dynare/matlab/shock_decomposition.m

73 lines
2.0 KiB
Matlab
Raw Normal View History

function z = shock_decomposition(M_,oo_,varlist)
% function z = shock_decomposition(R,epsilon,varlist)
% Computes shocks contribution to a simulated trajectory
%
% INPUTS
% R: mm*rr matrix of shock impact
% epsilon: rr*nobs matrix of shocks
% varlist: list of variables
%
% OUTPUTS
% z: nvar*rr*nobs shock decomposition
%
% SPECIAL REQUIREMENTS
% none
%
% part of DYNARE, copyright Dynare Team (2004-2008)
% Gnu Public License.
% number of variables
endo_nbr = M_.endo_nbr;
% number of shocks
nshocks = M_.exo_nbr;
% indices of endogenous variables
[i_var,nvar] = varlist_indices(varlist);
% reduced form
dr = oo_.dr;
% data reordering
order_var = dr.order_var;
inv_order_var = dr.inv_order_var;
% coefficients
A = dr.ghx;
B = dr.ghu;
% initialization
for i=1:nshocks
epsilon(i,:) = eval(['oo_.SmoothedShocks.' M_.exo_names(i,:)]);
end
gend = size(epsilon,2);
z = zeros(endo_nbr,nshocks+2,gend);
for i=1:endo_nbr
z(i,end,:) = eval(['oo_.SmoothedVariables.' M_.endo_names(i,:)]);
end
maximum_lag = M_.maximum_lag;
lead_lag_incidence = M_.lead_lag_incidence;
for i=1:gend
if i > 1 & i <= maximum_lag+1
lags = min(i-1,maximum_lag):-1:1;
k2 = dr.kstate(find(dr.kstate(:,2) <= min(i,maximum_lag)+1),[1 2]);
i_state = order_var(k2(:,1))+(min(i,maximum_lag)+1-k2(:,2))*M_.endo_nbr;
end
if i > 1
tempx = permute(z(:,1:nshocks,lags),[1 3 2]);
m = min(i-1,maximum_lag);
tempx = [reshape(tempx,endo_nbr*m,nshocks); zeros(endo_nbr*(maximum_lag-i+1),nshocks)];
z(:,1:nshocks,i) = A(inv_order_var,:)*tempx(i_state,:);
lags = lags+1;
end
z(:,1:nshocks,i) = z(:,1:nshocks,i) + B(inv_order_var,:).*repmat(epsilon(:,i)',nvar,1);
z(:,nshocks+1,i) = z(:,nshocks+2,i) - sum(z(:,1:nshocks,i),2);
end