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

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bob cox
October 20, 2009 08:47AM
The lowest nonzero frequency in a dataset with N time points is 1/(N*TR) -- in Hz. In your case, the N is 96, the first "legal" FFT length >= 90, so the lowest frequency is 1/(96*2)=0.00520833 Hz. So you can't cutoff frequencies below that in the data since they don't have a full period in the time span of the dataset. Your possible recourses:
(a) omit the -highpass option
(b) increase the cutoff to be above 0.00520833 Hz.

Your post is a reminder that I should finish up the 3dBandpass program, as well. Too much to do ....
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Subject Author Posted

3dFourier error

Colm Connolly October 20, 2009 08:19AM

Re: 3dFourier error

bob cox October 20, 2009 08:47AM