Hi - you cannot simply average V1 vectors - I'm afraid it doesn't work
like that. One option is to average the tensor components and re-
derive the eigenvectors - there will be tools making that all easy in
the upcoming release - for now, you'll probably need to work that out
(e.g. in matlab) for yourself - sorry!
Cheers.
On 24 Apr 2008, at 08:18, Juergen Haenggi wrote:
> Dear FSL experts
>
> I tried to visualize the mean V1 vector of a group but there is no
> colours
> (RGB). I registered the V1 vector images and the FA images of all
> subjects
> using FLIRT and then averaged them. When loading the mean FA image
> in FSL
> view and overlaid the mean V1 vector image, no colours are visible.
> When
> doing the same with a single subject everything works fine.
>
> When I used the line option to show the V1 vector of the mean image
> it seems
> that there is a regular pattern which I do not understand.
>
> What is wrong?
>
> Thanks in advance
> Best regards
> Juergen
>
> PS: sorry, I could not attach the images because there is a limit of
> 50 kB
> for the FSL mailing list
>
>
> -----------------------------------------------------------
> Juergen Haenggi
> Ph.D. (Dr. des.)
> Division of Neuropsychology
> Institute of Psychology
> University of Zurich
> Binzmuehlestrasse 14, PO Box 25
> 8050 Zurich, Switzerland
> 0041 44 635 73 97 (phone office)
> 0041 76 445 86 84 (phone mobile)
> 0041 44 635 74 09 (fax office)
> BIN 4.D.04 (office room number)
> [log in to unmask] (email)
> http://www.psychologie.uzh.ch/neuropsy/ (website)
> http://www.juergenhaenggi.ch (private website)
> -----------------------------------------------------------
>
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Stephen M. Smith, Professor of Biomedical Engineering
Associate Director, Oxford University FMRIB Centre
FMRIB, JR Hospital, Headington, Oxford OX3 9DU, UK
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