Oh, I forgot to say that if you're not running out of RAM by _too
much_ then it might be enough to just use avwroi++ to get rid of the
"edges" of the data, i.e. cut down the FOV in all 3 directions, apply
the same ROI to the 4D data and the mask, and feed that into randomise.
Cheers.
On 29 Jan 2007, at 07:50, Steve Smith wrote:
> Hi,
>
> If you want to do the final stats in SPM then your only option is
> to use SnPM (permutation testing in SPM), as the other inference
> method in SPM (Gaussian field theory) is not valid for data on the
> TBSS skeleton. So yes you can try to feed the all_FA_skeletonised
> data into SnPM; I don't know if this will be more memory efficient
> than randomise - I suspect it may not be, but you can try!
>
> Cheers, Steve.
>
>
> On 29 Jan 2007, at 05:31, Kenneth Qiu wrote:
>
>> Dear Stephen,
>>
>> Thank you for your information. I think I can't afford a new 64-
>> bit machine and thus plan to carry out subsequent analysis using
>> SPM. May I ask whether those *nonlinear_hr* images are in MNI
>> space and ready to perform statistical analysis w/o spatial
>> smoothing? Thank you very much!
>>
>> Best Regards,
>> Deqiang
>>
>>
>> On 1/28/07, Steve Smith <[log in to unmask]> wrote: Hi, please
>> see previous posts on this. For this huge analysis you
>> will need a 64-bit machine, e.g. a 64-bit linux or Mac.
>> Cheers.
>>
>>
>> On 27 Jan 2007, at 09:41, Kenneth Qiu wrote:
>>
>> > Dear FSLexperts,
>> >
>> > I'm currently using TBSS to analyze a DTI dataset with 160 images.
>> > I have been sucessful before the last few steps of tbss_3_postreg.
>> > When it tried to concatenate all *_nonlinear_hr.* images into one
>> > 4D image file using avwmerge, the machine reported "out of memory"
>> > error and the process was killed automatically. With each image
>> > requiring 14M mem, I caculate that I would need around 2.4 G mem,
>> > which is bigger than what I have. Therefore, I want to know whether
>> > there is any way to bypass this obstacle, e.g not using 4D storage.
>> >
>> > Any comment is welcome and appreciated!
>> >
>> > Regards,
>> > Deqiang
>>
>>
>> ---------------------------------------------------------------------
>> ---
>> ---
>> Stephen M. Smith, Professor of Biomedical Engineering
>> Associate Director, Oxford University FMRIB Centre
>>
>> FMRIB, JR Hospital, Headington, Oxford OX3 9DU, UK
>> +44 (0) 1865 222726 (fax 222717)
>> [log in to unmask] http://www.fmrib.ox.ac.uk/~steve
>> ---------------------------------------------------------------------
>> ---
>> ---
>>
>
>
> ----------------------------------------------------------------------
> -----
> Stephen M. Smith, Professor of Biomedical Engineering
> Associate Director, Oxford University FMRIB Centre
>
> FMRIB, JR Hospital, Headington, Oxford OX3 9DU, UK
> +44 (0) 1865 222726 (fax 222717)
> [log in to unmask] http://www.fmrib.ox.ac.uk/~steve
> ----------------------------------------------------------------------
> -----
------------------------------------------------------------------------
---
Stephen M. Smith, Professor of Biomedical Engineering
Associate Director, Oxford University FMRIB Centre
FMRIB, JR Hospital, Headington, Oxford OX3 9DU, UK
+44 (0) 1865 222726 (fax 222717)
[log in to unmask] http://www.fmrib.ox.ac.uk/~steve
------------------------------------------------------------------------
---
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