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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April 29, 2005 11:14PM
Hello AFNI experts,
I'm putting together some time series plots overlaying model fits over data, and I was wondering if there was an option in the new 3dDeconvolve (or some other easy way) to selectively regress out the -polort legendre polynomial terms. Using matlab-style notation, here's what I want to do:

y is original data
X is design matrix, X = [P,M] where P are the legendre polynomial column vectors, and M are the model vectors.
b is the parameter vector b = [b_p; b_m], corresponding to the P and M terms above, with their least-squares estimates denoted b_hat, b_p_hat, and b_m_hat, respectively

I would like the generate the following 3d+time data:

y_detrend = y - P*b_p_hat;
fit_detrend = M*b_m_hat;

Can you think of a simple way to do this? The main reason for wanting to do this is to have an alternative visualization of how my fMRI signal model M is fitting the data without getting confused by the signal drifts. Thanks for any advice you might have!
--Patrick
Subject Author Posted

Regressing out -polort terms

Patrick Purdon April 29, 2005 11:14PM

Re: Regressing out -polort terms

Bob Cox April 30, 2005 04:01PM