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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Peng Ren
September 23, 2020 11:16AM
Dear AFNI experts,

I am trying to calculate spatial correlation between single subject PET and MRI with 3ddot, which i think is the proper command to use, right? the output seems to only contain one single r value, are there any way to get proper p value with such large DOF? I've seen spatial permutation test(spin test) in surface based analysis, but not appliable to my case, are there any similar solutions in AFNI?

Besides, what's behind default 3ddot, since the result from 3ddot is not exactly the same as that calculate directly from afni_matlab

Best wishes,
Peng

[rp@localhost data]$ 3ddot MRI_26+tlrc. PET_26+tlrc
0.953988

MRI=BrikLoad('MRI_26+tlrc');
PET=BrikLoad('PET_26+tlrc');
MRIOneDim = reshape(MRI,1,[]);
PETOneDim = reshape(PET,1,[]);
corrcoef(MRIOneDim, PETOneDim)
ans =
1.000000000000000 0.946982442535485
0.946982442535485 1.000000000000000
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Subject Author Posted

Ask for the significance of 3ddot result

Peng Ren September 23, 2020 11:16AM

Re: Ask for the significance of 3ddot result

Daniel Glen September 24, 2020 11:20AM

Re: Ask for the significance of 3ddot result

Peng Ren September 25, 2020 11:45AM