<html xmlns:v="urn:schemas-microsoft-com:vml" xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns:m="http://schemas.microsoft.com/office/2004/12/omml" xmlns="http://www.w3.org/TR/REC-html40"><head><META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=us-ascii"><meta name=Generator content="Microsoft Word 12 (filtered medium)"><style><!--
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</o:shapelayout></xml><![endif]--></head><body lang=EN-US link=blue vlink=purple><div class=WordSection1><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Hi Roy,<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Fieldtrip allows you to create and use your own functions to calculate statistics. What you could also do is adjust the indepsamplesT statistic function (fieldtrip/statfun/ft_statfun_indepsamplesT.m) to suite your needs (E.g. change the Df in line 89). <o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Best,<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Jim<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><div style='border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0in 0in 0in'><p class=MsoNormal><b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>From:</span></b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'> fieldtrip-bounces@science.ru.nl [mailto:fieldtrip-bounces@science.ru.nl] <b>On Behalf Of </b>Roy Cox<br><b>Sent:</b> donderdag 23 januari 2014 16:20<br><b>To:</b> fieldtrip@science.ru.nl<br><b>Subject:</b> [FieldTrip] degrees of freedom<o:p></o:p></span></p></div><p class=MsoNormal><o:p> </o:p></p><div><div><p class=MsoNormal style='margin-bottom:12.0pt'>Hi all,<o:p></o:p></p></div><p class=MsoNormal>I'm using ft_timelockstatistics with indepsamplesT to compare spatial topographies between two groups (n=15 and n=13). The measure I'm interested in has no time dimension, so I basically have one sample per electrode for each subject.<o:p></o:p></p><div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal style='margin-bottom:12.0pt'>This works fine (I get the effects I hoped for). In order to make the statistics 'slightly more valid', however, I need to adjust the degrees of freedom. That is, the data I'm comparing between groups has already had a covariate taken out. So df has to be df-1.<o:p></o:p></p></div><div><p class=MsoNormal style='margin-bottom:12.0pt'>Doesn't look like Fieldtrip allows you to set this in the cfg struct somewhere, so any suggestions where I need to hack?<o:p></o:p></p></div><div><p class=MsoNormal style='margin-bottom:12.0pt'>Thanks,<o:p></o:p></p></div><div><p class=MsoNormal>Roy<br clear=all><o:p></o:p></p></div><div><p class=MsoNormal><br>-- <o:p></o:p></p><p class=MsoNormal style='background:white'><span style='font-family:"Courier New";color:#666666'>Roy Cox, M.Sc. | Brain & Cognition Group | Department of Psychology | University of Amsterdam | </span><span lang=NL style='font-size:10.0pt;font-family:"Courier New";color:#666666'>Weesperplein 4 | 1018 XA Amsterdam</span><span style='font-family:"Courier New";color:#666666'> | the Netherlands | room 3.21 | phone: +31 20 525 6847 | email: <a href="mailto:r.cox@uva.nl" target="_blank">r.cox@uva.nl</a><o:p></o:p></span></p></div></div></div></div></body></html>