Adding motion parameter files together

AFNI version info (afni -ver): Version AFNI_23.0.07 'Commodus'


If I run two 3dvolreg algorithms back to back, and get two dfiles of the motion parameters; is it safe to say I can just add the respective values in these files to get the total motion parameter of the two? I hope that makes sense. Thanks in advance!


Hi Edwin,

Yes, dfiles for multiple runs can be concatenated. However, we apply them as per-run regressors, so they are broken apart for that.
See how does it:, tracking dfile_rall.1D and then mot_demean within the script.

  • rick