Dear AC,
Dtifit is NOT limited to up to 256 directions (I just ran one with
260!).
I think what might have happened in your case is the absence of a
carriage return at the end of your bvals file.
Could you check if that solves your problem?
Cheers,
Saad.
On 19 Jan 2009, at 09:35, A.Crippa wrote:
> dear everybody,
> I found there is an upper limit on the number of gradients
> directions that FSL (i.e. DTIFIT) is able to handle.
>
> In my last post, "[FSL] Fdt (DTIFIT) & NEWMAT error" I asked around
> about a 'NEWMAT::IndexException' error appearing when I run DTIFIT
> on a scan.
>
> This scan was taken with 256 gradient directions.
> Then I discard half of the gradients directions (using fslroi on the
> DWI data and considering only the first 124 directions) everything
> worked out fine.
>
> I don't know what's the upper limit, but apparently it's between 125
> and 256.
>
> Greetings
> AC
>
Saad Jbabdi
Oxford University FMRIB Centre
JR Hospital, Headington, OX3 9DU, UK
+44 (0) 1865 222545 (fax 717)
www.fmrib.ox.ac.uk/~saad
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