dynare/matlab/perfect-foresight-models/sim1.m

333 lines
10 KiB
Matlab

function [endogenousvariables, info] = sim1(endogenousvariables, exogenousvariables, steadystate, M, options)
% Performs deterministic simulations with lead or lag on one period. Uses sparse matrices.
%
% INPUTS
% - endogenousvariables [double] N*T array, paths for the endogenous variables (initial guess).
% - exogenousvariables [double] T*M array, paths for the exogenous variables.
% - steadystate [double] N*1 array, steady state for the endogenous variables.
% - M [struct] contains a description of the model.
% - options [struct] contains various options.
% OUTPUTS
% - endogenousvariables [double] N*T array, paths for the endogenous variables (solution of the perfect foresight model).
% - info [struct] contains informations about the results.
% ALGORITHM
% ...
%
% SPECIAL REQUIREMENTS
% None.
% Copyright (C) 1996-2018 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/>.
verbose = options.verbosity;
endogenous_terminal_period = options.endogenous_terminal_period;
vperiods = options.periods*ones(1,options.simul.maxit);
azero = options.dynatol.f/1e7;
lead_lag_incidence = M.lead_lag_incidence;
ny = M.endo_nbr;
maximum_lag = M.maximum_lag;
max_lag = M.maximum_endo_lag;
nyp = nnz(lead_lag_incidence(1,:)) ;
ny0 = nnz(lead_lag_incidence(2,:)) ;
nyf = nnz(lead_lag_incidence(3,:)) ;
nd = nyp+ny0+nyf;
stop = 0 ;
periods = options.periods;
params = M.params;
i_cols_1 = nonzeros(lead_lag_incidence(2:3,:)');
i_cols_A1 = find(lead_lag_incidence(2:3,:)');
i_cols_A1 = i_cols_A1(:);
i_cols_T = nonzeros(lead_lag_incidence(1:2,:)');
i_cols_0 = nonzeros(lead_lag_incidence(2,:)');
i_cols_A0 = find(lead_lag_incidence(2,:)');
i_cols_A0 = i_cols_A0(:);
i_cols_j = (1:nd)';
i_upd = maximum_lag*ny+(1:periods*ny);
Y = endogenousvariables(:);
if verbose
skipline()
printline(56)
disp('MODEL SIMULATION:')
skipline()
end
model_dynamic = str2func([M.fname,'.dynamic']);
z = Y(find(lead_lag_incidence'));
[d1,jacobian] = model_dynamic(z, exogenousvariables, params, steadystate,maximum_lag+1);
res = zeros(periods*ny,1);
o_periods = periods;
if endogenous_terminal_period
ZERO = zeros(length(i_upd),1);
end
h1 = clock ;
iA = zeros(periods*M.NNZDerivatives(1),3);
for iter = 1:options.simul.maxit
h2 = clock ;
i_rows = (1:ny)';
i_cols_A = find(lead_lag_incidence');
i_cols_A = i_cols_A(:);
i_cols = i_cols_A+(maximum_lag-1)*ny;
m = 0;
for it = (maximum_lag+1):(maximum_lag+periods)
[d1,jacobian] = model_dynamic(Y(i_cols), exogenousvariables, params, steadystate,it);
if it == maximum_lag+periods && it == maximum_lag+1
[r,c,v] = find(jacobian(:,i_cols_0));
iA((1:length(v))+m,:) = [i_rows(r(:)),i_cols_A0(c(:)),v(:)];
elseif it == maximum_lag+periods
[r,c,v] = find(jacobian(:,i_cols_T));
iA((1:length(v))+m,:) = [i_rows(r(:)),i_cols_A(i_cols_T(c(:))),v(:)];
elseif it == maximum_lag+1
[r,c,v] = find(jacobian(:,i_cols_1));
iA((1:length(v))+m,:) = [i_rows(r(:)),i_cols_A1(c(:)),v(:)];
else
[r,c,v] = find(jacobian(:,i_cols_j));
iA((1:length(v))+m,:) = [i_rows(r(:)),i_cols_A(c(:)),v(:)];
end
m = m + length(v);
res(i_rows) = d1;
if endogenous_terminal_period && iter>1
dr = max(abs(d1));
if dr<azero
vperiods(iter) = it;
periods = it-maximum_lag+1;
break
end
end
i_rows = i_rows + ny;
i_cols = i_cols + ny;
if it > maximum_lag+1
i_cols_A = i_cols_A + ny;
end
end
err = max(abs(res));
if options.debug
fprintf('\nLargest absolute residual at iteration %d: %10.3f\n',iter,err);
if any(isnan(res)) || any(isinf(res)) || any(isnan(Y)) || any(isinf(Y))
fprintf('\nWARNING: NaN or Inf detected in the residuals or endogenous variables.\n');
end
if ~isreal(res) || ~isreal(Y)
fprintf('\nWARNING: Imaginary parts detected in the residuals or endogenous variables.\n');
end
skipline()
end
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 = 1 ;
break
end
iA = iA(1:m,:);
A = sparse(iA(:,1),iA(:,2),iA(:,3),periods*ny,periods*ny);
if endogenous_terminal_period && iter>1
dy = ZERO;
if options.simul.robust_lin_solve
dy(1:i_rows(end)) = -lin_solve_robust( A(1:i_rows(end),1:i_rows(end)), res(1:i_rows(end)),verbose );
else
dy(1:i_rows(end)) = -lin_solve( A(1:i_rows(end),1:i_rows(end)), res(1:i_rows(end)), verbose );
end
else
if options.simul.robust_lin_solve
dy = -lin_solve_robust( A, res, verbose );
else
dy = -lin_solve( A, res, verbose );
end
end
if any(~isreal(dy)) || any(isnan(dy)) || any(isinf(dy))
if verbose
display_critical_variables(reshape(dy,[ny periods])', M);
end
end
Y(i_upd) = Y(i_upd) + dy;
end
if endogenous_terminal_period
err = evaluate_max_dynamic_residual(model_dynamic, Y, exogenousvariables, params, steadystate, o_periods, ny, max_lag, lead_lag_incidence);
periods = o_periods;
end
if stop
if any(isnan(res)) || any(isinf(res)) || any(isnan(Y)) || any(isinf(Y)) || ~isreal(res) || ~isreal(Y)
info.status = false;% NaN or Inf occurred
info.error = err;
info.iterations = iter;
info.periods = vperiods(1:iter);
endogenousvariables = reshape(Y,ny,periods+maximum_lag+M.maximum_lead);
if verbose
skipline()
disp(sprintf('Total time of simulation: %s.', num2str(etime(clock,h1))))
if ~isreal(res) || ~isreal(Y)
disp('Simulation terminated with imaginary parts in the residuals or endogenous variables.')
