<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=us-ascii">
</head>
<body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class="">
Hi Guillaume,
<div class=""><br class="">
</div>
<div class="">
<div>
<blockquote type="cite" class="">
<div class="">
<div dir="ltr" class="">
<div class="">
<div class="">
<div class="">Following Maris et al. 2007 paper about "Nonparametric testing of coherence difference" I was hesitating regarding the number of degrees of freedom to use in the Z-coherence transform when coherence is calculated over N trials by averaging across
M non-overlapping windows in each of them. Is the df equals to N or N*M then?<br class="">
<br class="">
I am a little confused since in Fieldtrip, this is even 2*N that appears to be used:
<a href="http://fieldtrip.googlecode.com/svn/trunk/statfun/ft_statfun_indepsamplesZcoh.m" target="_blank" class="">
http://fieldtrip.googlecode.com/svn/trunk/statfun/ft_statfun_indepsamplesZcoh.m</a><br class="">
<br class="">
</div>
</div>
</div>
</div>
</div>
</blockquote>
<div><br class="">
</div>
<div>The degrees of freedom is equal to the number of tapers, and because you effectively use non-overlapping tapers (every window corresponds to one taper), your degrees of freedom is N*M.</div>
<div><br class="">
</div>
<div>best,</div>
<div>Eric Maris</div>
<div> </div>
<div><br class="">
</div>
<div><br class="">
</div>
<div><br class="">
</div>
<div><br class="">
</div>
<div><br class="">
</div>
<div><br class="">
</div>
<div><br class="">
</div>
<br class="">
<blockquote type="cite" class="">
<div class="">
<div dir="ltr" class="">
<div class="">
<div class="">Thanks for your time.<br class="">
<br class="">
</div>
Best,<br class="">
<br class="">
</div>
Guillaume<br class="">
</div>
<br class="">
<br class="">
_______________________________________________<br class="">
fieldtrip mailing list<br class="">
<a href="mailto:fieldtrip@donders.ru.nl" class="">fieldtrip@donders.ru.nl</a><br class="">
http://mailman.science.ru.nl/mailman/listinfo/fieldtrip</div>
</blockquote>
</div>
<br class="">
</div>
</body>
</html>