function [ivar,vartan,options_] = get_variables_list(options_,M_)
% This function builds a vector of indices in varlist or varobs.
% 
% INPUTS 
%   o options_   [structure]  Describes global options. 
%   o M_         [structure]  Describes the model.
% OUTPUTS 
%   o ivar       [integer]    nvar*1 vector of indices (nvar is the number
%                             of variables).
%   o vartan     [char]       array of characters (with nvar rows).
%   o options_   [structure]  Describes global options.
% 
% ALGORITHM 
%   None.       
%
% SPECIAL REQUIREMENTS
%   None.

% Copyright (C) 2007-2012 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 <http://www.gnu.org/licenses/>.

varlist = options_.varlist;
if isempty(varlist)
    varlist = char(options_.varobs);
    options_.varlist = varlist;
end
nvar = rows(varlist);
vartan = varlist;
nvar = size(vartan,1);
ivar = zeros(nvar,1);
for i = 1:nvar
    ivar(i) = strmatch(deblank(vartan(i,:)),M_.endo_names,'exact');
end