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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Bob Cox
February 20, 2009 09:50AM
The FDR conversion via the 'new' method and the 'old' method use very different internal data structures for sorting the p-values -- and only the 'old' software has the printing out ('-list') option implemented. Basically, 3dFDR is 2 separate programs combined into 1 -- the 'old' program, which can be slow, and the 'new' program, which can be much faster for high resolution datasets.

It is very important to use a brain mask to avoid trying to compute q-values on trivial values from outside the brain. Otherwise, the q-values will be larger than they should be.

For some explanation of how p-values are converted to q-values, see
[afni.nimh.nih.gov]
In particular, slide #4.

It is hard to say why your t-values didn't "survive" the conversion to q-values, since I don't have your data.

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Subject Author Posted

3dFDR and -list function

Yuhan February 20, 2009 09:16AM

Re: 3dFDR and -list function

Bob Cox February 20, 2009 09:50AM

Re: 3dFDR and -list function

Yuhan February 20, 2009 10:20AM