<html><head></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; ">Hi Davide,<div><br></div><div>If you pad up to 10 seconds, you may change the filterfreqs into:</div><div><br></div><div>filterfreqs = [49:0.1:51 99:0.1:101 149:0.1:151].</div><div><br></div><div>Notice the 0.1, rather than the 1. This is because a 10-second segment of data has an intrinsic frequency resolution of 0.1 Hz.</div><div><br></div><div>Note that this may make the code rather slow to run. Wouldn't it more sensible then to use a bsfilter?</div><div><br></div><div>Best,</div><div><br></div><div>JM</div><div><br><div><div>On Oct 4, 2011, at 3:05 PM, Davide Rivolta wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite"><div> </div>
<div>Dear all,</div>
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<div>I am trying to get rid of the power line noise. I use the dftfilter as indicated on the website.</div>
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<div>This works very well for most of the subjects. However, for some of them, I still get the noise.</div>
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<div>My trials have a different lenght: between 500 ms until 3 seconds. </div>
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<div>This is the script I used. </div>
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<div> filterfreqs = [49:1:51 99:1:101 149:1:151];</div>
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<div> cfg.dftfilter = 'yes'; <br> cfg.dftfreq = filterfreqs; <br> cfg.padding = 10;<br> <br> dataprepro_syn = ft_preprocessing(cfg);</div>
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<div>The pad of 10 is the same as another already published study that used the same task.</div>
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<div>Attached is a picture of the problem (blu is baseline, red is stimulus). This is the result of multitepering (dpss).</div>
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<div>Thanks for your help,</div>
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<div>Davide</div>
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<div><br clear="all"> </div>
<span><FMA14_power_spectra1.png></span>_______________________________________________<br>fieldtrip mailing list<br><a href="mailto:fieldtrip@donders.ru.nl">fieldtrip@donders.ru.nl</a><br>http://mailman.science.ru.nl/mailman/listinfo/fieldtrip</blockquote></div><br><div>
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