I created a cylindrical region inside a simulation box (100x100x100) with initial position at x = 50, y = 50 and initial radius = 5 and length = 100 units box. I am able to obtain the updated length of the cylinder via the simulation length lz. How can I obtain the updated cylinder radius during the simulation, without using the atomic positions.
variable r equal 5
region sim block 0 100 0 100 0 100 units box
create_box 1 sim
region cyl cylinder z 50 50 $r INF INF units box
create_atoms 1 region cyl