Fix UnivariateSpectralDensity.m for filtered variables

- Adds bandpass filter
- Writes results to oo_
time-shift
Johannes Pfeifer 2015-08-04 08:45:55 +02:00
parent 25df325899
commit a4b04ca9b4
2 changed files with 63 additions and 76 deletions

View File

@ -1,11 +1,25 @@
function [omega,f] = UnivariateSpectralDensity(dr,var_list)
function [oo_] = UnivariateSpectralDensity(M_,oo_,options_,var_list)
% This function computes the theoretical spectral density of each
% endogenous variable declared in var_list. Results are stored in
% oo_ and may be plotted. Plots are saved into the graphs-folder.
% oo_.SpectralDensity and may be plotted. Plots are saved into the
% graphs-folder.
%
% INPUTS
% M_ [structure] Dynare's model structure
% oo_ [structure] Dynare's results structure
% options_ [structure] Dynare's options structure
% var_list [integer] Vector of indices for a subset of variables.
%
% OUTPUTS
% oo_ [structure] Dynare's results structure,
% containing the subfield
% SpectralDensity with fields freqs
% and density, which are of size nvar*ngrid.
%
% Adapted from th_autocovariances.m.
% Copyright (C) 2006-2013 Dynare Team
% Copyright (C) 2006-2015 Dynare Team
%
% This file is part of Dynare.
%
@ -22,10 +36,6 @@ function [omega,f] = UnivariateSpectralDensity(dr,var_list)
% You should have received a copy of the GNU General Public License
% along with Dynare. If not, see <http://www.gnu.org/licenses/>.
global options_ oo_ M_
omega = []; f = [];
if options_.order > 1
disp('UnivariateSpectralDensity :: I Cannot compute the theoretical spectral density')
@ -33,12 +43,7 @@ if options_.order > 1
disp('Please set order = 1. I abort')
return
end
pltinfo = options_.SpectralDensity.plot;
cutoff = options_.SpectralDensity.cutoff;
sdl = options_.SpectralDensity.sdl;
omega = (0:sdl:pi)';
GridSize = length(omega);
exo_names_orig_ord = M_.exo_names_orig_ord;
if isoctave
warning('off', 'Octave:divide-by-zero')
else
@ -60,22 +65,19 @@ for i=1:nvar
ivar(i) = i_tmp;
end
end
f = zeros(nvar,GridSize);
ghx = dr.ghx;
ghu = dr.ghu;
ghx = oo_.dr.ghx;
ghu = oo_.dr.ghu;
nspred = M_.nspred;
nstatic = M_.nstatic;
kstate = dr.kstate;
order = dr.order_var;
kstate = oo_.dr.kstate;
order = oo_.dr.order_var;
iv(order) = [1:length(order)];
nx = size(ghx,2);
ikx = [nstatic+1:nstatic+nspred];
A = zeros(nx,nx);
k0 = kstate(find(kstate(:,2) <= M_.maximum_lag+1),:);
i0 = find(k0(:,2) == M_.maximum_lag+1);
i00 = i0;
n0 = length(i0);
A(i0,:) = ghx(ikx,:);
AS = ghx(:,i0);
ghu1 = zeros(nx,M_.exo_nbr);
ghu1(i0,:) = ghu(ikx,:);
@ -91,87 +93,72 @@ for i=M_.maximum_lag:-1:2
AS(:,j1) = AS(:,j1)+ghx(:,i1);
i0 = i1;
end
Gamma = zeros(nvar,cutoff+1);
[A,B] = kalman_transition_matrix(dr,ikx',1:nx,M_.exo_nbr);
[A,B] = kalman_transition_matrix(oo_.dr,ikx',1:nx,M_.exo_nbr);
[vx, u] = lyapunov_symm(A,B*M_.Sigma_e*B',options_.lyapunov_fixed_point_tol,options_.qz_criterium,options_.lyapunov_complex_threshold,[],[],options_.debug);
iky = iv(ivar);
if ~isempty(u)
iky = iky(find(any(abs(ghx(iky,:)*u) < options_.Schur_vec_tol,2)));
ivar = dr.order_var(iky);
ivar = oo_.dr.order_var(iky);
end
iky = iv(ivar);
aa = ghx(iky,:);
bb = ghu(iky,:);
if options_.hp_filter == 0
tmp = aa*vx*aa'+ bb*M_.Sigma_e*bb';
tmp(abs(tmp) < 1e-12) = 0;
Gamma(:,1) = diag(tmp);
vxy = (A*vx*aa'+ghu1*M_.Sigma_e*bb');
tmp = aa*vxy;
tmp(abs(tmp) < 1e-12) = 0;
Gamma(:,2) = diag(tmp);
for i=2:cutoff
vxy = A*vxy;
tmp = aa*vxy;
tmp(abs(tmp) < 1e-12) = 0;
Gamma(:,i+1) = diag(tmp);
end
