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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Lukas Pezawas
February 15, 2003 10:08PM
Hi AFINI experts!

I am a little bit puzzeled why I get negative values at the edges of the skull after using 3dFourier. I do not see negative values in my unfiltered epi.
I am using the following command:

3dFourier -prefix filt \
-highpass .001136364 \
-lowpass .333333333 \
-retrend \
'origepi+orig'

Retrending has been used because the data are filtered before deconvolution and the data will be detrended (linear trend) anyway, if I correctly understood 3dDeconvolve.
However, I am a little bit bothered by these negative values and I am not quite sure, if they would harm anything further on.

Any suggestions would be appreciated,

Lukas
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Negative Values

Lukas Pezawas February 15, 2003 10:08PM

Re: Negative Values

bob cox February 16, 2003 10:48AM

Thanks!

Lukas Pezawas February 16, 2003 03:43PM