AFNI Message Board

Dear AFNI users-

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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  

March 30, 2022 02:55AM

I'm reading the notes of 3dFWHMx, which says
'If you don't want to go to that much trouble, use '-detrend' to approximately subtract out the anatomical spatial structure, OR use the output of 3dDetrend for the same purpose.'

I tried both option on my dataset. First I using 3dDetrend -polort 2 -prefix det dset, and using the output as input for 3dFWHMx. The programs ran successfully. But then I tried using detrend option directly, i.e., 3dFWHMx -detrend 2 -mask aaa -acf bbb -input dset. The program failed the model fitting and showed a list of calfun error.
The output plots are also quite different. I paste their google drivelink as follows, if you are interested, please take a look.

So, my question is the value following -detrend in 3dFWHMx and that following -polort 2 in 3dDetrend a different parameter? If so, what's the difference and is there any explanation for the shape of the plot from 3dFWHMx -detrend 2?

Best regard,
Subject Author Posted

-detrend option in 3dFWHMx vs 3dDetrend

Zixun March 30, 2022 02:55AM

Re: -detrend option in 3dFWHMx vs 3dDetrend

ptaylor April 06, 2022 09:56PM

Re: -detrend option in 3dFWHMx vs 3dDetrend

Zixun May 06, 2022 07:23AM

Re: -detrend option in 3dFWHMx vs 3dDetrend

ptaylor May 10, 2022 10:41AM