[FieldTrip] Combine Grand Average

[Stephen Politzer-Ahles]

Hi Mark,

Do you mean to combine multiple conditions into a single condition? For
that I'm not sure of a built-in function that can do this using grand
averages; you might need to re-do ft_timelockanalysis for the new condition
and then make new grand averages. Since it's possible that a given subject
has more trials contributing to her average for condition A than for
condition B, simply averaging the two condition averages together might not
be accurate.

Best,
Steve Politzer-Ahles

Message: 2
> Date: Mon, 19 Mar 2012 11:37:47 +0100
> From: Eelke Spaak <eelke.spaak at donders.ru.nl>
> To: Email discussion list for the FieldTrip project
>        <fieldtrip at donders.ru.nl>
> Subject: Re: [FieldTrip] Combine Grand Average
> Message-ID:
>        <CABPNLUoTApRzDeyZGvWFfwJjxQcE_QgTwf+pRJcy-jjh+_E7iA at mail.gmail.com
> >
> Content-Type: text/plain; charset=ISO-8859-1
>
> Hi Mark,
>
> I am not entirely sure, but I think ft_appendtimelock might be what
> you are looking for. If not, you could probably also just append the
> timelocked information 'by hand':
>
> tl_combined = tl1;
> tl_combined.individual = [tl1.individual; tl2.individual];
>
> But be aware that this could get messy, and you then need to make sure
> the .avg and other fields are still consistent. So, if at all
> possible, stick to ft_appendtimelock :)
>
> Best,
> Eelke
>
> On 16 March 2012 18:05, Mark Noordenbos <mark.noordenbos at gmail.com> wrote:
> > Hi,
> >
> > I'm looking for a function that combines two timelocked Grand Averages
> > (keeping the 'subj_chan_time' dimord).
> > I have for several conditions seperate Grand Averages, but now I need to
> > combine some of them into a new Grand Average while keeping the
> individual
> > data.
> >
> > Does Fieldtrip has a buit-in function to do this?
> >
> > When just calculating the mean, one dimension ('subj' or 'chan' or
> 'time')
> > is always lost.
> >
> > Thanks,
> > Mark
> >
> >
> > --
> > Mark Noordenbos, MSc
> >
> > Radboud University Nijmegen
> > Behavioural Science Institute
> >
> > P.O. Box 9104, Room A05.36
> > 6500 HE Nijmegen
> > The Netherlands
> >
> > Email: m.noordenbos at bsi.ru.nl
> > Telephone: +31 24 3612070
> > Fax:? ? ? ? ? +31 24 3616211
> >
> > http://www.ru.nl
> >
> >
> > _______________________________________________
> > fieldtrip mailing list
> > fieldtrip at donders.ru.nl
> > http://mailman.science.ru.nl/mailman/listinfo/fieldtrip
>
>
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