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function [z2,eu2,div]=gensys_z2new(g0,g1,c,psi,gpi)
%[z2,eu2,div]=gensys_z2new(g0,g1,c,psi,gpi)
%
% z2: n-by-k in general where k is the dimension of gpi or the number of expectational errors.
% System given as
% g0*y(t)=g1*y(t-1)+c+psi*z(t)+gpi*eta(t),
% with z an exogenous variable process and eta being endogenously determined
% one-step-ahead expectational errors.
% Space spanned by z2 is such that z2'*y_t = 0.
% If div is omitted from argument list, a div>1 is calculated.
%
% eu2 = [0, 0] if the rows in Z2 corresponding to the fixed points are zeros (which happens only in the greater-than-2 regime case).
% This value is set outside this function.
% eu2 = [-2,-2] for coincident zeros.
% By Christopher A. Sims
% Corrected 10/28/96 by CAS
%
% Copyright (C) 1997-2012 Christopher A. Sims
%
% This 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.
%
% It 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.
%
% If you did not received a copy of the GNU General Public License
% with this software, see <http://www.gnu.org/licenses/>.
%
eu2=NaN*ones(2,1);
n2 = size(gpi,2); %number of expectational errors.
realsmall=1e-9;
%fixdiv=(nargin==6);
n=size(g0,1);
[a b q z v]=qz(g0,g1);
%if ~fixdiv, div=1.01; end
%nunstab=0;
zxz=0;
for i=1:n
% ------------------div calc------------
% if ~fixdiv
% if abs(a(i,i)) > 0
% divhat=abs(b(i,i))/abs(a(i,i));
% % bug detected by Vasco Curdia and Daria Finocchiaro, 2/25/2004 A root of
% % exactly 1.01 and no root between 1 and 1.02, led to div being stuck at 1.01
% % and the 1.01 root being misclassified as stable. Changing < to <= below fixes this.
% if 1+realsmall<divhat & divhat<=div
% div=.5*(1+divhat);
% end
% end
% end
% ----------------------------------------
%nunstab=nunstab+(abs(b(i,i))>div*abs(a(i,i)));
if abs(a(i,i))<realsmall & abs(b(i,i))<realsmall
zxz=1;
end
end
gev=[diag(a) diag(b)];
gevsort = sort(abs(gev(:,1)).\abs(gev(:,2)));
div = (gevsort(end-n2+1) + gevsort(end-n2))/2.0;
if ~zxz
[a b q z]=qzdiv(div,a,b,q,z);
end
if zxz
disp('Coincident zeros. Indeterminacy and/or nonexistence.')
eu2=[-2;-2];
% correction added 7/29/2003. Otherwise the failure to set output
% arguments leads to an error message and no output (including eu2).
G1=[];C=[];impact=[];fmat=[];fwt=[];ywt=[];gev=[];
z2=[];
return
end
%q1=q(1:n-nunstab,:);
%q2=q(n-nunstab+1:n,:);
%z1=z(:,1:n-nunstab)';
%if (nunstab>0)
% z2=z(:,n-nunstab+1:n);
%else
% z2=z(:,n-n2+1:n);
%end
z2=z(:,n-n2+1:n);
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