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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herrlich10
May 08, 2017 09:49PM
Hi everyone,

I'm sorry but I'm getting a little confused about cat_matvec.
I defined two 3x3 matrices A and B, and did
cat_matvec A B > C
and fould C=B*A, which suggests transform A is applied first, and then B is applied.
This is exactly what the doc describes.

So if I'd like to volreg a dset, then align it to anat, I should do
cat_matvec volreg align > combined
3dAllineate -1Dmatrix_apply combined
Is it correct?

But I found the script generated by afni_proc.py seemed to do the opposite:
cat_matvec align volreg > combined

How to understand the order of operation during xform concatenation?

Thanks very much!



Edited 1 time(s). Last edit at 05/08/2017 09:50PM by herrlich10.
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Subject Author Posted

Order of operation when catenate transforms with cat_matvec

herrlich10 May 08, 2017 09:49PM

Re: Order of operation when catenate transforms with cat_matvec

ptaylor May 08, 2017 11:27PM

Re: Order of operation when catenate transforms with cat_matvec

herrlich10 May 09, 2017 12:35AM

Re: Order of operation when catenate transforms with cat_matvec

ptaylor May 09, 2017 08:33AM

Re: Order of operation when catenate transforms with cat_matvec

herrlich10 May 09, 2017 09:58AM