50 lines
1.3 KiB
Matlab
50 lines
1.3 KiB
Matlab
function g = weibull_rejection(a, b)
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% Returns gamma variates, see Devroye (1986) page 415.
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%
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% INPUTS
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% - a [double] n*1 vector, first hyperparameter.
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% - b [double] n*1 vector, second hyperparameter.
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%
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% OUTPUTS
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% - g [double] n*1 vector, gamma variates.
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% Copyright (C) 2006-2018 Dynare Team
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%
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% This file is part of Dynare.
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%
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% Dynare is free software: you can redistribute it and/or modify
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% it under the terms of the GNU General Public License as published by
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% the Free Software Foundation, either version 3 of the License, or
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% (at your option) any later version.
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%
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% Dynare is distributed in the hope that it will be useful,
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% but WITHOUT ANY WARRANTY; without even the implied warranty of
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% MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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% GNU General Public License for more details.
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%
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% You should have received a copy of the GNU General Public License
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% along with Dynare. If not, see <http://www.gnu.org/licenses/>.
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nn = length(a);
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mm = nn;
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cc = 1./a ;
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dd = a.^(a./(1-a)).*(1-a);
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ZE = NaN(nn,2);
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X = NaN(nn,1);
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INDEX = 1:mm;
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index = INDEX;
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while mm
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ZE(index,:) = exprnd(ones(mm,2));
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X(index) = ZE(index,1).^cc(index);
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id = find( (ZE(:,1)+ZE(:,2) > dd + X) );
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if isempty(id)
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mm = 0;
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else
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index = INDEX(id);
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mm = length(index);
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end
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end
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g = X.*b; |