[FieldTrip] How to obtain the frequency power spectrum of ica components?

[Eelke Spaak]

Hi Ashley,

In addition to Roey's remark, in general I would say it is not a good
idea to explicitly modify the xxx.cfg.previous structure. Just create
a new cfg from scratch for each FT function call:

cfg = [];
cfg.method = 'mtmfft';
cfg.foi = ....
etc.

compfreq = ft_freqanalysis(cfg, comp);

Best,
Eelke

On 6 August 2014 09:07, Roey Schurr <roeysc at gmail.com> wrote:
> Dear Ashly,
>
> I'm trying to recreate the error you got, but I couldn't.
> Did you specify the method? Try using
>       comp.cfg.previous.method = 'mtmfft';
>
> When I run ft_freqanalysis using the mtmfft method on the comp structure I
> get from the ICA tutorial, everything seems to work fine. Did  you try
> running the same function on a tutorial structure?
>
> Best.
> Roey
>
>
> On Wed, Aug 6, 2014 at 8:12 AM, Ashley Greene <agreene24 at gmail.com> wrote:
>>
>> Hello,
>>
>> I'm somewhat new to ft, so forgive me if this is a seemingly trivial
>> question.
>> I ran runica on ft preprocessed MEG data, but I also want to see the
>> frequency power spectrum of the components. I've tried using freqanalysis on
>> the components in the following manner:
>>
>>
>> comp.cfg.previous.tapsmofrq=4;
>> comp.cfg.previous.foi=[0:2:30];
>> comp.cfg.previous.t_ftimwin = 5./comp.cfg.previous.foi;
>> comp.cfg.previous.toi=[-0.5:0.05:1.5];
>> comp.cfg.previous.channel='all';
>>
>> [freqcomp] = ft_freqanalysis(comp.cfg.previous, comp)
>>
>>
>> // but the errors I receive are as follows:
>>
>>
>> Warning: Input arguments must be scalar.
>> > In specest/private/ft_preproc_polyremoval at 57
>>   In ft_specest_mtmfft at 66
>>   In ft_freqanalysis at 526
>> ??? For colon operator with char operands, first and last operands must be
>> char.
>>
>> Error in ==> ft_preproc_polyremoval at 58
>> for i = 0:order
>>
>> Error in ==> ft_specest_mtmfft at 66
>>   dat = ft_preproc_polyremoval(dat, polyorder, 1, ndatsample);
>>
>> Error in ==> ft_freqanalysis at 526
>>         [spectrum,ntaper,foi] = ft_specest_mtmfft(dat, time, 'taper',
>> cfg.taper, options{:}, 'feedback', fbopt);
>>
>> // Is using freqanalysis on the components possible? If so, what needs to
>> be modified in order to employ it? If not, is there another method to
>> outputting the frequency power spectrum of ica components?
>>
>> Thanks,
>>
>> Ashley
>>
>>
>>
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>
>
>
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