1function d=jacob_element(func,element,args) 2% function d=jacob_element(func,element,args) 3% returns an entry of the finite differences approximation to the jacobian of func 4% 5% INPUTS 6% func [function name] string with name of the function 7% element [int] the index showing the element within the jacobian that should be returned 8% args [cell array] arguments provided to func 9% 10% OUTPUTS 11% d [double] jacobian[element] 12% 13% SPECIAL REQUIREMENTS 14% none 15 16% Copyright (C) 2010-2011 Dynare Team 17% 18% This file is part of Dynare. 19% 20% Dynare is free software: you can redistribute it and/or modify 21% it under the terms of the GNU General Public License as published by 22% the Free Software Foundation, either version 3 of the License, or 23% (at your option) any later version. 24% 25% Dynare is distributed in the hope that it will be useful, 26% but WITHOUT ANY WARRANTY; without even the implied warranty of 27% MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 28% GNU General Public License for more details. 29% 30% You should have received a copy of the GNU General Public License 31% along with Dynare. If not, see <http://www.gnu.org/licenses/>. 32 33func = str2func(func); 34 35h=10e-6; 36pargs=args; 37margs=args; 38% length(args) is used instead of size(args, 2) to avoid to transpose column vectors 39for i=1:length(args) 40 if i==element 41 pargs{i} = pargs{i} + h; 42 margs{i} = margs{i} - h; 43 end 44end 45d=(func(pargs{:})... 46 -func(margs{:}))/(2*h); 47