#!/usr/bin/env python -i
# preceeding line should have path for Python on your machine

# simple.py
# Purpose: mimic operation of couple/simple/simple.cpp via Python
# Syntax:  simple.py in.lammps
#          in.lammps = LAMMPS input script

import sys

infile = 'in.simple'
me = 0

from lammps import lammps
lmp = lammps(cmdargs=sys.argv[1:])

# run infile one line at a time

lines = open(infile,'r').readlines()
for line in lines: lmp.command(line)

lmp.command("run 10")
x = lmp.gather_atoms("x",1,3)
epsilon = 0.1
x[0] += epsilon
lmp.scatter_atoms("x",1,3,x)
lmp.command("run 1");

f = lmp.extract_atom("f",3)
print "Force on 1 atom via extract_atom: ",f[0][0]

fx = lmp.extract_variable("fx","all",1)
print "Force on 1 atom via extract_variable:",fx[0]