AFNI Message Board

Dear AFNI users-

We are very pleased to announce that the new AFNI Message Board framework is up! Please join us at:

https://discuss.afni.nimh.nih.gov

Existing user accounts have been migrated, so returning users can login by requesting a password reset. New users can create accounts, as well, through a standard account creation process. Please note that these setup emails might initially go to spam folders (esp. for NIH users!), so please check those locations in the beginning.

The current Message Board discussion threads have been migrated to the new framework. The current Message Board will remain visible, but read-only, for a little while.

Sincerely, AFNI HQ

History of AFNI updates  

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December 08, 2016 05:27PM
Hi AFNI gurus
Can someone let me know the details of the algorithm used to fit the auto-correlation function in 3dFWHMx?
Specifically how was the equation ACF(r) = a * exp(-r*r/(2*b*b)) + (1-a)*exp(-r/c) fitted?
Did you use some kind of a non-linear data fitting algorithm? What were the upper and and lower bounds allowed on the ACF parameters "a", "b" and "c" ?

Thanks a million
Gopi
Subject Author Posted

Algorithm used to fit ACF in 3dFWHMx

Gopi December 08, 2016 05:27PM

Re: Algorithm used to fit ACF in 3dFWHMx

Bob Cox December 08, 2016 07:08PM

Re: Algorithm used to fit ACF in 3dFWHMx

Gopi December 09, 2016 08:47AM