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

History of AFNI updates  

|
August 01, 2014 07:47PM
Gang Wrote:
-------------------------------------------------------
> Hi Michael,
>
>
> > If we take the square root of cov1_r+tlrc, is
> the partial correlation coefficient for covariate
> 1
> > while controlling for covariate 2?
>
> Do the two files give you the same or different
> results? This is what it says in Doug Ward's
> manual for 3dRegAna: "R^2 is an indicator of the
> efficacy of the overall regression, and does not
> indicate the significance of the individual
> parameter".

Yes, the two files are equal. So, R^2 is for the overall regression model and not partial. The value is equal if I use the -brick m rstat option, which is the coefficient of multiple determination R^2

>
> > if so, if we also generated the -tcoef k file,
> will the sign of the -tcoef coefficient/t
> determine
> > the sign of the partial correlation coefficient?
>
>
> According to the manual, the R^2 is not really the
> partial determination coefficient. However, you
> can directly obtain the partial correlation
> coefficient based on the t-value using the
> conversion formula on the following page:
>
> [afni.nimh.nih.gov]
>

Thanks! This is exactly what we want.


> > Is there an easier way to generate these files
> into one file? 3dRegAna outputs these files
> separately.
>
> You can use option -bucket to bundle everything
> into one file.
>
> > Is it possible to generate the same results
> using 3dttest++ or another program?
>
> Yes, you can use 3dttest++ to get everything
> except for R^2.

Thanks again.
Subject Author Posted

3dRegAna -rcoef option

mrif July 31, 2014 05:36PM

Re: 3dRegAna -rcoef option

gang August 01, 2014 12:12PM

Re: 3dRegAna -rcoef option

mrif August 01, 2014 07:47PM