<html><head><meta http-equiv="Content-Type" content="text/html charset=utf-8"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class="">Great! Thanks for your response. Lots of useful info, and I may have some follow up questions after I’ve followed some of your suggested steps.<div class=""><div class=""><br class=""></div><div class="">I am wondering though, if eegfilt has such severe problems why is it even still available in eeglab? Or at least why isn’t there a more explicit warning not to use eegfilt (or at least not to use it with the default settings)?</div><div class=""><br class=""></div><div class="">This seems to imply that eegfilt is not necessarily inappropriate. </div><div class=""><br class=""></div><div class="">Thanks,</div><div class=""><br class=""></div><div class="">Mary</div><div class=""><br class=""></div><div class=""><br class=""></div><div class=""><br class=""><div><blockquote type="cite" class=""><div class="">On Apr 16, 2017, at 8:43 AM, Andreas Widmann <<a href="mailto:widmann@uni-leipzig.de" class="">widmann@uni-leipzig.de</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><meta http-equiv="content-type" content="text/html; charset=utf-8" class=""><div dir="auto" class=""><div class=""></div><div class=""><br class=""></div><blockquote type="cite" class=""><div class=""><span class="">We’re replicating another lab’s experiment. They used eegfilt for their data, when we use eegfilt we are able to replicate their effects. However, when we use eegfiltnew we do not. </span><br class=""><span class="">We changed the transition bandwidth to .15 from .25 in eegfiltnew</span></div></blockquote><div class="">You changed that directly in the code? This is actually a bad idea. To only partly change the heuristic for default filter order may have adverse side effects. The .25 parameter only applies to cutoff > 8 Hz (and < Nyquist - 8 Hz) in eegfiltnew anyway. I suggest manually computing filter order from requested transition band width and directly using this filter order in the GUI or CLI. I posted the equation recently on the list.</div><br class=""><blockquote type="cite" class=""><div class=""><span class=""> and the data looks to, again, replicate their effects. This would suggest that a narrower transition bandwidth is yielding better SNR in this case. </span><br class=""><span class=""></span><br class=""><span class="">I have two questions:</span><br class=""><span class=""></span><br class=""><span class="">(1) I realize that the narrow transition bandwidth will increase ripple in the passband</span></div></blockquote><div class="">Where did you read that? This is incorrect. Transition band width is a function of filter order. Ripple is defined by the windowing function. See</div><div class=""><a href="http://home.uni-leipzig.de/~biocog/eprints/widmann_a2015jneuroscimeth250_34.pdf" class="">http://home.uni-leipzig.de/~biocog/eprints/widmann_a2015jneuroscimeth250_34.pdf</a></div><div class="">for a detailed introduction of the concepts.</div><br class=""><blockquote type="cite" class=""><div class=""><span class="">, but is there any other reason why .15 may be problematic vs. .25? </span><br class=""></div></blockquote><div class="">Not problematic, just requires higher filter orders.</div><div class=""><br class=""></div><blockquote type="cite" class=""><div class=""><span class="">(2) Is there any other difference between eegfilt and eegfiltnew besides the transition bandwidth? I couldn’t really tell from my cursory comparison of the functions. </span><br class=""></div></blockquote><div class="">Almost everything. eegfiltnew uses a completely different backend. The frontend was maintained for backward compatibility.</div><div class=""><br class=""></div><div class="">There are two different versions of the old eegfilt function. The older firls-default versions until early 2012 were ok-ish with respect to transition band width but had severe other (related) problems. The later fir1-default versions reduced these problems but transition band width was now actually far from the requested. See</div><div class=""><a href="http://journal.frontiersin.org/article/10.3389/fpsyg.2012.00233/full" class="">http://journal.frontiersin.org/article/10.3389/fpsyg.2012.00233/full</a></div><div class="">for a more details.</div><div class=""><br class=""></div><div class="">I suggest directly comparing the frequency responses of old and new filter to see the effective (!) filter characteristics find out what makes the difference for your data.</div><div class=""><br class=""></div>Best,<div class="">Andreas</div><div class=""><br class=""><blockquote type="cite" class=""><div class=""><span class=""></span><br class=""><span class="">Thanks for your help!!</span><br class=""><span class=""></span><br class=""><span class="">-Mary</span><br class=""><span class=""></span><br class=""><span class="">_______________________________________________</span><br class=""><span class="">Eeglablist page: <a href="http://sccn.ucsd.edu/eeglab/eeglabmail.html" class="">http://sccn.ucsd.edu/eeglab/eeglabmail.html</a></span><br class=""><span class="">To unsubscribe, send an empty email to <a href="mailto:eeglablist-unsubscribe@sccn.ucsd.edu" class="">eeglablist-unsubscribe@sccn.ucsd.edu</a></span><br class=""><span class="">For digest mode, send an email with the subject "set digest mime" to <a href="mailto:eeglablist-request@sccn.ucsd.edu" class="">eeglablist-request@sccn.ucsd.edu</a></span></div></blockquote></div></div></div></blockquote></div><br class=""></div></div></body></html>