[lammps-users] How to calculate the pressure of part of simulation box

Hey All,
Had anyone tried to calculate the pressure (px, py, pz) of part of the simulation box ?
It seems compute can only calculate the total pressure.

This is what I have done:

compute peratom water stress/atom
compute p water reduce sum c_peratom[1] c_peratom[2] c_peratom[3]
variable waterP equal -(c_p[1]+c_p[2]+c_p[3])/(3*vol)
thermo_style custom v_waterP


Compute stress/atom will compute the local stress (pressure)
on individual atoms, so include whichever atoms you want.