dynare/matlab/perfect-foresight-models/sim1_lbj.m

137 lines
4.3 KiB
Matlab

function [endogenousvariables, info] = sim1_lbj(endogenousvariables, exogenousvariables, steadystate, M, options)
% Performs deterministic simulations with lead or lag on one period using the historical LBJ algorithm
%
% INPUTS
% ...
% OUTPUTS
% ...
% ALGORITHM
% Laffargue, Boucekkine, Juillard (LBJ)
% see Juillard (1996) Dynare: A program for the resolution and
% simulation of dynamic models with forward variables through the use
% of a relaxation algorithm. CEPREMAP. Couverture Orange. 9602.
%
% SPECIAL REQUIREMENTS
% None.
% Copyright © 1996-2022 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 <https://www.gnu.org/licenses/>.
lead_lag_incidence = M.lead_lag_incidence;
ny = size(endogenousvariables,1);
nyp = nnz(lead_lag_incidence(1,:));
nyf = nnz(lead_lag_incidence(3,:));
nrs = ny+nyp+nyf+1;
nrc = nyf+1;
iyf = find(lead_lag_incidence(3,:)>0);
iyp = find(lead_lag_incidence(1,:)>0);
isp = [1:nyp];
is = [nyp+1:ny+nyp];
isf = iyf+nyp;
isf1 = [nyp+ny+1:nyf+nyp+ny+1];
stop = false;
iz = [1:ny+nyp+nyf];
dynamicmodel = sprintf('%s.dynamic', M.fname);
verbose = options.verbosity;
if verbose
printline(56)
disp(['MODEL SIMULATION :'])
skipline()
end
it_init = M.maximum_lag+1;
h1 = clock;
for iter = 1:options.simul.maxit
h2 = clock;
if ~options.terminal_condition
c = zeros(ny*options.periods, nrc);
else
c = zeros(ny*(options.periods+1), nrc);
end
it_ = it_init;
z = [endogenousvariables(iyp,it_-1) ; endogenousvariables(:,it_) ; endogenousvariables(iyf,it_+1)];
[d1, jacobian] = feval(dynamicmodel, z, exogenousvariables, M.params, steadystate, it_);
jacobian = [jacobian(:,iz), -d1];
ic = [1:ny];
icp = iyp;
c (ic,:) = jacobian(:,is)\jacobian(:,isf1);
for it_ = it_init+(1:options.periods-1)
z = [endogenousvariables(iyp,it_-1) ; endogenousvariables(:,it_) ; endogenousvariables(iyf,it_+1)];
[d1, jacobian] = feval(dynamicmodel, z, exogenousvariables, M.params, steadystate, it_);
jacobian = [jacobian(:,iz), -d1];
jacobian(:,[isf nrs]) = jacobian(:,[isf nrs])-jacobian(:,isp)*c(icp,:);
ic = ic + ny;
icp = icp + ny;
c (ic,:) = jacobian(:,is)\jacobian(:,isf1);
end
if options.terminal_condition == 1
s = eye(ny);
s(:,isf) = s(:,isf)+c(ic,1:nyf);
ic = ic + ny;
c(ic,nrc) = s\c(ic,nrc);
c = bksup1(c, ny, nrc, iyf, options.periods);
c = reshape(c, ny, options.periods+1);
endogenousvariables(:,it_init+(0:options.periods)) = endogenousvariables(:,it_init+(0:options.periods))+c;
else
c = bksup1(c, ny, nrc, iyf, options.periods);
c = reshape(c, ny, options.periods);
endogenousvariables(:,it_init+(0:options.periods-1)) = endogenousvariables(:,it_init+(0:options.periods-1))+c;
end
err = max(max(abs(c./options.scalv')));
if verbose
str = sprintf('Iter: %s,\t err. = %s, \t time = %s', num2str(iter), num2str(err), num2str(etime(clock, h2)));
disp(str);
end
if err < options.dynatol.f
stop = true;
if verbose
skipline()
disp(sprintf('Total time of simulation: %s', num2str(etime(clock,h1))))
end
info.status = 1;% Convergency obtained.
info.error = err;
info.iterations = iter;
break
end
end
if ~stop
if verbose
disp(sprintf('Total time of simulation: %s.', num2str(etime(clock,h1))))
disp('Maximum number of iterations is reached (modify option maxit).')
end
info.status = 0;% more iterations are needed.
info.error = err;
info.errors = c/abs(err);
info.iterations = options.simul.maxit;
end
if verbose
if stop
printline(56)
else
printline(62)
end
skipline()
end