1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136
|
function [marginal,oo_] = marginal_density(M_, options_, estim_params_, oo_, bayestopt_, outputFolderName)
% function [marginal,oo_] = marginal_density(M_, options_, estim_params_, oo_, bayestopt_, outputFolderName)
% Computes the marginal density
%
% INPUTS
% options_ [structure] Dynare options structure
% estim_params_ [structure] Dynare estimation parameter structure
% M_ [structure] Dynare model structure
% oo_ [structure] Dynare results structure
% outputFolderName [string] name of folder with results
%
% OUTPUTS
% marginal: [double] marginal density (modified harmonic mean)
% oo_ [structure] Dynare results structure
%
% SPECIAL REQUIREMENTS
% none
% Copyright © 2005-2023 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/>.
if nargin < 6
outputFolderName = 'Output';
end
MetropolisFolder = CheckPath('metropolis',M_.dname);
ModelName = M_.fname;
BaseName = [MetropolisFolder filesep ModelName];
record=load_last_mh_history_file(MetropolisFolder, ModelName);
[nblck, npar] = size(record.LastParameters);
FirstMhFile = record.KeepedDraws.FirstMhFile;
FirstLine = record.KeepedDraws.FirstLine;
TotalNumberOfMhFiles = sum(record.MhDraws(:,2));
TotalNumberOfMhDraws = sum(record.MhDraws(:,1));
TODROP = floor(options_.mh_drop*TotalNumberOfMhDraws);
fprintf('marginal density: I''m computing the posterior mean and covariance... ');
[posterior_mean, posterior_covariance, posterior_mode, posterior_kernel_at_the_mode] = compute_posterior_covariance_matrix(bayestopt_.name, M_.fname, M_.dname, options_, outputFolderName);
MU = transpose(posterior_mean);
SIGMA = posterior_covariance;
lpost_mode = posterior_kernel_at_the_mode;
xparam1 = posterior_mean;
hh = inv(SIGMA);
fprintf(' Done!\n');
if ~isfield(oo_,'posterior_mode') || (options_.mh_replic && isequal(options_.posterior_sampler_options.posterior_sampling_method,'slice'))
oo_=fill_mh_mode(posterior_mode',NaN(npar,1),M_,options_,estim_params_,oo_,'posterior');
end
% save the posterior mean and the inverse of the covariance matrix
% (usefull if the user wants to perform some computations using
% the posterior mean instead of the posterior mode ==> ).
parameter_names = bayestopt_.name;
save([M_.dname filesep outputFolderName filesep M_.fname '_mean.mat'],'xparam1','hh','parameter_names','SIGMA');
fprintf('marginal density: I''m computing the posterior log marginal density (modified harmonic mean)... ');
try
% use this robust option to avoid inf/nan
logdetSIGMA = 2*sum(log(diag(chol(SIGMA))));
catch
% in case SIGMA is not positive definite
logdetSIGMA = nan;
fprintf('marginal density: the covariance of MCMC draws is not positive definite. You may have too few MCMC draws.');
end
invSIGMA = hh;
marginal = zeros(9,2);
linee = 0;
check_coverage = 1;
increase = 1;
while check_coverage
for p = 0.1:0.1:0.9
critval = chi2inv(p,npar);
ifil = FirstLine;
tmp = 0;
for n = FirstMhFile:TotalNumberOfMhFiles
for b=1:nblck
load([ BaseName '_mh' int2str(n) '_blck' int2str(b) '.mat'],'x2','logpo2');
EndOfFile = size(x2,1);
for i = ifil:EndOfFile
deviation = ((x2(i,:)-MU)*invSIGMA*(x2(i,:)-MU)')/increase;
if deviation <= critval
lftheta = -log(p)-(npar*log(2*pi)+(npar*log(increase)+logdetSIGMA)+deviation)/2;
tmp = tmp + exp(lftheta - logpo2(i) + lpost_mode);
end
end
end
ifil = 1;
end
linee = linee + 1;
warning_old_state = warning;
warning off;
marginal(linee,:) = [p, lpost_mode-log(tmp/((TotalNumberOfMhDraws-TODROP)*nblck))];
warning(warning_old_state);
end
if abs((marginal(9,2)-marginal(1,2))/marginal(9,2)) > options_.marginal_data_density.harmonic_mean.tolerance || isinf(marginal(1,2))
fprintf('\n')
if increase == 1
disp('marginal density: The support of the weighting density function is not large enough...')
disp('marginal density: I increase the variance of this distribution.')
increase = 1.2*increase;
linee = 0;
else
disp('marginal density: Let me try again.')
increase = 1.2*increase;
linee = 0;
if increase > 20
check_coverage = 0;
clear invSIGMA detSIGMA increase;
disp('marginal density: There''s probably a problem with the modified harmonic mean estimator.')
end
end
else
check_coverage = 0;
clear invSIGMA detSIGMA increase;
fprintf('Done!\n')
end
end
oo_.MarginalDensity.ModifiedHarmonicMean = mean(marginal(:,2));
|