Mercurial > hg > camir-aes2014
diff toolboxes/FullBNT-1.0.7/KPMstats/student_t_prob.m @ 0:e9a9cd732c1e tip
first hg version after svn
author | wolffd |
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date | Tue, 10 Feb 2015 15:05:51 +0000 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/toolboxes/FullBNT-1.0.7/KPMstats/student_t_prob.m Tue Feb 10 15:05:51 2015 +0000 @@ -0,0 +1,19 @@ +function p = student_t_pdf(X, mu, lambda, alpha) +% STUDENT_T_PDF Evaluate the multivariate student-t distribution at a point +% p = student_t_pdf(X, mu, lambda, alpha) +% +% Each column of X is evaluated. +% See Bernardo and Smith p435. + +k = length(mu); +assert(size(X,1) == k); +[k N] = size(X); +numer = gamma(0.5*(alpha+k)); +denom = gamma(0.5*alpha) * (alpha*pi)^(k/2); +c = (numer/denom) * det(lambda)^(0.5); +p = c*(1 + (1/alpha)*(X-mu)'*lambda*(X-mu))^(-(alpha+k)/2); % scalar version +%m = repmat(mu(:), 1, N); +%exponent = sum((X-m)'*lambda*(X-m), 2); % column vector +%p = c*(1 + (1/alpha)*exponent).^(-(alpha+k)/2); + +keyboard