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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February 22, 2008 03:22PM
> Can you please tell me how 3dDeconvolve finds the beta weights
> without caring about the amplitude difference between the
> regressors and the data?

The beta vector (of all regressors) in a regression model Y = Xb + e is basically solved as

b = (X'X)^-1 X'Y

The columns in design matrix X are the regressors. So if you scale one regressor by a factor c, the above formula indicates that the beta for this scald regressor would be c times the original beta value.

Gang
Subject Author Posted

normalized regressors for 3dDeconvolve

cathy February 22, 2008 09:43AM

Re: normalized regressors for 3dDeconvolve

Gang Chen February 22, 2008 03:22PM

Re: normalized regressors for 3dDeconvolve

rick reynolds February 22, 2008 11:29PM

Re: normalized regressors for 3dDeconvolve

cathy February 24, 2008 08:51AM

Re: normalized regressors for 3dDeconvolve

rick reynolds February 24, 2008 09:31AM