comparison toolboxes/FullBNT-1.0.7/KPMstats/student_t_logprob.m @ 0:e9a9cd732c1e tip

first hg version after svn

+function L = log_student_pdf(X, mu, lambda, alpha)
+% LOG_STUDENT_PDF Evaluate the log of the multivariate student-t distribution at a point
+% L = log_student_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);
+logc = gammaln(0.5*(alpha+k)) - gammaln(0.5*alpha) - (k/2)*log(alpha*pi) + 0.5*log(det(lambda));
+middle = (1 + (1/alpha)*(X-mu)'*lambda*(X-mu)); % scalar version
+L = logc - ((alpha+k)/2)*log(middle);