[FieldTrip] help

[Max Cantor]

I'm having this issue as well, only with EEG data, and at resamplefs = 150.
I've added '-refchan' to my cfg.channel for ft_componentanalysis, and also
set path for EEGlab toolbox, but the issue persists. Any help would be
greatly appreciated.

Thank you,
Max


On Fri, Nov 8, 2013 at 5:14 AM, Stephen Whitmarsh <
stephen.whitmarsh at gmail.com> wrote:

> Hi Sendy, JM,
>
> In addition, that error also happens (or used to, at least) when you have
> not selected MEG as channels, therefor applying ICA e.g. also on your EOG
> channels etc. as well.
>
> Cheers,
> Stephen
>
>
>
>
> On 8 November 2013 11:08, jan-mathijs schoffelen <
> jan.schoffelen at donders.ru.nl> wrote:
>
>>
>> Hi Sendy,
>>
>> You may want to have a look at the following link:
>>
>>
>> http://fieldtrip.fcdonders.nl/faq/why_does_my_ica_output_contain_complex_numbers?s[]=component
>>
>> 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.
>> 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.
>>
>> Best
>> Jan-Mathijs
>>
>> On Nov 8, 2013, at 10:47 AM, Sendy Caffarra wrote:
>>
>> Hi,
>>
>>
>> I'm using Fieldtrip to analyze my Meg data.
>> Actually, I'm trying to reject ocular artifacts by using ICA.
>> I decreased the sample rate to 300 and I performed the ICA analysis as
>> following:
>>
>> cfg = [];
>> cfg.resamplefs = 300;
>> cfg.detrend    = 'no';
>> data_1_rspl = ft_resampledata(cfg, data_1);
>> %ICA
>> cfg            = [];
>> cfg.method = 'runica';
>> comp           = ft_componentanalysis(cfg, data_1_rspl);
>>
>>
>> It worked, but now when I try to visualize the different ICA components
>> using:
>>
>> cfg                 = [];
>> cfg.layout          = 'neuromag306mag.lay'; % specify the layout file
>> that should be used for plotting
>> cfg.viewmode        = 'component';
>> ft_databrowser(cfg, comp);
>>
>> I can see how the waves look like, but I cannot see the topographic
>> distribution of them.
>>
>> And Matlab gives me this error:
>>
>> ??? Error using ==> surf at 78
>> X, Y, Z, and C cannot be complex.
>>
>> Error in ==> ft_plot_topo at 251
>>  h = surf(Xi-deltax/2,Yi-deltay/2,zeros(size(Zi)), Zi, 'EdgeColor',
>> 'none', 'FaceColor',
>>  shading);
>>
>> Error in ==> ft_databrowser>redraw_cb at 1850
>>      ft_plot_topo(chanx, chany, chanz, 'mask', ...
>>
>> Error in ==> ft_databrowser at 671
>> redraw_cb(h);
>>
>>
>> Could you help me in solving this problem?
>> I also downloaded the latest version of fieldtrip but it still does not
>> work.
>>
>> Thanks for your help.
>>
>> Sendy
>>
>>
>> Sendy Caffarra
>> Postdoctoral researcher BCBL
>> www.bcbl.eu
>>
>> _______________________________________________
>> fieldtrip mailing list
>> fieldtrip at donders.ru.nl
>> http://mailman.science.ru.nl/mailman/listinfo/fieldtrip
>>
>>
>>     Jan-Mathijs Schoffelen, MD PhD
>>
>> Donders Institute for Brain, Cognition and Behaviour,
>> Centre for Cognitive Neuroimaging,
>> Radboud University Nijmegen, The Netherlands
>>
>> Max Planck Institute for Psycholinguistics,
>> Nijmegen, The Netherlands
>>
>> J.Schoffelen at donders.ru.nl
>> Telephone: +31-24-3614793
>>
>> http://www.hettaligebrein.nl
>>
>>
>> _______________________________________________
>> fieldtrip mailing list
>> fieldtrip at donders.ru.nl
>> http://mailman.science.ru.nl/mailman/listinfo/fieldtrip
>>
>
>
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