Dear Kenneth,
It shouldn't matter, should it? The two operations (averaging and
multiplication by a matrix inverse) should yield the same result regardless
of order.
Sincerely,
Eric
----- Original Message -----
From: "dqqiu" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Thursday, January 05, 2006 3:08 AM
Subject: [SPM] DTI tensor calculation
> Dear SPMers:
> I'm analyzing a normative dti data set imaged with 6 gradient directions
> and 4 repetitions. For calculation of the tensor and FA, I wonder
> whether it is better to average over repetition first and then solve 6
> linear equations, or just to put all together and solve overdetermined
> linear equations using Least Square Estimation.
>
> I know the question is not really of SPM, but I don't know other place
> to ask.
> Any suggestion is appreciated!
>
> Thanks in advance.
>
> Regards,
> Kenneth
> The University of Hong Kong.
>
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