<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<meta content="text/html;charset=ISO-8859-1" http-equiv="Content-Type">
</head>
<body bgcolor="#ffffff" text="#000000">
Yossi Arzouan wrote:
<blockquote cite="mid20060319120714.2712.qmail@web53202.mail.yahoo.com"
type="cite">
<div class="MsoNormal" style="margin: 0in 0in 0pt;"><font
face="Times New Roman" size="3">Hi </font></div>
<div class="MsoNormal" style="margin: 0in 0in 0pt;"><o:p><font
face="Times New Roman" size="3"> </font></o:p></div>
<div class="MsoNormal" style="margin: 0in 0in 0pt;"><o:p></o:p> </div>
<div class="MsoNormal" style="margin: 0in 0in 0pt;"><font
face="Times New Roman" size="3">1. Is there any function in eeglab
that calculate Phase coherence?</font></div>
</blockquote>
Yes, this is the crossf function that calculate (by default) the phase
coherence between two variables.<br>
<blockquote cite="mid20060319120714.2712.qmail@web53202.mail.yahoo.com"
type="cite">
<div class="MsoNormal" style="margin: 0in 0in 0pt;"><font
face="Times New Roman" size="3"> </font></div>
<div class="MsoNormal" style="margin: 0in 0in 0pt;"><o:p><font
face="Times New Roman" size="3"> </font></o:p><font size="3"><font
face="Times New Roman">2. Using crossf, to evaluate coherence between
to signals (x1,x2 ) that share one frequency (fr1) result in a coh
value equally to 1 for all frequencies , <span style=""> </span>s!
houldn’t that result in coh = 1 <span style=""> </span>only for fr1 <span
style=""> </span>? <span style=""><br>
</span></font></font></div>
</blockquote>
If the coherence value is 1, it means that the two signal are
identical. It then depends on how you constructed your signal. See below<br>
<br>
a = rand(1,1000);<br>
b = rand(1,1000);<br>
afft = fft(a);<br>
bfft = fft(b);<br>
bfft(100:300) = afft(100:300); % afft contain a "miror power image" of
itself (aff(2:500).^2 is the same as afft(end:-1:502).^2), so the code
below is necessary<br>
bfft(702:902) = afft(702:902);<br>
aa = ifft(afft);<br>
bb = ifft(bfft);<br>
figure; crossf(aa,bb, 100, [-500 500], 100);<br>
<br>
You will see a "band" of coherence = 1 at 20Hz<br>
<br>
Best,<br>
<br>
Arno<br>
<blockquote cite="mid20060319120714.2712.qmail@web53202.mail.yahoo.com"
type="cite">
<div class="MsoNormal" style="margin: 0in 0in 0pt;"><o:p><font
face="Times New Roman" size="3"> </font></o:p></div>
<div class="MsoNormal" style="margin: 0in 0in 0pt;"><font
face="Times New Roman" size="3">Yossi</font></div>
<div class="MsoNormal" style="margin: 0in 0in 0pt;"><o:p><font
face="Times New Roman" size="3"> </font></o:p></div>
<p> </p>
<hr size="1">Yahoo! Mail<br>
Bring photos to life! <a
href="http://pa.yahoo.com/*http://us.rd.yahoo.com/evt=39174/*http://photomail.mail.yahoo.com">New
PhotoMail </a> makes sharing a breeze.
<pre wrap="">
<hr size="4" width="90%">
_______________________________________________
eeglablist mailing list <a class="moz-txt-link-abbreviated" href="mailto:eeglablist@sccn.ucsd.edu">eeglablist@sccn.ucsd.edu</a>
Eeglablist page: <a class="moz-txt-link-freetext" href="http://sccn.ucsd.edu/eeglab/eeglabmail.html">http://sccn.ucsd.edu/eeglab/eeglabmail.html</a>
To unsubscribe, send an empty email to <a class="moz-txt-link-abbreviated" href="mailto:eeglablist-unsubscribe@sccn.ucsd.edu">eeglablist-unsubscribe@sccn.ucsd.edu</a></pre>
</blockquote>
<br>
</body>
</html>