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
|
Linda Heidinger
June 16, 2009 03:11PM
Hi Dr. Cox,
Thank you very much for your elaborate reply. I have been trying to orthogonalize the behavioral response regressors from our experiment to the SCM in hopes of getting from these regressors unique beta coefficients which represent unique variance as compared to the mean or IRF. I have been getting IRFs that change significantly as compared to those IRFs without the added regressors especially when the TS had great variability (unsmoothed). I felt it was the precision because of this but when I look at how orthogonal the vectors are from the SCM, I find they are no better than 10-6 when doing the dot product. Again I suppose they round to float, although MATLAB I think uses double precision also in its internal calculations. I was confused that maybe something was done in single precision.
thanks,
Linda Heidinger
Reply Quote
RSS
Subject Author Posted

double precision

Linda Heidinger June 16, 2009 01:47PM

Re: double precision

bob cox June 16, 2009 02:47PM

Re: double precision

Linda Heidinger June 16, 2009 03:11PM