else
disp('Simulation terminated with NaN or Inf in the residuals or endogenous variables.')
end
display_critical_variables(reshape(dy,[ny periods])', M);
disp('There is most likely something wrong with your model. Try model_diagnostics or another simulation method.')
printline(105)
end
else
if verbose
skipline();
disp(sprintf('Total time of simulation: %s', num2str(etime(clock,h1))))
printline(56)
end
info.status = true;% Convergency obtained.
info.error = err;
info.iterations = iter;
info.periods = vperiods(1:iter);
endogenousvariables = reshape(Y,ny,periods+maximum_lag+M.maximum_lead);
end
elseif ~stop
if verbose
skipline();
disp(sprintf('Total time of simulation: %s.', num2str(etime(clock,h1))))
disp('Maximum number of iterations is reached (modify option maxit).')
printline(62)
end
info.status = false;% more iterations are needed.
info.error = err;
info.periods = vperiods(1:iter);
info.iterations = options.simul.maxit;
end
if verbose
skipline();
end
function x = lin_solve( A, b,verbose)
if norm( b ) < sqrt( eps ) % then x = 0 is a solution
x = 0;
return
end
x = A\b;
x( ~isfinite( x ) ) = 0;
relres = norm( b - A * x ) / norm( b );
if relres > 1e-6 && verbose
fprintf( 'WARNING : Failed to find a solution to the linear system.\n' );
end
function [ x, flag, relres ] = lin_solve_robust( A, b , verbose)
if norm( b ) < sqrt( eps ) % then x = 0 is a solution
x = 0;
flag = 0;
relres = 0;
return
end
x = A\b;
x( ~isfinite( x ) ) = 0;
[ x, flag, relres ] = bicgstab( A, b, [], [], [], [], x ); % returns immediately if x is a solution
if flag == 0
return
end
disp( relres );
if verbose
fprintf( 'Initial bicgstab failed, trying alternative start point.\n' );
end
old_x = x;
old_relres = relres;
[ x, flag, relres ] = bicgstab( A, b );
if flag == 0
return
end
if verbose
fprintf( 'Alternative start point also failed with bicgstab, trying gmres.\n' );
end
if old_relres < relres
x = old_x;
end
[ x, flag, relres ] = gmres( A, b, [], [], [], [], [], x );
if flag == 0
return
end
if verbose
fprintf( 'Initial gmres failed, trying alternative start point.\n' );
end
old_x = x;
old_relres = relres;
[ x, flag, relres ] = gmres( A, b );
if flag == 0
return
end
if verbose
fprintf( 'Alternative start point also failed with gmres, using the (SLOW) Moore-Penrose Pseudo-Inverse.\n' );
end
if old_relres < relres
x = old_x;
relres = old_relres;
end
old_x = x;
old_relres = relres;
x = pinv( full( A ) ) * b;
relres = norm( b - A * x ) / norm( b );
if old_relres < relres
x = old_x;
relres = old_relres;
end
flag = relres > 1e-6;
if flag ~= 0 && verbose
fprintf( 'WARNING : Failed to find a solution to the linear system\n' );
end
function display_critical_variables(dyy, M)
if any(isnan(dyy))
indx = find(any(isnan(dyy)));
endo_names= M.endo_names(indx);
disp('Last iteration provided NaN for the following variables:')
fprintf('%s, ', endo_names{:}),
fprintf('\n'),
end
if any(isinf(dyy))
indx = find(any(isinf(dyy)));
endo_names = M.endo_names(indx);
disp('Last iteration diverged (Inf) for the following variables:')
fprintf('%s, ', endo_names{:}),
fprintf('\n'),
end
if any(~isreal(dyy))
indx = find(any(~isreal(dyy)));
endo_names = M.endo_names(indx);
disp('Last iteration provided complex number for the following variables:')
fprintf('%s, ', endo_names{:}),
fprintf('\n'),
end