dynare/nonlinear-filters/src/online_auxiliary_filter.m

373 lines
16 KiB
Matlab

function [xparam,std_param,lb_95,ub_95,median_param] = online_auxiliary_filter(xparam1,DynareDataset,DynareOptions,Model,EstimatedParameters,BayesInfo,DynareResults)
% Carvalho & Lopes particle filter = auxiliary particle filter including Liu & West filter on parameters.
%
% INPUTS
% ReducedForm [structure] Matlab's structure describing the reduced form model.
% ReducedForm.measurement.H [double] (pp x pp) variance matrix of measurement errors.
% ReducedForm.state.Q [double] (qq x qq) variance matrix of state errors.
% ReducedForm.state.dr [structure] output of resol.m.
% Y [double] pp*smpl matrix of (detrended) data, where pp is the maximum number of observed variables.
% start [integer] scalar, likelihood evaluation starts at 'start'.
% mf [integer] pp*1 vector of indices.
% number_of_particles [integer] scalar.
%
% OUTPUTS
% LIK [double] scalar, likelihood
% lik [double] vector, density of observations in each period.
%
% REFERENCES
%
% NOTES
% The vector "lik" is used to evaluate the jacobian of the likelihood.
% Copyright (C) 2013 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/>.
persistent Y init_flag mf0 mf1 bounds number_of_particles number_of_parameters liu_west_delta liu_west_chol_sigma_bar
persistent start_param sample_size number_of_observed_variables number_of_structural_innovations
% Set seed for randn().
set_dynare_seed('default') ;
pruning = DynareOptions.particle.pruning;
second_resample = 1 ;
variance_update = 1 ;
% initialization of state particles
[ys,trend_coeff,exit_flag,info,Model,DynareOptions,BayesInfo,DynareResults,ReducedForm] = ...
solve_model_for_online_filter(1,xparam1,DynareDataset,DynareOptions,Model,EstimatedParameters,BayesInfo,DynareResults) ;
% Set persistent variables.
if isempty(init_flag)
mf0 = ReducedForm.mf0;
mf1 = ReducedForm.mf1;
number_of_particles = DynareOptions.particle.number_of_particles;
number_of_parameters = size(xparam1,1) ;
Y = DynareDataset.data ;
sample_size = size(Y,2);
number_of_observed_variables = length(mf1);
number_of_structural_innovations = length(ReducedForm.Q);
liu_west_delta = DynareOptions.particle.liu_west_delta ;
%liu_west_chol_sigma_bar = DynareOptions.particle.liu_west_chol_sigma_bar*eye(number_of_parameters) ;
start_param = xparam1 ;
%liu_west_chol_sigma_bar = sqrt(bsxfun(@times,eye(number_of_parameters),BayesInfo.p2)) ;
%start_param = BayesInfo.p1 ;
bounds = [BayesInfo.lb BayesInfo.ub] ;
init_flag = 1;
end
% Get initial conditions for the state particles
StateVectorMean = ReducedForm.StateVectorMean;
StateVectorVarianceSquareRoot = reduced_rank_cholesky(ReducedForm.StateVectorVariance)';
state_variance_rank = size(StateVectorVarianceSquareRoot,2);
StateVectors = bsxfun(@plus,StateVectorVarianceSquareRoot*randn(state_variance_rank,number_of_particles),StateVectorMean);
if pruning
StateVectors_ = StateVectors;
end
% parameters for the Liu & West filter
h_square = (3*liu_west_delta-1)/(2*liu_west_delta) ;
h_square = 1-h_square*h_square ;
small_a = sqrt(1-h_square) ;
% Initialization of parameter particles
xparam = zeros(number_of_parameters,number_of_particles) ;
stderr = sqrt(bsxfun(@power,bounds(:,2)+bounds(:,1),2)/12)/100 ;
stderr = sqrt(bsxfun(@power,bounds(:,2)+bounds(:,1),2)/12)/50 ;
i = 1 ;
while i<=number_of_particles
%candidate = start_param + .001*liu_west_chol_sigma_bar*randn(number_of_parameters,1) ;
candidate = start_param + bsxfun(@times,stderr,randn(number_of_parameters,1)) ;
if all(candidate(:) >= bounds(:,1)) && all(candidate(:) <= bounds(:,2))
xparam(:,i) = candidate(:) ;
i = i+1 ;
end
end
%xparam = bsxfun(@plus,bounds(:,1),bsxfun(@times,(bounds(:,2)-bounds(:,1)),rand(number_of_parameters,number_of_particles))) ;
% Initialization of the weights of particles.
