Is this what you are looking for?
https://surfer.nmr.mgh.harvard.edu/pub/docs/wiki/mris_calc.help.xml.html
From: freesurfer-bounces@nmr.mgh.harvard.edu <freesurfer-bounces@nmr.mgh.harvard.edu>
On Behalf Of Aaron Tanenbaum
Sent: Tuesday, July 9, 2024 2:07 PM
To: Freesurfer <Freesurfer@nmr.mgh.harvard.edu>
Subject: [Freesurfer] Doing math on mgz file
External Email - Use Caution
Is there an equivalent to fslmaths in freesurfer?
Thank you