function [errorcode, varargout] = common_size (varargin)
% COMMON_SIZE  Checks that all inputs are either scalar or of common size
%  [ERR, Y1, ...] = common_size(X1, ...)
%  Determine if all input arguments are either scalar or of common
%  size.  If so, ERR is zero, and YI is a matrix of the
%  common size with all entries equal to XI if this is a scalar or
%  XI otherwise.  If the inputs cannot be brought to a common size,
%  errorcode is 1, and YI is XI.
%
%  Example:
%   [errorcode, a, b] = common_size([1 2; 3 4], 5)
%      >> errorcode = 0
%      >> a = [ 1, 2; 3, 4 ]
%      >> b = [ 5, 5; 5, 5 ]

% Adapted from GNU Octave 3.0.1
% Original file: general/common_size.m
% Original author: KH <Kurt.Hornik@wu-wien.ac.at>

% Copyright © 1995, 1996, 1999, 2000, 2002, 2004, 2005, 2007 Kurt Hornik
% Copyright © 2008-2022 Dynare Team
%
% This file is part of Dynare.
%
% Dynare 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.
%
% Dynare 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 Dynare.  If not, see <https://www.gnu.org/licenses/>.

if (nargin < 2)
    error ('common_size: only makes sense if nargin >= 2');
end

len = 2;
for i = 1 : nargin
    sz =  size (varargin{i});
    if (length (sz) < len)
        s(i,:) = [sz, ones(1,len - length(sz))];
    else
        if (length (sz) > len)
            if (i > 1)
                s = [s, ones(size(s,1), length(sz) - len)];
            end
            len = length (sz);
        end
        s(i,:) = sz;
    end
end

m = max (s);
if (any (any ((s ~= 1)') & any ((s ~= ones (nargin, 1) * m)')))
    errorcode = 1;
    varargout = varargin;
else
    errorcode = 0;
    for i = 1 : nargin
        varargout{i} = varargin{i};
        if (prod (s(i,:)) == 1)
            varargout{i} = varargout{i} * ones (m);
        end
    end
end

end
