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vb_log_det

PURPOSE

Log( det(sxx) ) for Positive definite matrix

SYNOPSIS

function d = vb_log_det(sxx)

DESCRIPTION

 Log( det(sxx) ) for Positive definite matrix

 Copyright (C) 2011, ATR All Rights Reserved.
 License : New BSD License(see VBMEG_LICENSE.txt)

CROSS-REFERENCE INFORMATION

This function calls:

This function is called by:

vbmeg_ard_estimate25_3 Algorithm for jointly estimating source activities and interactions.
vbmeg_ard_estimate2 Variational Bayes estimation for MEG.
vbmeg_ard_estimate4 Variational Bayes estimation for MEG.
vbmeg_current_filter_z Calculate Hierarchical Bayesian inverse filter
vbmeg_multi_fmri Bayesian Wiener estimation for MEG.
vbmeg_current_filter_z_meeg Calculate Hierarchical Bayesian inverse filter for MEG+EEG

SOURCE CODE

0001 function    d = vb_log_det(sxx)
0002 % Log( det(sxx) ) for Positive definite matrix
0003 %
0004 % Copyright (C) 2011, ATR All Rights Reserved.
0005 % License : New BSD License(see VBMEG_LICENSE.txt)
0006 
0007 % Gauss の消去法による三角行列因子
0008 
0009 [L,U]    = lu(sxx);
0010 eig_val = abs( diag(U) );
0011 
0012 d        = sum( log( eig_val ) );