From 111347469fe0a155f47e8fd09497f4ba20351697 Mon Sep 17 00:00:00 2001
From: Michel Juillard <michel.juillard@mjui.fr>
Date: Mon, 9 Jan 2012 21:23:17 +0100
Subject: [PATCH] adding comment explaining initialization of persistent
 variable penalty in dsge_likelihood.m and dsge_likelihood_hh.m Removed
 misleading initialization code. Added call to dsge_likelihood_hh in
 initial_estimation_checks to initialize persistent variable in that function
 as well.

---
 matlab/dsge_likelihood.m           | 24 ++++++++++++++----------
 matlab/dsge_likelihood_hh.m        | 23 +++++++++++++----------
 matlab/initial_estimation_checks.m |  6 ++++++
 3 files changed, 33 insertions(+), 20 deletions(-)

diff --git a/matlab/dsge_likelihood.m b/matlab/dsge_likelihood.m
index 08393a1a9..5a3eead06 100644
--- a/matlab/dsge_likelihood.m
+++ b/matlab/dsge_likelihood.m
@@ -127,17 +127,21 @@ function [fval,exit_flag,ys,trend_coeff,info,Model,DynareOptions,BayesInfo,Dynar
 % AUTHOR(S) stephane DOT adjemian AT univ DASH lemans DOT FR
 
 % Declaration of the penalty as a persistent variable.
-persistent penalty
 
-% Initialization of the persistent variable.
-if ~nargin || isempty(penalty)
-    penalty = 1e8;
-    if ~nargin, return, end
-end
-if nargin==1
-    penalty = xparam1;
-    return
-end
+% Persistent variable 'penalty' is used to compute an endogenous penalty to
+% the value 'fval' when various conditions are encountered. These conditions
+% set also 'exit_flag' equal to 0 instead of 1.  It is only when
+% dsge_likelihood() is called by an optimizer called by
+% dynare_estimation_1() that 'exit_flag' is ignored and penalized 'fval' is
+% actually used.  
+% In that case, 'penalty' is properly initialized, at the very end of the
+% present function, by a call to dsge_likelihood() made in
+% initial_estimation_checks(). If a condition triggers exit_flag ==
+% 0, initial_estimation_checks() triggers an error.
+% In summary, an initial call to the present function, without triggering
+% any condition, guarantees that 'penalty' is properly initialized when needed.
+
+persistent penalty
 
 % Initialization of the returned variables and others...
 fval        = [];
diff --git a/matlab/dsge_likelihood_hh.m b/matlab/dsge_likelihood_hh.m
index a77982236..9c54b609e 100644
--- a/matlab/dsge_likelihood_hh.m
+++ b/matlab/dsge_likelihood_hh.m
@@ -41,17 +41,20 @@ function [fval,llik,cost_flag,ys,trend_coeff,info] = dsge_likelihood_hh(xparam1,
 
 
 % Declaration of the penalty as a persistent variable.
-persistent penalty
 
-% Initialization of the persistent variable.
-if ~nargin || isempty(penalty)
-    penalty = 1e8;
-    if ~nargin, return, end
-end
-if nargin==1
-    penalty = xparam1;
-    return
-end
+% Persistent variable 'penalty' is used to compute an endogenous penalty to
+% the value 'fval' when various conditions are encountered. These conditions
+% set also 'exit_flag' equal to 0 instead of 1.  It is only when
+% dsge_likelihood_hh() is called by an newrat() called by
+% dynare_estimation_1() that 'exit_flag' is ignored and penalized 'fval' is
+% actually used.  
+% In that case, 'penalty' is properly initialized, at the very end of the
+% present function, by a call to dsge_likelihood_hh() made in
+% initial_estimation_checks(). If a condition triggers exit_flag ==
+% 0, initial_estimation_checks() triggers an error.
+% In summary, an initial call to the present function, without triggering
+% any condition, guarantees that 'penalty' is properly initialized when needed.
+persistent penalty
 
 % Initialization of the returned variables and others...
 fval        = [];
diff --git a/matlab/initial_estimation_checks.m b/matlab/initial_estimation_checks.m
index 09bf7fea3..3bf52e8e7 100644
--- a/matlab/initial_estimation_checks.m
+++ b/matlab/initial_estimation_checks.m
@@ -42,6 +42,12 @@ if DynareOptions.dsge_var
     [fval,cost_flag,info] = DsgeVarLikelihood(xparam1,DynareDataset,DynareOptions,Model,EstimatedParameters,BayesInfo,DynareResults);
 else
     [fval,cost_flag,ys,trend_coeff,info] = dsge_likelihood(xparam1,DynareDataset,DynareOptions,Model,EstimatedParameters,BayesInfo,DynareResults);
+    if DynareOptions.mode_compute == 5
+        % this call is necessary to initialized persistent variable
+        % 'penalty' in dsge_likelihood_hh
+        [fval,llik,cost_flag,ys,trend_coeff,info] = ...
+            dsge_likelihood_hh(xparam1,DynareDataset,DynareOptions,Model,EstimatedParameters,BayesInfo,DynareResults);
+    end
 end
 
 if info(1) > 0