1function g4_unfolded = unfold_g4(g4, ny) 2% Given the 4th order derivatives stored in a sparse matrix and without 3% symmetric elements (as returned by the static/dynamic files) and the number 4% of (static or dynamic) variables in the jacobian, returns 5% an unfolded version of the same matrix (i.e. with symmetric elements). 6 7% Copyright (C) 2019 Dynare Team 8% 9% This file is part of Dynare. 10% 11% Dynare is free software: you can redistribute it and/or modify 12% it under the terms of the GNU General Public License as published by 13% the Free Software Foundation, either version 3 of the License, or 14% (at your option) any later version. 15% 16% Dynare is distributed in the hope that it will be useful, 17% but WITHOUT ANY WARRANTY; without even the implied warranty of 18% MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 19% GNU General Public License for more details. 20% 21% You should have received a copy of the GNU General Public License 22% along with Dynare. If not, see <http://www.gnu.org/licenses/>. 23 24[i, j, v] = find(g4); 25 26i_unfolded = []; 27j_unfolded = []; 28v_unfolded = []; 29 30for k = 1:length(v) 31 l1 = rem(j(k)-1, ny); 32 j2 = floor((j(k)-1)/ny); 33 l2 = rem(j2, ny); 34 j3 = floor((j(k)-1)/ny^2); 35 l3 = rem(j3,ny); 36 l4 = floor(j3/ny); 37 38 p = unique(perms([l1 l2 l3 l4]), 'rows'); 39 np = rows(p); 40 41 i_unfolded = [i_unfolded; repmat(i(k), np, 1)]; 42 j_unfolded = [j_unfolded; 1 + p(:,1) + ny*(p(:,2) + ny*(p(:,3) + ny*p(:,4)))]; 43 v_unfolded = [v_unfolded; repmat(v(k), np, 1)]; 44end 45 46g4_unfolded = sparse(i_unfolded, j_unfolded, v_unfolded, size(g4, 1), size(g4, 2)); 47