function [flag,endo_simul,err] = solve_stochastic_perfect_foresight_model(endo_simul,exo_simul,pfm,nnodes) flag = 0; err = 0; stop = 0; number_of_shocks = size(exo_simul,2); [nodes,weights] = gauss_hermite_weights_and_nodes(nnodes); if number_of_shocks>1 for i=1:number_of_shocks rr(i) = {nodes}; ww(i) = {weights}; end nodes = cartesian_product_of_sets(rr{:}); weights = prod(cartesian_product_of_sets(ww{:}),2); end innovations = zeros(pfm.periods+2,number_of_shocks); model_dynamic = pfm.dynamic_model; dimension = (2+pfm.periods)*pfm.ny; % First n are given, dimension-n is the number of unknowns. Y = repmat(endo_simul(:),dimension/pfm.ny,1); if pfm.verbose disp ([' -----------------------------------------------------']); disp (['MODEL SIMULATION :']); fprintf('\n'); end z = Y(find(pfm.lead_lag_incidence')); [d1,jacobian] = model_dynamic(z,exo_simul,pfm.params,pfm.steady_state,2); A = sparse([],[],[],dimension,dimension,dimension/pfm.ny*nnz(jacobian)); res = zeros(dimension,1); h1 = clock; for iter = 1:pfm.maxit_ h2 = clock; i_rows = 1:pfm.ny; i_cols = find(pfm.lead_lag_incidence'); i_cols_p = i_cols(1:pfm.nyp); i_cols_s = i_cols(pfm.nyp+1:pfm.nyp+pfm.ny); i_cols_f = bsxfun(@plus,i_cols(pfm.nyp+pfm.ny+1:pfm.nyp+pfm.ny+pfm.nyf),pfm.ny*(0:nnodes-1)); i_cols_A = i_cols; for it = 2:(pfm.periods+1) if it == 2 y = Y(i_cols); expectations = zeros(pfm.nyf,1); for n=1:nnodes expectations = expectations+weights(n)*Y(i_cols_f(:,n)); end y(it*pfm.ny+pfm.iyf) = expectations; [d1,jacobian] = model_dynamic(y,exo_simul,pfm.params,pfm.steady_state,it); A(i_rows,pfm.i_cols_A1) = jacobian(:,pfm.i_cols_1); i_rows = i_rows + pfm.ny; i_cols_p = bsxfun(@plus,i_cols_p,repmat(pfm.ny,1,nnodes)); i_cols_s = bsxfun(@plus,i_cols_s,pfm.ny*(1:nnodes)); i_cols_f = bsxfun(@plus,i_cols_f,pfm.ny*nnodes); elseif it == pfm.periods+1 A(i_rows,i_cols_A(pfm.i_cols_T)) = jacobian(:,pfm.i_cols_T); else for n=1:nnodes innovations(3,:) = nodes(n,:); i_cols = [i_cols_p(:,n); i_cols_s(:,n); i_cols_f(:,n)]; [d1,jacobian] = model_dynamic(Y(i_cols),innovations,pfm.params,pfm.steady_state,it); A(i_rows,i_cols_A) = jacobian(:,pfm.i_cols_j); end i_cols_s = i_cols_s + pfm.ny*nnodes; i_cols_f = i_cols_f + pfm.ny*nnodes; if it == 3 i_cols_p = bsxfun(@plus,i_cols_p,pfm.ny*(1:nnodes)); else i_cols_p = i_cols_p + pfm.ny*nnodes; end end res(i_rows) = d1; %i_rows = i_rows + pfm.ny; %i_cols = i_cols + pfm.ny; if it > 2 i_cols_A = i_cols_A + pfm.ny; end end err = max(abs(res)); if err < pfm.tolerance stop = 1 ; if pfm.verbose fprintf('\n') ; disp([' Total time of simulation :' num2str(etime(clock,h1))]) ; fprintf('\n') ; disp([' Convergency obtained.']) ; fprintf('\n') ; end flag = 0;% Convergency obtained. endo_simul = reshape(Y,pfm.ny,pfm.periods+2); break end dy = -A\res; Y(pfm.i_upd) = Y(pfm.i_upd) + dy; end if ~stop if pfm.verbose fprintf('\n') ; disp([' Total time of simulation :' num2str(etime(clock,h1))]) ; fprintf('\n') ; disp(['WARNING : maximum number of iterations is reached (modify options_.maxit_).']) ; fprintf('\n') ; end flag = 1;% more iterations are needed. endo_simul = 1; end if pfm.verbose disp (['-----------------------------------------------------']) ; end