dynare_solve.m

function [x,info] = dynare_solve(func,x,options,varargin)
% function [x,info] = dynare_solve(func,x,options,varargin)
% proposes different solvers
%
% INPUTS
%    func:             name of the function to be solved
%    x:                guess values
%    options:          struct of Dynare options
%    varargin:         list of arguments following jacobian_flag
%
% OUTPUTS
%    x:                solution
%    info=1:           the model can not be solved
%
% SPECIAL REQUIREMENTS
%    none

% Copyright (C) 2001-2015 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/>.

% jacobian_flag=1:  jacobian given by the 'func' function
% jacobian_flag=0:  jacobian obtained numerically
jacobian_flag = options.jacobian_flag;

% Set tolerance parameter depending the the caller function.
stack = dbstack;
if strcmp(stack(2).file,'simulation_core.m')
    tolf = options.dynatol.f;
else
    tolf = options.solve_tolf;
end

info = 0;
nn = size(x,1);

% checking initial values
if jacobian_flag
    [fvec,fjac] = feval(func,x,varargin{:});
    if any(any(isinf(fjac) | isnan(fjac)))
        [infrow,infcol]=find(isinf(fjac) | isnan(fjac));
        M=evalin('base','M_'); %get variable names from workspace
        fprintf('\nSTEADY:  The Jacobian contains Inf or NaN. The problem arises from: \n\n')
        display_problematic_vars_Jacobian(infrow,infcol,M,x,'static','STEADY: ')
        error('An element of the Jacobian is not finite or NaN')
    end
else
    fvec = feval(func,x,varargin{:});
    fjac = zeros(nn,nn) ;
end

i = find(~isfinite(fvec));

if ~isempty(i)
    disp(['STEADY:  numerical initial values or parameters incompatible with the following' ...
          ' equations'])
    disp(i')