/*

Copyright (C) 2009-2016   Lukas F. Reichlin

This file is part of LTI Syncope.

LTI Syncope 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.

LTI Syncope 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 LTI Syncope.  If not, see <http://www.gnu.org/licenses/>.

Return true if all arguments are real-valued, square matrices and false otherwise.

Author: Lukas Reichlin <lukas.reichlin@gmail.com>
Created: September 2010
Version: 0.2

*/

#include <octave/oct.h>
#include "config.h"

// PKG_ADD: autoload ("is_real_square_matrix", "__control_helper_functions__.oct");    
DEFUN_DLD (is_real_square_matrix, args, nargout,
   "-*- texinfo -*-\n"
   "@deftypefn {Loadable Function} {} is_real_square_matrix (@var{a}, @dots{})@*\n"
   "Return true if all arguments are real-valued, square matrices and false otherwise.@*\n"
   "@var{[]} is a valid square matrix.@*\n"
   "Avoid nasty stuff like @code{true = isreal (\"a\")}@*\n"
   "@seealso{is_real_matrix, is_real_vector, is_real_scalar}@*\n"
   "@end deftypefn")
{
    octave_value retval = true;
    octave_idx_type nargin = args.length ();

    if (nargin == 0)
    {
        print_usage ();
    }
    else
    {
        for (octave_idx_type i = 0; i < nargin; i++)
        {
            if (args(i).ndims () != 2 || args(i).rows () != args(i).columns ()
                || ! args(i).isnumeric () || ! args(i).isreal ())
            {
                retval = false;
                break;
            }
        }
    }

    return retval;
}
