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
November 20, 2003 01:11PM
If you want
exp(-r*r/(f*b*b))
to have Full Width at Half Maximum (FWHM) to be b, then you want
exp(-(b/2)*(b/2)/(f*b*b))=1/2
(i.e., the Half width at half max is b/2, so exp(-r*r/(f*b*b))=1/2 at r=b/2). That is, you want
exp(-1/(4*f))=2
or
1/(4*f)=log(2)
or
f=1/(4*log(2))=0.360674.
Here, I use log() as the natural logarithm, as is common among mathematicians (who have no use for log-base-10).

zorkon the magnificent

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Subject Author Posted

3dmerge Gaussian

George Tourtellot November 20, 2003 10:24AM

Re: 3dmerge Gaussian

bob cox November 20, 2003 01:11PM

Re: 3dmerge Gaussian

Gang Chen November 20, 2003 01:20PM