dynare/matlab/doc/DiffuseLikelihood1.html

140 lines
7.0 KiB
HTML

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
"http://www.w3.org/TR/REC-html40/loose.dtd">
<html>
<head>
<title>Description of DiffuseLikelihood1</title>
<meta name="keywords" content="DiffuseLikelihood1">
<meta name="description" content="M. Ratto added lik in output">
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
<meta name="generator" content="m2html &copy; 2003 Guillaume Flandin">
<meta name="robots" content="index, follow">
<link type="text/css" rel="stylesheet" href="../m2html.css">
</head>
<body>
<a name="_top"></a>
<div><a href="../index.html">Home</a> &gt; <a href="index.html">.</a> &gt; DiffuseLikelihood1.m</div>
<!--<table width="100%"><tr><td align="left"><a href="../index.html"><img alt="<" border="0" src="../left.png">&nbsp;Master index</a></td>
<td align="right"><a href="index.html">Index for .&nbsp;<img alt=">" border="0" src="../right.png"></a></td></tr></table>-->
<h1>DiffuseLikelihood1
</h1>
<h2><a name="_name"></a>PURPOSE <a href="#_top"><img alt="^" border="0" src="../up.png"></a></h2>
<div class="box"><strong>M. Ratto added lik in output</strong></div>
<h2><a name="_synopsis"></a>SYNOPSIS <a href="#_top"><img alt="^" border="0" src="../up.png"></a></h2>
<div class="box"><strong>function [LIK, lik] = DiffuseLikelihood1(T,R,Q,Pinf,Pstar,Y,trend,start) </strong></div>
<h2><a name="_description"></a>DESCRIPTION <a href="#_top"><img alt="^" border="0" src="../up.png"></a></h2>
<div class="fragment"><pre class="comment"> M. Ratto added lik in output
stephane.adjemian@cepremap.cnrs.fr [07-19-2004]
Same as DiffuseLikelihoodH1 without measurement error.</pre></div>
<!-- crossreference -->
<h2><a name="_cross"></a>CROSS-REFERENCE INFORMATION <a href="#_top"><img alt="^" border="0" src="../up.png"></a></h2>
This function calls:
<ul style="list-style-image:url(../matlabicon.gif)">
</ul>
This function is called by:
<ul style="list-style-image:url(../matlabicon.gif)">
</ul>
<!-- crossreference -->
<h2><a name="_source"></a>SOURCE CODE <a href="#_top"><img alt="^" border="0" src="../up.png"></a></h2>
<div class="fragment"><pre>0001 <a name="_sub0" href="#_subfunctions" class="code">function [LIK, lik] = DiffuseLikelihood1(T,R,Q,Pinf,Pstar,Y,trend,start)</a>
0002 <span class="comment">% M. Ratto added lik in output</span>
0003 <span class="comment">% stephane.adjemian@cepremap.cnrs.fr [07-19-2004]</span>
0004 <span class="comment">%</span>
0005 <span class="comment">% Same as DiffuseLikelihoodH1 without measurement error.</span>
0006 <span class="keyword">global</span> bayestopt_ options_
0007
0008 mf = bayestopt_.mf;
0009 smpl = size(Y,2);
0010 mm = size(T,2);
0011 pp = size(Y,1);
0012 a = zeros(mm,1);
0013 dF = 1;
0014 QQ = R*Q*transpose(R);
0015 t = 0;
0016 lik = zeros(smpl+1,1);
0017 LIK = Inf;
0018 lik(smpl+1) = smpl*pp*log(2*pi);
0019 notsteady = 1;
0020 crit = options_.kalman_tol;
0021 reste = 0;
0022 <span class="keyword">while</span> rank(Pinf,crit) &amp; t &lt; smpl
0023 t = t+1;
0024 v = Y(:,t)-a(mf)-trend(:,t);
0025 Finf = Pinf(mf,mf);
0026 <span class="keyword">if</span> rcond(Finf) &lt; crit
0027 <span class="keyword">if</span> ~all(abs(Finf(:)) &lt; crit)
0028 <span class="keyword">return</span>
