[FieldTrip] Channel_selection

[Cristiano Micheli]

Dear Federico il Grande

Allow 'badchstr' to be a cellarray of strings like this:

badchstr = {'label2' 'labe8' ... 'label199'};


Try this:

    chstr = {'all'};

    for i=1:numel(badchstr)

      chstr(i+1) = cellstr(sprintf('-%s ',badchstr{i}));

    end


    cfg = [];

    cfg.channel = chstr;

    dataclean = ft_preprocessing(cfg,data);


Best,

Cristiano


On Wed, Nov 27, 2013 at 11:13 AM, Max Cantor <mcantor at umich.edu> wrote:

> Here is how I do it:
>
> allchan = ft_read_header(dataset);
>
> (preprocess)
>
> allchan.label = [allchan.label; implicitref];
>
> (after artifact rejection/ICA/etc.)
>
> badchan  = ft_channelselection('gui', allchan.label);
>
> This gives me the channel labels for all channels, with the implicitref
> added back in (normally this is removed), then a gui which lets me remove
> bad channels manually after preprocessing/artifact rejection/ICA/etc.
>
> Hope this helps.
>
> Max Cantor
> Research Assistant
> Computational Neurolinguistics Lab
> University of Michigan
>
>
> On Wed, Nov 27, 2013 at 10:46 AM, "Jörn M. Horschig" <
> jm.horschig at donders.ru.nl> wrote:
>
>> Hi Frederico,
>>
>> I think the best solution is to not use fieldtrip but plain matlab
>> function. This is a small example that might help you:
>>
>> >> allchans = {'Fz', 'Cz', 'CPz'};
>> >> badchans = {'Fz', 'Cz'};
>> >> idx = ismember(allchans, badchans)
>>
>> idx =
>>
>>      1     1     0
>>
>> You can then use the idx variable and logical indexing to get the good
>> channels:
>>
>> >> allchans(~idx)
>>
>> ans =
>>
>>     'CPz'
>>
>> And then use cfg.channel = allchans(~idx).
>>
>> Be aware that ismember is a tricky function, because it returns the
>> indices of the first vector as the first return variable and the respective
>> same for the second vector as the second return variable, so order does
>> matter. Just give it a try and play a bit around with it and you'll see.
>>
>> Best,
>> Jörn
>>
>>
>>
>> Federico Grande wrote:
>>
>>> Hello everyone,
>>>
>>> In order to clean a little bit more my measurements, I have developed a
>>> method which detects bad channels, and now, once I have the labels of the
>>> bad channels, I want to give it to ft_preprocessing, but I don't know how.
>>> I've been looking on ft_channelselection, and it seems that there is an
>>> option , by using some like channel={'all','-channel to exclude'}. I have
>>> an array with the labels of this channels that I want to exclude, but I
>>> don't know why, it seems that I am not using it in the proper way. I have
>>> tried  with cfg.channel= {'all','-badSelections'} (badSelections is my
>>> array), and it doesn't work, since after processing, still appear all the
>>> channels in the dat.label.
>>>
>>> Any suggestion?
>>>
>>> Thank you very much!!
>>>
>>> All the best,
>>>
>>> Federico Grande
>>> _______________________________________________
>>> fieldtrip mailing list
>>> fieldtrip at donders.ru.nl
>>> http://mailman.science.ru.nl/mailman/listinfo/fieldtrip
>>>
>>
>>
>> --
>> Jörn M. Horschig
>> PhD Student
>> Donders Institute for Brain, Cognition and Behaviour
>> Centre for Cognitive Neuroimaging
>> Radboud University Nijmegen
>> Neuronal Oscillations Group
>> FieldTrip Development Team
>>
>> P.O. Box 9101
>> NL-6500 HB Nijmegen
>> The Netherlands
>>
>> Contact:
>> E-Mail: jm.horschig at donders.ru.nl
>> Tel:    +31-(0)24-36-68493
>> Web: http://www.ru.nl/donders
>>
>> Visiting address:
>> Trigon, room 2.30
>> Kapittelweg 29
>> NL-6525 EN Nijmegen
>> The Netherlands
>>
>>
>> _______________________________________________
>> fieldtrip mailing list
>> fieldtrip at donders.ru.nl
>> http://mailman.science.ru.nl/mailman/listinfo/fieldtrip
>>
>
>
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