Hi
Not sure I fully understand what you are doing.
Are you saying that you are comparing:
1. Seed=2 ROIs, Waypoints=the same 2 rois, mode=single mask
2. Seed=2 ROIs, Mode=multiple masks
I think (1) and (2) should in theory give you the same results, but there will be slight differences due to the random number generator, as the voxels in the seeds from (1) and (2) are not processed in the same order.
Cheers
Saad
On 30 Jul 2012, at 09:37, SUBSCRIBE FSL Jay wrote:
> Hello,
>
> I am performing probabilistic tracking using 2 ROI's or masks using Multiple masks and Waypoint masks options separately. I would like to know the difference between these two options.
>
> As per the definitions,
> Multiple masks: This option repeatedly samples tracts from every seed mask in a list, and retains only those tracts that pass through at least one of the other seed masks.
> Waypoint masks:Tracts that do not pass through ALL these masks will be discarded from the calculation of the connectivity distribution.
>
> As per the definitions i understood that both the options mean the same in case of 2 masks, but i see slightly different results when i perfromed tracking. Can you please tell me the reason for this?
>
> BW
> Jay
>
--
Saad Jbabdi
University of Oxford, FMRIB Centre
JR Hospital, Headington, OX3 9DU, UK
(+44)1865-222466 (fax 717)
www.fmrib.ox.ac.uk/~saad
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