weights = ones(1,number_of_particles)/number_of_particles ;
% Initialization of the likelihood.
const_lik = log(2*pi)*number_of_observed_variables;
mean_xparam = zeros(number_of_parameters,sample_size) ;
median_xparam = zeros(number_of_parameters,sample_size) ;
std_xparam = zeros(number_of_parameters,sample_size) ;
lb95_xparam = zeros(number_of_parameters,sample_size) ;
ub95_xparam = zeros(number_of_parameters,sample_size) ;
%% The Online filter
for t=1:sample_size
disp(t)
% Moments of parameters particles distribution
m_bar = xparam*(weights') ;
temp = bsxfun(@minus,xparam,m_bar) ;
sigma_bar = (bsxfun(@times,weights,temp))*(temp') ;
if variance_update==1
chol_sigma_bar = chol(h_square*sigma_bar)' ;
end
% Prediction (without shocks)
ObservedVariables = zeros(number_of_observed_variables,number_of_particles) ;
for i=1:number_of_particles
% model resolution
[ys,trend_coeff,exit_flag,info,Model,DynareOptions,BayesInfo,DynareResults,ReducedForm] = ...
solve_model_for_online_filter(t,xparam(:,i),DynareDataset,DynareOptions,Model,EstimatedParameters,BayesInfo,DynareResults) ;
steadystate = ReducedForm.steadystate;
state_variables_steady_state = ReducedForm.state_variables_steady_state;
% Set local state space model (second-order approximation).
constant = ReducedForm.constant;
ghx = ReducedForm.ghx;
ghu = ReducedForm.ghu;
ghxx = ReducedForm.ghxx;
ghuu = ReducedForm.ghuu;
ghxu = ReducedForm.ghxu;
% particle likelihood contribution
yhat = bsxfun(@minus,StateVectors(:,i),state_variables_steady_state);
if pruning
yhat_ = bsxfun(@minus,StateVectors_(:,i),state_variables_steady_state);
[tmp, tmp_] = local_state_space_iteration_2(yhat,zeros(number_of_structural_innovations,1),ghx,ghu,constant,ghxx,ghuu,ghxu,yhat_,steadystate,DynareOptions.threads.local_state_space_iteration_2);
else
tmp = local_state_space_iteration_2(yhat,zeros(number_of_structural_innovations,1),ghx,ghu,constant,ghxx,ghuu,ghxu,DynareOptions.threads.local_state_space_iteration_2);
end
ObservedVariables(:,i) = tmp(mf1,:) ;
end
PredictedObservedMean = sum(bsxfun(@times,weights,ObservedVariables),2) ;
PredictionError = bsxfun(@minus,Y(:,t),ObservedVariables);
dPredictedObservedMean = bsxfun(@minus,ObservedVariables,PredictedObservedMean);
PredictedObservedVariance = bsxfun(@times,weights,dPredictedObservedMean)*dPredictedObservedMean' + ReducedForm.H ;
wtilde = exp(-.5*(const_lik+log(det(PredictedObservedVariance))+sum(PredictionError.*(PredictedObservedVariance\PredictionError),1))) ;
% unormalized weights and observation likelihood contribution
tau_tilde = weights.*wtilde ;
sum_tau_tilde = sum(tau_tilde) ;
% particles selection
tau_tilde = tau_tilde/sum_tau_tilde ;
indx = index_resample(0,tau_tilde',DynareOptions);
StateVectors = StateVectors(:,indx) ;
if pruning
StateVectors_ = StateVectors_(:,indx) ;
end
xparam = bsxfun(@plus,(1-small_a).*m_bar,small_a.*xparam) ;
xparam = xparam(:,indx) ;
wtilde = wtilde(indx) ;
% draw in the new distributions
i = 1 ;
while i<=number_of_particles
candidate = xparam(:,i) + chol_sigma_bar*randn(number_of_parameters,1) ;
if all(candidate >= bounds(:,1)) && all(candidate <= bounds(:,2))
xparam(:,i) = candidate ;
% model resolution for new parameters particles
[ys,trend_coeff,exit_flag,info,Model,DynareOptions,BayesInfo,DynareResults,ReducedForm] = ...
solve_model_for_online_filter(t,xparam(:,i),DynareDataset,DynareOptions,Model,EstimatedParameters,BayesInfo,DynareResults) ;
steadystate = ReducedForm.steadystate;
state_variables_steady_state = ReducedForm.state_variables_steady_state;
% Set local state space model (second order approximation).
