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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 David,<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'>The problem is with specifying cfg.statistics = ‘diff’. the ft_xxxstats function work by ‘eval’-ing the content of cfg.statistics. Thus, it runs the built-in Matlab function ‘diff’, which is not defined for structs such as FT-data variables, but only for matrices (and cells?). <o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'>I saw there is also a ft_statfun_diff, which is probably the one you were aiming to use. The problem is that internally, the private function ft_getuserfun is checking first for the existence of ‘diff’, before it even comes to considering ‘ft_statfun_diff’. Long story short, you can most likely solve your problem by specifying ‘ft_statfun_diff’ instead of ‘diff’, and the FT guys should think about what to do with ft_getuserfun.<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'>All the best,<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'>Jörn<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><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><b><span style='font-size:9.0pt;font-family:"Verdana",sans-serif;color:#1F497D;mso-fareast-language:NL'>--</span></b><b><span style='font-size:9.0pt;font-family:"Verdana",sans-serif;color:#255A9E;mso-fareast-language:NL'><br>Jörn M. Horschig, PhD</span></b><span style='font-size:9.0pt;font-family:"Verdana",sans-serif;color:#626264;mso-fareast-language:NL'>, Software Engineer<br><a href="http://www.artinis.com/" target="_blank"><span style='color:#626264'>Artinis Medical Systems</span></a> | +31 481 350 980 </span><b><span style='font-size:9.0pt;font-family:"Verdana",sans-serif;color:#255A9E;mso-fareast-language:NL'><o:p></o:p></span></b></p></div><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'><o:p> </o:p></span></p><div><div style='border:none;border-top:solid #E1E1E1 1.0pt;padding:3.0pt 0in 0in 0in'><p class=MsoNormal><b><span style='font-size:11.0pt;font-family:"Calibri",sans-serif'>From:</span></b><span style='font-size:11.0pt;font-family:"Calibri",sans-serif'> fieldtrip-bounces@science.ru.nl [mailto:fieldtrip-bounces@science.ru.nl] <b>On Behalf Of </b>David Pedrosa<br><b>Sent:</b> Tuesday, March 1, 2016 16:22<br><b>To:</b> fieldtrip@science.ru.nl<br><b>Subject:</b> [FieldTrip] Question on coherence stats at sensor level<o:p></o:p></span></p></div></div><p class=MsoNormal><o:p> </o:p></p><div><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Tahoma",sans-serif;color:black'>Dear list, <br><br>I running analyses on the sensor level with EMG-EEG coherence data and I ran into some problems. Basically my intention is to compare the corticomuscular coherence at rest versus during an activation task. For that, according to some older posts and literature, I computed the Z-transformed coherence (after using ft_connectivityanalyses, I manually transformed the cohspctrm data with respect to the dof) which I want to test with a permutation test. Now, when it comes to computing the stats, it gives me the error >> Function 'diff' is not supported for class 'struct'. << Would it be more reasonable using another function? Or does anyone have an idea where my problem could be or what I should do instead?<br><br>Here's the used code I use:<br><br> %% for loop normalizing coherence manually and creating 0-coherence data... <br> coh_diff{1,1} = coh_diff_condition{1,1}.cohspctrm = (atanh(x1) - ...<br> coh_diff_null{1,1}.cohspctrm(:) = 0;<br><br> cfg = [];<br> cfg.channel = {'EEG' 'xEDC'};<br> cfg.parameter = 'cohspctrm';<br> cfg.method = 'montecarlo';<br> cfg.statistic = 'diff';<br> cfg.tail = 0;<br> cfg.clustertail = 0;<br> cfg.alpha = .025;<br> cfg.numrandomization = 500;<br> <br> cfgl = [];<br> cfgl.layout = 'brainamp.sfp';<br> cfg.layout = ft_prepare_layout(cfgl);<br> <br> cfg.computestat = 'yes';<br> cfg.correctm = 'cluster';<br> cfg.clusteralpha = .05;<br> cfg.clusterstatistic = 'maxsum';<br> cfg.minnbchan = 2;<br> <br> cfgn = [];<br> cfgn.method = 'distance';<br> cfgn.neighbourdist = 40; %in mm<br> cfg.neighbours = ft_prepare_neighbours(cfgn,data_epoched_wo);<br> <br> design = zeros( 2,2*numel(coh_diff));<br> design(1,:) = [1:numel(coh_diff), 1:numel(coh_diff_null)];<br> design(2,1:numel(coh_diff)) = 1;<br> design(2,numel(coh_diff)+1:numel(coh_diff)+numel(coh_diff_null)) = 2;<br> <br> cfg.design = design;<br> cfg.ivar = 1;<br> cfg.uvar = 2;<br> [stat] = ft_freqstatistics(cfg, coh_diff{1,1}, coh_diff{1,2}, ..., coh_diff_null{1,12};<br><br>Thanks for your help.<br>Best,<br>David<o:p></o:p></span></p><div><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Tahoma",sans-serif;color:black'><o:p> </o:p></span></p><div><div><div><div><div><div class=MsoNormal align=center style='text-align:center'><span style='font-size:10.0pt;font-family:"Tahoma",sans-serif;color:black'><hr size=2 width="100%" align=center></span></div><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Tahoma",sans-serif;color:#003366'>Dr. David Pedrosa<br><br>Clinical Research Fellow<o:p></o:p></span></p><div><div><div><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Tahoma",sans-serif;color:#003366'>Medical Research Council Brain Network Dynamics Unit at the University of Oxford<br>Nuffield Department of Clinical Neurosciences<o:p></o:p></span></p></div><div><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Tahoma",sans-serif;color:#003366'>University of Oxford<o:p></o:p></span></p></div><div><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Tahoma",sans-serif;color:#003366'>Level 6, West Wing<o:p></o:p></span></p></div><div><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Tahoma",sans-serif;color:#003366'>John Radcliffe Hospital, OX3 9DU<o:p></o:p></span></p></div></div></div><p class=MsoNormal><u><span lang=DE style='font-size:10.0pt;font-family:"Tahoma",sans-serif;color:#003366'>Tel:</span></u><span lang=DE style='font-size:10.0pt;font-family:"Tahoma",sans-serif;color:#003366'> +44 (0)1865 572490<br><u>E-Mail:</u> </span><span style='font-size:10.0pt;font-family:"Tahoma",sans-serif;color:#333333'><a href="mailto:david.pedrosa@ndcn.ox.ac.uk"><span lang=DE>david.pedrosa@ndcn.ox.ac.uk</span></a></span><span lang=DE style='font-size:10.0pt;font-family:"Tahoma",sans-serif;color:#333333'><br></span><span lang=DE style='font-size:10.0pt;font-family:"Tahoma",sans-serif;color:black'><br></span><span style='font-size:10.0pt;font-family:"Tahoma",sans-serif;color:black'><a href="https://owa.nexus.ox.ac.uk/owa/redir.aspx?C=E40BwPuNq0uXQGSOPDW39AmtYlwBR9IIjsI0PRu9uuTE46jeZnqjmG6XP02rBAUiF1EnCJtn3UU.&URL=http%3a%2f%2fwww.mrcbndu.ox.ac.uk%2f" target="_blank"><span lang=DE>http://www.mrcbndu.ox.ac.uk/</span></a></span><span lang=DE style='font-size:10.0pt;font-family:"Tahoma",sans-serif;color:black'><o:p></o:p></span></p></div></div></div></div></div></div></div></div></body></html>