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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Xiangchuan Chen
February 06, 2003 12:25PM
Hi all,

I found a problem with 3dcalc when doing normalization on a 3D+time data set. The process is as follows (Suppose the 3D+time data set is func+orig):
1. Calculate the mean data set (mean+orig) using 3D Statistic plug-in
2. 3dcalc [-gscale / -fscale / -nscale] –prefix func_norm –a func+orig –b mean+orig -expr “a/b*100” (or “a*100/b”, or “a/b”)

The problem is that some parts of the time course curves look like dashes – in each of these dashes the normalized intensity values of several continuous time points are all the same. I have tried -gscale, -fscale, -nscale, or without scale option and got the same result. Does anybody know how to deal with this problem?

Thanks in advance
Xiangchuan Chen
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Subject Author Posted

problem with 3dcalc

Xiangchuan Chen February 06, 2003 12:25PM

Re: problem with 3dcalc

bob cox February 06, 2003 02:07PM