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  

|
February 04, 2020 09:42PM
Hi, Sam-

Re. DF (degree of freedom) counting: yes, you are correct. Adding a regressor to a general linear model means using up one degree of freedom. Censoring can be done (as you note) by including a column of all zeros except for a 1 at the time point to be censored-- hence, censoring using 1 DF. Interestingly to bandpass a given frequency, you have to include *both* a sin() and cos() form of it in the model, so that uses up 2 DFs. That is part of the reason why bandpassing is so expensive, in terms of DFs. And indeed, bandpassing won't zero-out a time point (but you might see some apparent 'ringing' effects).

(To your point on a paper-- there is one in progress. It has taken a while to progress, because of so many topics involved, but slowly, slowly...)

--pt
Subject Author Posted

is band pass filter recommended?

samw September 18, 2019 06:43PM

Re: is band pass filter recommended?

ptaylor September 23, 2019 09:48AM

Re: is band pass filter recommended?

samw February 03, 2020 02:04PM

Re: is band pass filter recommended?

ptaylor February 04, 2020 10:11AM

Re: is band pass filter recommended?

samw February 04, 2020 05:23PM

Re: is band pass filter recommended?

ptaylor February 04, 2020 09:42PM

Re: is band pass filter recommended?

kausar May 28, 2020 11:03AM