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

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Nikin Baidar
May 26, 2022 09:51AM
The help pages for the command `3dTcount` explains that the outliers are defined as:

* The trend and MAD of each time series are calculated.
- MAD = median absolute deviation
= median absolute value of time series minus trend.
* In each time series, points that are 'far away' from the
trend are called outliers, where 'far' is defined by
alpha * sqrt(PI/2) * MAD
alpha = qginv(0.001/N) (inverse of reversed Gaussian CDF)
N = length of time series


I cannot find any mathematical reference to how outliers are defined using the "inverse of reversed Gaussian CDF". Can someone please elaborate on this on how outliers are defined. How the upper and lower bounds are calculated? I would appreciate any help from you folks. Thank you!
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Calculating Outliers

Nikin Baidar May 26, 2022 09:51AM

Re: Calculating Outliers

rick reynolds June 21, 2022 10:10AM