Bug 661 - timef.m: absolute power for wavelet and FFT
timef.m: absolute power for wavelet and FFT
Product: EEGLAB
Classification: Unclassified
Component: General
All All
: P3 normal
Assigned To: Arnaud Delorme
Depends on:
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Reported: 2008-06-13 01:59 PDT by Arnaud Delorme
Modified: 2015-02-20 13:29 PST (History)
2 users (show)

See Also:

Different scaling (right=fft, left=wavelet) (144.44 KB, image/jpeg)
2009-07-02 14:24 PDT, Arnaud Delorme

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Comment 7 Ramon Martinez-Cancino 2015-02-20 13:29:25 PST
Yes, test with newtimef. For wavelets use wavelet factor of 0 or 1 (same as FFT) and make sure you have the same window size for both FFT and wavelets.

Comment 6 Ramon Martinez-Cancino 2014-07-25 13:32:36 PDT
We don't use this function anymore. Should we test this with newtimef??
Comment 5 Arnaud Delorme 2011-09-25 22:45:59 PDT
Yes, still a problem. We should email the eeglablist.

Comment 4 Dev Sarma 2009-11-10 15:29:52 PST
Message for external help posted on wiki web site.
Comment 3 Dev Sarma 2009-10-20 15:39:58 PDT
Still a problem as of October 2009
Comment 2 Arnaud Delorme 2009-07-02 14:28:25 PDT
This is true when we look at the atachement. When plotting the difference from baseline, the scale is similar but when plotting the absolute value, it is very different.

Comment 1 Arnaud Delorme 2009-07-02 14:24:43 PDT
Created attachment 388 [details]
Different scaling (right=fft, left=wavelet)
Description Arnaud Delorme 2008-06-13 01:59:23 PDT
Dear eeglablist subscribers,
I have a question concerning the timef function.
As I want to calculate the absolute power of my data, I set the 'baseline'
parameter to 'NaN'.
Now, first thing that concerns me, I get totally different results using
either FFT or wavelets (freqs from 2-50Hz, FFT yielded values from -25 to
10, wavelet values from 36 to 48).
Besides this, even after reading carefully through previous eeglablist
discussions on this topic, I'm still not shure how to calculate the mean
power (in uV) from the values returned by the function.
I'd appreciate any help, thanks in advance,
Ulrich Pomper