constant = ReducedForm.constant;
ghx = ReducedForm.ghx;
ghu = ReducedForm.ghu;
ghxx = ReducedForm.ghxx;
ghuu = ReducedForm.ghuu;
ghxu = ReducedForm.ghxu;
% Get covariance matrices and structural shocks
epsilon = chol(ReducedForm.Q)'*randn(number_of_structural_innovations,1) ;
% compute particles likelihood contribution
yhat = bsxfun(@minus,StateVectors(:,i),state_variables_steady_state);
if pruning
yhat_ = bsxfun(@minus,StateVectors_(:,i),state_variables_steady_state);
[tmp, tmp_] = local_state_space_iteration_2(yhat,epsilon,ghx,ghu,constant,ghxx,ghuu,ghxu,yhat_,steadystate,DynareOptions.threads.local_state_space_iteration_2);
StateVectors_(:,i) = tmp_(mf0,:) ;
else
tmp = local_state_space_iteration_2(yhat,epsilon,ghx,ghu,constant,ghxx,ghuu,ghxu,DynareOptions.threads.local_state_space_iteration_2);
end
StateVectors(:,i) = tmp(mf0,:) ;
ObservedVariables(:,i) = tmp(mf1,:) ;
i = i+1 ;
end
end
PredictedObservedMean = sum(bsxfun(@times,weights,ObservedVariables),2) ;
PredictionError = bsxfun(@minus,Y(:,t),ObservedVariables);
dPredictedObservedMean = bsxfun(@minus,ObservedVariables,PredictedObservedMean);
PredictedObservedVariance = bsxfun(@times,weights,dPredictedObservedMean)*dPredictedObservedMean' + ReducedForm.H ;
lnw = exp(-.5*(const_lik+log(det(PredictedObservedVariance))+sum(PredictionError.*(PredictedObservedVariance\PredictionError),1)));
% importance ratio
wtilde = lnw./wtilde ;
% normalization
weights = wtilde/sum(wtilde);
if (variance_update==1) && (neff(weights)<DynareOptions.particle.resampling.threshold*sample_size)
variance_update = 0 ;
end
% final resampling (advised)
if second_resample==1
indx = index_resample(0,weights,DynareOptions);
StateVectors = StateVectors(:,indx) ;
if pruning
StateVectors_ = StateVectors_(:,indx) ;
end
xparam = xparam(:,indx) ;
weights = ones(1,number_of_particles)/number_of_particles ;
mean_xparam(:,t) = mean(xparam,2);
mat_var_cov = bsxfun(@minus,xparam,mean_xparam(:,t)) ;
mat_var_cov = (mat_var_cov*mat_var_cov')/(number_of_particles-1) ;
std_xparam(:,t) = sqrt(diag(mat_var_cov)) ;
for i=1:number_of_parameters
temp = sortrows(xparam(i,:)') ;
lb95_xparam(i,t) = temp(0.025*number_of_particles) ;
median_xparam(i,t) = temp(0.5*number_of_particles) ;
ub95_xparam(i,t) = temp(0.975*number_of_particles) ;
end
end
if second_resample==0
mean_xparam(:,t) = xparam*(weights') ;
mat_var_cov = bsxfun(@minus,xparam,mean_xparam(:,t)) ;
mat_var_cov = mat_var_cov*(bsxfun(@times,mat_var_cov,weights)') ;
std_xparam(:,t) = sqrt(diag(mat_var_cov)) ;
for i=1:number_of_parameters
temp = sortrows([xparam(i,:)' weights'],1) ;
cumulated_weights = cumsum(temp(:,2)) ;
pass1=1 ;
pass2=1 ;
pass3=1 ;
for j=1:number_of_particles
if cumulated_weights(j)>0.025 && pass1==1
lb95_xparam(i,t) = (temp(j-1,1)+temp(j,1))/2 ;
pass1 = 2 ;
end
if cumulated_weights(j)>0.5 && pass2==1
median_xparam(i,t) = (temp(j-1,1)+temp(j,1))/2 ;
pass2 = 2 ;
end
if cumulated_weights(j)>0.975 && pass3==1
ub95_xparam(i,t) = (temp(j-1,1)+temp(j,1))/2 ;
pass3 = 2 ;
end
end
end
end
disp([lb95_xparam(:,t) mean_xparam(:,t) ub95_xparam(:,t)])
end
distrib_param = xparam ;
xparam = mean_xparam(:,sample_size) ;
std_param = std_xparam(:,sample_size) ;
lb_95 = lb95_xparam(:,sample_size) ;
ub_95 = ub95_xparam(:,sample_size) ;
