Completed the reversed extended path routines.

time-shift
Stéphane Adjemian (Scylla) 2010-05-12 16:52:26 +02:00
parent 135e802f73
commit 0889df6161
3 changed files with 60 additions and 23 deletions

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@ -1,4 +1,4 @@
function r = ep_residuals(x, y, ix, iy)
function r = ep_residuals(x, y, ix, iy, steadystate, dr, maximum_lag, endo_nbr)
% Inversion of the extended path simulation approach. This routine computes the innovations needed to
% reproduce the time path of a subset of endogenous variables.
%
@ -36,16 +36,32 @@ function r = ep_residuals(x, y, ix, iy)
global oo_
weight = 1.0;
tdx = M_.maximum_lag+1;
persistent k1 k2 weight
x = exp(transpose(x));
if isempty(k1)
k1 = [maximum_lag:-1:1];
k2 = dr.kstate(find(dr.kstate(:,2) <= maximum_lag+1),[1 2]);
k2 = k2(:,1)+(maximum_lag+1-k2(:,2))*endo_nbr;
weight = 0.99;
end
oo_.exo_simul(tdx,ix) = x;
exogenous_variables = zeros(size(oo_.exo_simul));
exogenous_variables(tdx,ix) = x;
initial_path = simult_(oo_.steady_state,dr,exogenous_variables,1);
oo_.endo_simul = weight*initial_path(:,1:end-1) + (1-weight)*oo_.endo_simul;
% Copy the shocks in exo_simul.
oo_.exo_simul(maximum_lag+1,ix) = exp(transpose(x));
exo_simul = log(oo_.exo_simul);
% Compute the initial solution path for the endogenous variables using a first order approximation.
initial_path = oo_.endo_simul;
for i = maximum_lag+1:size(oo_.exo_simul)
tempx1 = oo_.endo_simul(dr.order_var,k1);
tempx2 = bsxfun(@minus,tempx1,dr.ys(dr.order_var));
tempx = tempx2(k2);
initial_path(dr.order_var,i) = dr.ys(dr.order_var)+dr.ghx*tempx2(k2)+dr.ghu*transpose(exo_simul(i,:));
k1 = k1+1;
end
oo_.endo_simul = weight*initial_path + (1-weight)*oo_.endo_simul;
info = perfect_foresight_simulation(dr,steadystate);
r = y-transpose(oo_.endo_simul(maximum_lag+1,iy));
%(re)Set k1 (indices for the initial conditions)
k1 = [maximum_lag:-1:1];

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@ -1,13 +1,12 @@
function innovation_paths = reversed_extended_path(controlled_time_series, controlled_variable_names, control_innovation_names)
function innovation_paths = reversed_extended_path(controlled_variable_names, control_innovation_names, dataset)
% Inversion of the extended path simulation approach. This routine computes the innovations needed to
% reproduce the time path of a subset of endogenous variables. The initial condition is teh deterministic
% steady state.
%
% INPUTS
% o controlled_time_series [double] n*T matrix.
% INPUTS
% o controlled_variable_names [string] n*1 matlab's cell.
% o control_innovation_names [string] n*1 matlab's cell.
%
% o dataset [structure]
% OUTPUTS
% o innovations [double] n*T matrix.
%
@ -36,6 +35,14 @@ global M_ oo_ options_
%% Initialization
% Load data.
eval(dataset.name);
dataset.data = [];
for v = 1:dataset.number_of_observed_variables
eval(['dataset.data = [ dataset.data , ' dataset.variables(v,:) ' ];'])
end
data = dataset.data(dataset.first_observation:dataset.first_observation+dataset.number_of_observations,:);
% Compute the deterministic steady state.
steady_;
@ -44,27 +51,37 @@ old_options_order = options_.order; options_.order = 1;
[oo_.dr,info] = resol(oo_.steady_state,0);
options_.order = old_options_order;
% Set various options.
options_.periods = 100;
% Set-up oo_.exo_simul.
make_ex_;
% Set-up oo_.endo_simul.
make_y_;
% Get indices of the controlled endogenous variables
% Get indices of the controlled endogenous variables in endo_simul.
n = length(controlled_variable_names);
iy = NaN(n,1);
for k=1:n
iy(k) = strmatch(conrolled_variable_names{k},M_.endo_names,'exact');
iy(k) = strmatch(controlled_variable_names{k},M_.endo_names,'exact');
end
% Get indices of the control innovations.
% Get indices of the controlled endogenous variables in dataset.
iy_ = NaN(n,1);
for k=1:n
iy_(k) = strmatch(controlled_variable_names{k},dataset.variables,'exact');
end
% Get indices of the control innovations in exo_simul.
ix = NaN(n,1);
for k=1:n
ix(k) = strmatch(control_innovation_names{k},M_.exo_names,'exact');
end
% Get the length of the sample.
T = size(controlled_time_series,2);
T = size(data,1);
% Output initialization.
innovation_paths = zeros(n,T);
@ -72,11 +89,16 @@ innovation_paths = zeros(n,T);
% Initialization of the perfect foresight model solver.
perfect_foresight_simulation();
% Call fsolve recursively
%% Call fsolve recursively
for t=1:T
[tmp,fval,exitflag] = fsolve(ep_residuals,x0,[],y,ix,iy);
x0 = zeros(n,1);
y = transpose(data(t,iy_));
[tmp,fval,exitflag] = fsolve('ep_residuals', x0, [], y, ix, iy, oo_.steady_state, oo_.dr, M_.maximum_lag, M_.endo_nbr);
if exitflag==1
innovation_paths(:,t) = tmp;
end
% Update
% Update endo_simul.
oo_.endo_simul(:,1:end-1) = oo_.endo_simul(:,2:end);
oo_.endo_simul(:,end) = oo_.steady_state;
end

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@ -71,7 +71,6 @@ else
k3 = find(k3(:));
k4 = dr.kstate(find(dr.kstate(:,2) < M_.maximum_lag+1),[1 2]);
k4 = k4(:,1)+(M_.maximum_lag+1-k4(:,2))*M_.endo_nbr;
if iorder == 1
if ~isempty(dr.ghu)
for i = M_.maximum_lag+1: iter+M_.maximum_lag