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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Gang Chen
February 08, 2006 05:16PM
> I would like to be able to determine whether a given variable
> (such as age) is best fit to the task response with a linear or a
> non-linear model. How might I go about doing this? It has been
> suggested that I enter both the independent variable and the
> squared independent variable into 3dRegAna (in 2 separate
> columns). Is this the appropriate way to examine this question?

Check out examples 2 and 3 on pages 17-22 in 3dRegAna manual:

http://afni.nimh.nih.gov/pub/dist/doc/manual/3dRegAnam.pdf

> how might I determine whether the linear or non-linear model
> best fits the data?

Add option -fcoef in 3dRegAna for each coefficient of the model, and the F value is the proportion of variation in the data that can be explained by that regressor.

Gang
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Subject Author Posted

Non-linear regression

Bonnie Nagel February 08, 2006 03:21PM

Re: Non-linear regression

Gang Chen February 08, 2006 05:16PM

Re: Non-linear regression

Bonnie Nagel February 08, 2006 05:52PM