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".
> 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]
> 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.
Gang