median_param = median_xparam(:,sample_size) ;
%% Plot parameters trajectory
TeX = DynareOptions.TeX;
[nbplt,nr,nc,lr,lc,nstar] = pltorg(number_of_parameters);
if TeX
fidTeX = fopen([Model.fname '_param_traj.TeX'],'w');
fprintf(fidTeX,'%% TeX eps-loader file generated by online_auxiliary_filter.m (Dynare).\n');
fprintf(fidTeX,['%% ' datestr(now,0) '\n']);
fprintf(fidTeX,' \n');
end
z = 1:1:sample_size ;
for plt = 1:nbplt,
if TeX
NAMES = [];
TeXNAMES = [];
end
hh = dyn_figure(DynareOptions,'Name','Parameters Trajectories');
for k=1:min(nstar,length(xparam)-(plt-1)*nstar)
subplot(nr,nc,k)
kk = (plt-1)*nstar+k;
[name,texname] = get_the_name(kk,TeX,Model,EstimatedParameters,DynareOptions);
if TeX
if isempty(NAMES)
NAMES = name;
TeXNAMES = texname;
else
NAMES = char(NAMES,name);
TeXNAMES = char(TeXNAMES,texname);
end
end
y = [mean_xparam(kk,:)' median_xparam(kk,:)' lb95_xparam(kk,:)' ub95_xparam(kk,:)' xparam(kk)*ones(sample_size,1)] ;
plot(z,y);
hold on
title(name,'interpreter','none')
hold off
axis tight
drawnow
end
dyn_saveas(hh,[ Model.fname '_param_traj' int2str(plt) ],DynareOptions);
if TeX
% TeX eps loader file
fprintf(fidTeX,'\\begin{figure}[H]\n');
for jj = 1:min(nstar,length(x)-(plt-1)*nstar)
fprintf(fidTeX,'\\psfrag{%s}[1][][0.5][0]{%s}\n',deblank(NAMES(jj,:)),deblank(TeXNAMES(jj,:)));
end
fprintf(fidTeX,'\\centering \n');
fprintf(fidTeX,'\\includegraphics[scale=0.5]{%s_ParamTraj%s}\n',Model.fname,int2str(plt));
fprintf(fidTeX,'\\caption{Parameters trajectories.}');
fprintf(fidTeX,'\\label{Fig:ParametersPlots:%s}\n',int2str(plt));
fprintf(fidTeX,'\\end{figure}\n');
fprintf(fidTeX,' \n');
end
end
%% Plot Parameter Densities
number_of_grid_points = 2^9; % 2^9 = 512 !... Must be a power of two.
bandwidth = 0; % Rule of thumb optimal bandwidth parameter.
kernel_function = 'gaussian'; % Gaussian kernel for Fast Fourier Transform approximation.
for plt = 1:nbplt,
if TeX
NAMES = [];
TeXNAMES = [];
end
hh = dyn_figure(DynareOptions,'Name','Parameters Densities');
for k=1:min(nstar,length(xparam)-(plt-1)*nstar)
subplot(nr,nc,k)
kk = (plt-1)*nstar+k;
[name,texname] = get_the_name(kk,TeX,Model,EstimatedParameters,DynareOptions);
if TeX
if isempty(NAMES)
NAMES = name;
TeXNAMES = texname;
else
NAMES = char(NAMES,name);
TeXNAMES = char(TeXNAMES,texname);
end
end
optimal_bandwidth = mh_optimal_bandwidth(distrib_param(kk,:)',number_of_particles,bandwidth,kernel_function);
[density(:,1),density(:,2)] = kernel_density_estimate(distrib_param(kk,:)',number_of_grid_points,...
number_of_particles,optimal_bandwidth,kernel_function);
plot(density(:,1),density(:,2));
hold on
title(name,'interpreter','none')
hold off
axis tight
drawnow
end
dyn_saveas(hh,[ Model.fname '_param_density' int2str(plt) ],DynareOptions);
if TeX
% TeX eps loader file
fprintf(fidTeX,'\\begin{figure}[H]\n');
for jj = 1:min(nstar,length(x)-(plt-1)*nstar)
fprintf(fidTeX,'\\psfrag{%s}[1][][0.5][0]{%s}\n',deblank(NAMES(jj,:)),deblank(TeXNAMES(jj,:)));
end
fprintf(fidTeX,'\\centering \n');
fprintf(fidTeX,'\\includegraphics[scale=0.5]{%s_ParametersDensities%s}\n',Model.fname,int2str(plt));
fprintf(fidTeX,'\\caption{ParametersDensities.}');
fprintf(fidTeX,'\\label{Fig:ParametersDensities:%s}\n',int2str(plt));
fprintf(fidTeX,'\\end{figure}\n');
fprintf(fidTeX,' \n');
end
end