else
iky = iv(ivar);
aa = ghx(iky,:);
bb = ghu(iky,:);
ngrid = options_.hp_ngrid; %number of grid points
freqs = (0 : pi/(ngrid-1):pi)'; % grid on which to compute
tpos = exp( sqrt(-1)*freqs); %positive frequencies
tneg = exp(-sqrt(-1)*freqs); %negative frequencies
if options_.hp_filter == 0 && ~options_.bandpass.indicator %do not filter
filter_gain=ones(ngrid,1);
elseif ~(options_.hp_filter == 0 && ~options_.bandpass.indicator) && options_.bandpass.indicator %filter with bandpass
filter_gain = zeros(1,ngrid);
lowest_periodicity=options_.bandpass.passband(2);
highest_periodicity=options_.bandpass.passband(1);
highest_periodicity=max(2,highest_periodicity); % restrict to upper bound of pi
filter_gain(freqs>=2*pi/lowest_periodicity & freqs<=2*pi/highest_periodicity)=1;
filter_gain(freqs<=-2*pi/lowest_periodicity+2*pi & freqs>=-2*pi/highest_periodicity+2*pi)=1;
elseif ~(options_.hp_filter == 0 && ~options_.bandpass.indicator) && ~options_.bandpass.indicator %filter with HP-filter
lambda = options_.hp_filter;
ngrid = options_.hp_ngrid;
freqs = 0 : ((2*pi)/ngrid) : (2*pi*(1 - .5/ngrid));
tpos = exp( sqrt(-1)*freqs);
tneg = exp(-sqrt(-1)*freqs);
hp1 = 4*lambda*(1 - cos(freqs)).^2 ./ (1 + 4*lambda*(1 - cos(freqs)).^2);
mathp_col = NaN(ngrid,length(ivar)^2);
IA = eye(size(A,1));
IE = eye(M_.exo_nbr);
for ig = 1:ngrid
f_omega =(1/(2*pi))*( [(IA-A*tneg(ig))\ghu1;IE]...
*M_.Sigma_e*[ghu1'/(IA-A'*tpos(ig)) IE]); % state variables
g_omega = [aa*tneg(ig) bb]*f_omega*[aa'*tpos(ig); bb']; % selected variables
f_hp = hp1(ig)^2*g_omega; % spectral density of selected filtered series
mathp_col(ig,:) = (f_hp(:))'; % store as matrix row
% for ifft
end;
imathp_col = real(ifft(mathp_col))*(2*pi);
tmp = reshape(imathp_col(1,:),nvar,nvar);
tmp(abs(tmp)<1e-12) = 0;
Gamma(:,1) = diag(tmp);
sy = sqrt(Gamma(:,1));
sy = sy *sy';
for i=1:cutoff-1
tmp = reshape(imathp_col(i+1,:),nvar,nvar)./sy;
tmp(abs(tmp) < 1e-12) = 0;
Gamma(:,i+1) = diag(tmp);
end
filter_gain = 4*lambda*(1 - cos(freqs)).^2 ./ (1 + 4*lambda*(1 - cos(freqs)).^2);
end
H = 1:cutoff;
mathp_col = NaN(ngrid,length(ivar)^2);
IA = eye(size(A,1));
IE = eye(M_.exo_nbr);
for ig = 1:ngrid
f_omega =(1/(2*pi))*( [(IA-A*tneg(ig))\ghu1;IE]...
*M_.Sigma_e*[ghu1'/(IA-A'*tpos(ig)) IE]); % state variables
g_omega = [aa*tneg(ig) bb]*f_omega*[aa'*tpos(ig); bb']; % selected variables
f_hp = filter_gain(ig)^2*g_omega; % spectral density of selected filtered series
mathp_col(ig,:) = (f_hp(:))'; % store as matrix row
end;
f = zeros(nvar,ngrid);
for i=1:nvar
f(i,:) = Gamma(i,1)/(2*pi) + Gamma(i,H+1)*cos(H'*omega')/pi;
f(i,:) = real(mathp_col(:,(i-1)*nvar+i)); %read out spectral density
end
oo_.SpectralDensity.freqs=freqs;
oo_.SpectralDensity.density=f;
if isoctave
warning('on', 'Octave:divide-by-zero')
else
warning on MATLAB:dividebyzero
end
if pltinfo
if options_.nograph == 0
if ~exist(M_.fname, 'dir')
mkdir('.',M_.fname);
end
if ~exist([M_.fname '/graphs'])
if ~exist([M_.fname '/graphs'],'dir')
mkdir(M_.fname,'graphs');
end
for i= 1:nvar
hh = dyn_figure(options_,'Name',['Spectral Density of ' deblank(M_.endo_names(ivar(i),:)) '.']);
plot(omega,f(i,:),'-k','linewidth',2)
plot(freqs,f(i,:),'-k','linewidth',2)
xlabel('0 \leq \omega \leq \pi')
ylabel('f(\omega)')
box on

View File

@ -350,7 +350,7 @@ if options_.irf
end
if options_.SpectralDensity.trigger == 1
[omega,f] = UnivariateSpectralDensity(oo_.dr,var_list);
[oo_] = UnivariateSpectralDensity(M_,oo_,options_,var_list);
end