Where i did mistake in lammps input code?

LAMMPS LAMMPS Beginners
1

I tried to extract force components but im getting error

compute f1 poly force/tally

variable fx equal c_f1[1]

variable fy equal c_f1[2]

variable fz equal c_f1[3]

fix ff poly ave/correlate 1 100 100 c_f1[1] c_f1[2] c_f1[3] type auto file force.dat ave running

ERROR:

Illegal compute force/tally command: missing argument(s) (src/TALLY/compute_force_tally.cpp:33)

Last command: compute f1 poly force/tally

please help me where I did mistake?

2

You should try to imitate the syntax from the documentation : compute force/tally command — LAMMPS documentation, a group ID is missing.

Simon