0029 <span class="keyword">else</span>
0030 iFstar = inv(Pstar(mf,mf));
0031 dFstar = det(Pstar(mf,mf));
0032 Kstar = Pstar(:,mf)*iFstar;
0033 lik(t) = log(dFstar) + transpose(v)*iFstar*v;
0034 Pinf = T*Pinf*transpose(T);
0035 Pstar = T*(Pstar-Pstar(:,mf)*transpose(Kstar))*transpose(T)+QQ;
0036 a = T*(a+Kstar*v);
0037 <span class="keyword">end</span>
0038 <span class="keyword">else</span>
0039 lik(t) = log(det(Finf));
0040 iFinf = inv(Finf);
0041 Kinf = Pinf(:,mf)*iFinf; <span class="comment">%% premultiplication by the transition matrix T is removed (stephane)</span>
0042 Fstar = Pstar(mf,mf);
0043 Kstar = (Pstar(:,mf)-Kinf*Fstar)*iFinf; <span class="comment">%% premultiplication by the transition matrix T is removed (stephane)</span>
0044 Pstar = T*(Pstar-Pstar(:,mf)*transpose(Kinf)-Pinf(:,mf)*transpose(Kstar))*transpose(T)+QQ;
0045 Pinf = T*(Pinf-Pinf(:,mf)*transpose(Kinf))*transpose(T);
0046 a = T*(a+Kinf*v);
0047 <span class="keyword">end</span>
0048 <span class="keyword">end</span>
0049 <span class="keyword">if</span> t == smpl
0050 error([<span class="string">'There isn''t enough information to estimate the initial'</span> <span class="keyword">...</span><span class="comment"> </span>
0051 <span class="string">' conditions of the nonstationary variables'</span>]);
0052 <span class="keyword">end</span>
0053 F_singular = 1;
0054 <span class="keyword">while</span> notsteady &amp; t &lt; smpl
0055 t = t+1;
0056 v = Y(:,t)-a(mf)-trend(:,t);
0057 F = Pstar(mf,mf);
0058 oldPstar = Pstar;
0059 dF = det(F);
0060 <span class="keyword">if</span> rcond(F) &lt; crit
0061 <span class="keyword">if</span> ~all(abs(F(:))&lt;crit)
0062 <span class="keyword">return</span>
0063 <span class="keyword">else</span>
0064 a = T*a;
0065 Pstar = T*Pstar*transpose(T)+QQ;
0066 <span class="keyword">end</span>
0067 <span class="keyword">else</span>
0068 F_singular = 0;
0069 iF = inv(F);
0070 lik(t) = log(dF)+transpose(v)*iF*v;
0071 K = Pstar(:,mf)*iF; <span class="comment">%% premultiplication by the transition matrix T is removed (stephane)</span>
0072 a = T*(a+K*v); <span class="comment">%% --&gt; factorization of the transition matrix...</span>
0073 Pstar = T*(Pstar-K*Pstar(mf,:))*transpose(T)+QQ; <span class="comment">%% ... idem (stephane)</span>
0074 <span class="keyword">end</span>
0075 notsteady = ~(max(max(abs(Pstar-oldPstar)))&lt;crit);
0076 <span class="keyword">end</span>
0077 <span class="keyword">if</span> F_singular == 1
0078 error([<span class="string">'The variance of the forecast error remains singular until the'</span> <span class="keyword">...</span>
0079 <span class="string">'end of the sample'</span>])
0080 <span class="keyword">end</span>
0081 reste = smpl-t;
0082 <span class="keyword">while</span> t &lt; smpl
0083 t = t+1;
0084 v = Y(:,t)-a(mf)-trend(:,t);
0085 a = T*(a+K*v);
0086 lik(t) = transpose(v)*iF*v;
0087 <span class="keyword">end</span>
0088 lik(t) = lik(t) + reste*log(dF);
0089
0090
0091 LIK = .5*(sum(lik(start:end))-(start-1)*lik(smpl+1)/smpl);<span class="comment">% Minus the log-likelihood.</span></pre></div>
<hr><address>Generated on Fri 16-Jun-2006 09:09:06 by <strong><a href="http://www.artefact.tk/software/matlab/m2html/">m2html</a></strong> &copy; 2003</address>
</body>
</html>