance (const FloatComplexMatrix& a,
                                                bool noperm, bool noscal)
      : balanced_mat (a), scale (), ilo (), ihi (), job (get_job (noperm, noscal))
    {
      octave_idx_type n = a.cols ();

      if (a.rows () != n)
        (*current_liboctave_error_handler) ("aepbalance: requires square matrix");

      scale = FloatColumnVector (n);

      octave_idx_type info;

      F77_XFCN (cgebal, CGEBAL, (F77_CONST_CHAR_ARG2 (&job, 1), n,
                                 F77_CMPLX_ARG (balanced_mat.fortran_vec ()), n, ilo, ihi,
                                 scale.fortran_vec (), info
                                 F77_CHAR_ARG_LEN (1)));
    }

    template <>
    FloatComplexMatrix
    aepbalance<FloatComplexMatrix>::balancing_matrix (void) const
    {
      octave_idx_type n = balanced_mat.rows ();
      FloatComplexMatrix balancing_mat (n, n, 0.0);
      for (octave_idx_type i = 0; i < n; i++)
        balancing_mat.elem (i, i) = 1.0;

      octave_idx_type info;

      char side = 'R';

      F77_XFCN (cgebak, CGEBAK, (F77_CONST_CHAR_ARG2 (&job, 1),
                                 F77_CONST_CHAR_ARG2 (&side, 1),
                                 n, ilo, ihi, scale.data (), n,
                                 F77_CMPLX_ARG (balancing_mat.fortran_vec ()), n, info
                                 F77_CHAR_ARG_LEN (1)
                                 F77_CHAR_ARG_LEN (1)));

      return balancing_mat;
    }

    // Instantiations we need.

    template class aepbalance<Matrix>;

    template class aepbalance<FloatMatrix>;

    template class aepbalance<ComplexMatrix>;

    template class aepbalance<FloatComplexMatrix>;
  }
}