issquare.m

%% Copyright (C) 1996, 1997 John W. Eaton
%%
%% 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 2, 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, write to the Free
%% Software Foundation, 59 Temple Place - Suite 330, Boston, MA
%% 02111-1307, USA.

%% -*- texinfo -*-
%% @deftypefn {Function File} {} issquare (@var{x})
%% If @var{x} is a square matrix, then return the dimension of @var{x}.
%% Otherwise, return 0.
%% @end deftypefn
%% @seealso{size, rows, columns, length, ismatrix, isscalar, and isvector}

%% Author: A. S. Hodel <scotte@eng.auburn.edu>
%% Created: August 1993
%% Adapted-By: jwe

function retval = issquare (x)

  retval = 0;

  if (nargin == 1)
    if (ismatrix (x))
      [nr, nc] = size (x);
      if (nr == nc && nr > 0)
        retval = nr;
      end
    end
  else
    usage ('issquare (x)');
  end

end