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  

Previous Message Next Message
Message List New Topic Print View
|
Judd
September 26, 2007 12:20PM
I'm new to 3dDeconvolve so apologies in advance.

It seems that when you use -nfirst>0 with -legendre then the integrals of the 1st and higher order polynomial columns of the xmatrix are not zero. This was somewhat unexpected. As a result, estimating the voxel average response is cumbersome (i.e. I think I need to integrate the columns of the xmatrix and use all fit coefficients?) On the otherhand when nfirst=0 the columns integrate close to zero.

So it seem there are two options:

(1) Chop the data before 3dDeconvolve and use -nfirst 0

(2) Customize the xmatrix and reconvolve by removing the mean from the columns

Advice? Thank you

--judd
Reply Quote
RSS
Subject Author Posted

Question about Legendre polynomials and -nfirst

Judd September 26, 2007 12:20PM

Re: Question about Legendre polynomials and -nfirst

Judd September 26, 2007 12:44PM