I think it is fine to use f rather than FA.
Peace,
Matt.
-----Original Message-----
From: SUBSCRIBE FSL Anonymous [mailto:[log in to unmask]]
Sent: Monday, May 18, 2009 4:23 AM
To: Matt Glasser; SUBSCRIBE FSL Anonymous
Subject: Re: probtrackx with anistropy to constrain tracking
Hi, Matt and Saad,
Thank you for your answers.
but I cannot understand a true advantage of "anistropy to constrain
tracking"
yet.
>when p(f|Y) = delta(0), the integral is 0, as prob(f<t|Y) is always 0.
>so the tract would never stop.
>when p(f|Y) = delta(1), the integral is 1, as prob(f<t|Y) is always 1.
>so the tract would always stop.
>
>when p(f|Y) is flat, the integral is 1/2, as prob(f<t|Y) = t. so there
>is a 50/50 percent chance to stop.
What meaning does this work have? When should I use it? Is it useful?
If the value of random number is large, the tract would always stop
in spite of white matter areas.
So,
To input a fixed value of f1(cf 0.15, 0.18) and f2(cf 0.05, 0.01) as a
threshold, I modified the program of "anistropy to constrain tracking".
Is it a mistake to use f instead of FA?
thanks,
Kenji
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