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<blockquote type="cite" cite="mid9402194569.9456994021@montclair.edu">
<pre wrap="">I am trying to band pass filter my eeg data between 1 and 30 Hz. I noticed that EEGlab uses a fourier transoform and what appears to be an ideal band pass filter. I have some experience using such a method to filter digital images for stimuli, and found that I get 'ringing' in the image using ideal filter functions. Might this be the case while filtering one dimensional eeg data? Might it be advisable to use a butterworth function? Basically what I am wondering is this: does eeglab use the fourier filter because I do not have matlab's signal processing toolbox? </pre>
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Yes it does. I programmed this filter because it was a better
alternative than no filtering at all for users who do not have the
signal processing toolbox. I observed that with this type of filter the
signal drop-off was not as high as with standard FIR filtering. I do
not know about ringing. The best alternative to it might be to buy the
signal processing toolbox?<br>
<br>
Arno<br>
<div class="moz-signature">-- <br>
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<b><font face="Arial,Helvetica"><font size="+1">Arnaud Delorme, Ph.D.</font></font></b>
<br>
<font face="Arial,Helvetica"><font size="+1"><font color="#3333ff">Swartz
Center for Computational Neuroscience,</font> <font color="#3333ff">INC,
University of San Diego California</font></font></font>
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<font face="Arial,Helvetica"><b>To think upon</b>:</font></p>
<blockquote><dt><font face="Arial,Helvetica"> The hardest work is to go
idle.
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<dd><font face="Arial,Helvetica"><i>Yiddish proverb</i></font></dd>
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