<div dir="ltr"><div dir="ltr"><div dir="ltr"><div dir="ltr"><div dir="ltr">Hi Alessandro,</div><div dir="ltr"><br><div>As explained in the <a href="https://github.com/fieldtrip/fieldtrip/blob/master/ft_preprocessing.m#L55">help </a>of ft_preprocessing, the default filter order can be found in the low level functions:</div><div><div>fieldtrip/preproc/ft_preproc_bandpassfilter.m</div><div>fieldtrip/preproc/ft_preproc_bandstopfilter.m</div><div>fieldtrip/preproc/ft_preproc_highpassfilter.m</div><div>fieldtrip/preproc/ft_preproc_lowpassfilter.m</div></div><div><br></div><div>The filter order means something very different for the Butterworth (i.e. amount of samples used for the input-output recursion) </div><div><a href="https://github.com/fieldtrip/fieldtrip/blob/master/preproc/ft_preproc_bandpassfilter.m#L151">https://github.com/fieldtrip/fieldtrip/blob/master/preproc/ft_preproc_bandpassfilter.m#L151</a><br></div><div><br></div><div>or for the Finite Impulse Response (FIR) filter (i.e. length of the filter kernel).</div><a href="https://github.com/fieldtrip/fieldtrip/blob/master/preproc/ft_preproc_bandpassfilter.m#L235">https://github.com/fieldtrip/fieldtrip/blob/master/preproc/ft_preproc_bandpassfilter.m#L235</a></div><div dir="ltr"><br></div><div>For the ones interested to know more about what that number does for different filters, please check this example script:</div><div><a href="http://www.fieldtriptoolbox.org/example/determine_the_filter_characteristics">http://www.fieldtriptoolbox.org/example/determine_the_filter_characteristics</a><br></div><div><br></div><div>I hope that helps,</div><div><br></div><div>Diego</div><div dir="ltr"><br></div><div dir="ltr"><br><div class="gmail_quote"><div dir="ltr">On Tue, 16 Oct 2018 at 23:13, Alessandro Orticoni <<a href="mailto:alessandro.orticoni@gmail.com">alessandro.orticoni@gmail.com</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div dir="ltr">Dear all,<div><br></div><div>I would like to ask you just a question: which is the default order of the filters implemented by ft_preprocessing? I cannot find it anywhere.</div><div><br></div><div>Thanks a lot,</div><div>Alessandro Orticoni </div></div>
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