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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bob cox
December 24, 2002 08:57AM
At present, AFNI does not directly support any statistic whose parameters vary from voxel to voxel. This is the main reason why the unpooled variance t test is not advised, since there is no easy way to threshold it coherently. It would be possible to modify 3dttest to save the DOF parameter per voxel, but then it would be necessary to use 3dcalc to convert (t,DOF) pair to some other statistic (e.g., a z score) for coherent thresholding and inference.

bob cox
Subject Author Posted

Unpooled variance ttests

Lisa Eyler Zorrilla December 23, 2002 08:00PM

Re: Unpooled variance ttests

bob cox December 24, 2002 08:57AM

Re: Unpooled variance ttests

Lisa Eyler Zorrilla December 24, 2002 04:39PM

Re: Unpooled variance ttests - Addition to 3ddtest

bob cox December 27, 2002 12:04PM