<html><head></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><div><br></div><div>Hi Sendy,</div><div><br></div><div>You may want to have a look at the following link:</div><div><br></div><div><a href="http://fieldtrip.fcdonders.nl/faq/why_does_my_ica_output_contain_complex_numbers?s[]=component">http://fieldtrip.fcdonders.nl/faq/why_does_my_ica_output_contain_complex_numbers?s[]=component</a></div><div><br></div><div>I assume that your data has been passed through the MaxFilter, which massively reduces the rank of your data, causing the ICA algorithm to spit out complex valued numbers.</div><div>You need to reduce the rank of your data prior to running the component decomposition, to be less that then true rank in your data.</div><div><br></div><div>Best</div><div>Jan-Mathijs</div><br><div><div>On Nov 8, 2013, at 10:47 AM, Sendy Caffarra wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite"><div>Hi,<br><br><br>I'm using Fieldtrip to analyze my Meg data.<br>Actually, I'm trying to reject ocular artifacts by using ICA.<br>I decreased the sample rate to 300 and I performed the ICA analysis as following:<br><br>cfg = [];<br>cfg.resamplefs = 300;<br>cfg.detrend = 'no';<br>data_1_rspl = ft_resampledata(cfg, data_1);<br>%ICA<br>cfg = [];<br>cfg.method = 'runica';<br>comp = ft_componentanalysis(cfg, data_1_rspl);<br><br><br>It worked, but now when I try to visualize the different ICA components using:<br><br>cfg = [];<br>cfg.layout = 'neuromag306mag.lay'; % specify the layout file that should be used for plotting<br>cfg.viewmode = 'component';<br>ft_databrowser(cfg, comp);<br><br>I can see how the waves look like, but I cannot see the topographic distribution of them.<br><br>And Matlab gives me this error:<br><br>??? Error using ==> surf at 78<br>X, Y, Z, and C cannot be complex.<br><br>Error in ==> ft_plot_topo at 251<br> h = surf(Xi-deltax/2,Yi-deltay/2,zeros(size(Zi)), Zi, 'EdgeColor', 'none', 'FaceColor',<br> shading);<br><br>Error in ==> ft_databrowser>redraw_cb at 1850<br> ft_plot_topo(chanx, chany, chanz, 'mask', ...<br><br>Error in ==> ft_databrowser at 671<br>redraw_cb(h);<br><br><br>Could you help me in solving this problem?<br>I also downloaded the latest version of fieldtrip but it still does not work.<br><br>Thanks for your help.<br><br>Sendy<br><br><br>Sendy Caffarra<br>Postdoctoral researcher BCBL<br><a href="http://www.bcbl.eu">www.bcbl.eu</a><br><br>_______________________________________________<br>fieldtrip mailing list<br>fieldtrip@donders.ru.nl<br>http://mailman.science.ru.nl/mailman/listinfo/fieldtrip<br></div></blockquote></div><br><div>
<div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><span class="Apple-style-span" style="border-collapse: separate; color: rgb(0, 0, 0); font-family: Helvetica; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-align: -webkit-auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; font-size: medium; "><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><span class="Apple-style-span" style="border-collapse: separate; color: rgb(0, 0, 0); font-family: Helvetica; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-align: -webkit-auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; font-size: medium; "><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><span class="Apple-style-span" style="border-collapse: separate; color: rgb(0, 0, 0); font-family: Helvetica; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-align: -webkit-auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; font-size: medium; "><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><span class="Apple-style-span" style="border-collapse: separate; color: rgb(0, 0, 0); font-family: Helvetica; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-align: -webkit-auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; font-size: medium; "><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><span class="Apple-style-span" style="border-collapse: separate; color: rgb(0, 0, 0); font-family: Helvetica; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; font-size: medium; "><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><span class="Apple-style-span" style="border-collapse: separate; color: rgb(0, 0, 0); font-family: Helvetica; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; font-size: medium; "><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><span class="Apple-style-span" style="border-collapse: separate; color: rgb(0, 0, 0); font-family: Helvetica; font-size: medium; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; "><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><div>Jan-Mathijs Schoffelen, MD PhD </div><div><br></div><div>Donders Institute for Brain, Cognition and Behaviour, <br>Centre for Cognitive Neuroimaging,<br>Radboud University Nijmegen, The Netherlands</div><div><br></div><div>Max Planck Institute for Psycholinguistics,</div><div>Nijmegen, The Netherlands</div><div><br></div><div><a href="mailto:J.Schoffelen@donders.ru.nl">J.Schoffelen@donders.ru.nl</a></div><div>Telephone: +31-24-3614793</div><div><br></div><div><a href="http://www.hettaligebrein.nl">http://www.hettaligebrein.nl</a></div></div></span></div></span></div></span></div></span></div></span></div></span></div></span></div>
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