// Template array classes
/*

Copyright (C) 1996-2011 John W. Eaton
Copyright (C) 2010 VZLU Prague

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 <cassert>

#include <iostream>

#include <algorithm>

#include "DiagArray2.h"

#include "lo-error.h"

template <class T>
DiagArray2<T>::DiagArray2 (const Array<T>& a, octave_idx_type r, octave_idx_type c)
  : Array<T> (a.as_column ()), d1 (r), d2 (c)
{
  octave_idx_type rcmin = std::min (r, c);
  if (rcmin != a.length ())
      Array<T>::resize (rcmin, 1);
}

template <class T>
Array<T>
DiagArray2<T>::diag (octave_idx_type k) const
{
  Array<T> d;

  if (k == 0)
    // The main diagonal is shallow-copied.
    d = *this;
  else if (k > 0 && k < cols ())
    d = Array<T> (std::min (cols () - k, rows ()), 1, T ());
  else if (k < 0 && -k < rows ())
    d = Array<T> (std::min (rows () + k, cols ()), 1, T ());
  else
    (*current_liboctave_error_handler)
      ("diag: requested diagonal out of range");

  return d;
}

template <class T>
DiagArray2<T>
DiagArray2<T>::transpose (void) const
{
  return DiagArray2<T> (*this, d2, d1);
}

template <class T>
DiagArray2<T>
DiagArray2<T>::hermitian (T (* fcn) (const T&)) const
{
  return DiagArray2<T> (Array<T>::template map<T> (fcn), d2, d1);
}

// A two-dimensional array with diagonal elements only.

template <class T>
T
DiagArray2<T>::checkelem (octave_idx_type r, octave_idx_type c) const
{
  if (r < 0 || r >= dim1 ())
    gripe_index_out_of_range (2, 1, r+1, dim1 ());
  if (c < 0 || c >= dim2 ())
    gripe_index_out_of_range (2, 2, c+1, dim2 ());

  return elem (r, c);
}

template <class T>
void
DiagArray2<T>::resize (octave_idx_type r, octave_idx_type c,
                       const T& rfv)
{
  if (r < 0 || c < 0)
    {
      (*current_liboctave_error_handler) ("can't resize to negative dimensions");
      return;
    }

  if (r != dim1 () || c != dim2 ())
    {
      Array<T>::resize (std::min (r, c), 1, rfv);
      d1 = r; d2 = c;
    }
}

template <class T>
Array<T> DiagArray2<T>::array_value (void) const
{
  Array<T> result (dim1 (), dim2 ());
  for (octave_idx_type i = 0, len = length (); i < len; i++)
    result.xelem (i, i) = dgelem (i);

  return result;
}