[lammps-users] history of a variable

Dear LAMMPS admins,

I have two questions.
Is it possible to track a variable (say, total force on a particle) for a period of time without dumping it out every step?

Is it possible to make a list of particles sharing some common property (say all have interaction with a wall)?



1 - what does it mean to "track" something if you're
not printing it out? If you just want to print it out
less often, then fix print will do that.

2 - LAMMPS has "groups" of atoms which are defined
in various ways. They are not dynamic. What do you
want to do with the "list" you create?