<html><body><div style="color:#000; background-color:#fff; font-family:times new roman, new york, times, serif;font-size:12pt"><div><span style="font-family: arial, sans-serif; color: rgb(34, 34, 34); font-size: 13px;">Hi,</span><br></div><div style="font-family: 'times new roman', 'new york', times, serif; font-size: 12pt;"><div style="font-family: 'times new roman', 'new york', times, serif; font-size: 12pt;"><div id="yiv173646101"><div><div style="color: rgb(0, 0, 0); background-color: rgb(255, 255, 255); font-family: 'times new roman', 'new york', times, serif; font-size: 12pt;"><div style="font-family: 'times new roman', 'new york', times, serif; font-size: 12pt;"><div style="font-family: 'times new roman', 'new york', times, serif; font-size: 12pt;"><div id="yiv173646101"><div style="color: rgb(0, 0, 0); background-color: rgb(255, 255, 255); font-family: 'times new roman', 'new york', times, serif; font-size: 12pt;"><div style="font-family: arial,
sans-serif; font-size: 13px; color: rgb(34, 34, 34);"><br></div><div style="font-family: arial, sans-serif; font-size: 13px; color: rgb(34, 34, 34);">I have a general query about performance of ICA algorithms.</div><div><font color="#222222" face="arial, sans-serif" size="2">As I know FastICA is trying to estimate sources based
on maximizing the non-gaussianity while, infoamx is trying to estimate the components based on minimizing mutual information between sources. What wonders me is , when I calculated the mutual information between ICs, the averaged mutual information between pairs of ICs in FastICA is lower than ICs estimated by infomax. Additionally when I calculate
the correlation between pairs of the estimated ICs, the averaged absolute correlation between ICs obtained by FastICA is significantly lower than infomax.</font></div><div><font color="#222222" face="arial, sans-serif" size="2">in my opinion this result speculates, the whitening(sphering) step in the infomax is different from FastICA, and it does not perform the same. </font></div><div><font color="#222222" face="arial, sans-serif" size="2">However, when I look at the codes of FastICA and infomax, both have used the same method (and functions) for whitening.</font></div><div style="font-family: arial, sans-serif; font-size: 13px; color: rgb(34, 34, 34);">I appreciate it if anyone can help me through understanding the reason.</div><div style="font-family: arial, sans-serif; font-size: 13px; color: rgb(34, 34, 34);"><br></div><div style="font-family: arial, sans-serif; font-size: 13px; color: rgb(34, 34, 34);">Regards,</div><div style="font-family:
arial, sans-serif; font-size: 13px; color: rgb(34, 34, 34);">Mo</div></div></div><br><br> </div> </div> </div></div></div><meta http-equiv="x-dns-prefetch-control" content="on"><br><br> </div> </div> </div></body></html>