mirror of https://github.com/lammps/lammps.git
62 lines
1.4 KiB
Python
Executable File
62 lines
1.4 KiB
Python
Executable File
#!/usr/bin/env python -i
|
|
# preceeding line should have path for Python on your machine
|
|
|
|
# demo.py
|
|
# Purpose: illustrate use of many library interface commands
|
|
# Syntax: demo.py
|
|
# uses in.demo as LAMMPS input script
|
|
|
|
import sys
|
|
|
|
# parse command line
|
|
|
|
argv = sys.argv
|
|
if len(argv) != 1:
|
|
print "Syntax: demo.py"
|
|
sys.exit()
|
|
|
|
me = 0
|
|
# uncomment if running in parallel via Pypar
|
|
#import pypar
|
|
#me = pypar.rank()
|
|
#nprocs = pypar.size()
|
|
|
|
from lammps import lammps
|
|
|
|
lmp = lammps()
|
|
|
|
# test out various library functions after running in.demo
|
|
|
|
lmp.file("in.demo")
|
|
|
|
if me == 0: print "\nPython output:"
|
|
|
|
natoms = lmp.extract_global("natoms",0)
|
|
mass = lmp.extract_atom("mass",2)
|
|
x = lmp.extract_atom("x",3)
|
|
print "Natoms, mass, x[0][0] coord =",natoms,mass[1],x[0][0]
|
|
|
|
temp = lmp.extract_compute("thermo_temp",0,0)
|
|
print "Temperature from compute =",temp
|
|
|
|
eng = lmp.extract_variable("eng",None,0)
|
|
print "Energy from equal-style variable =",eng
|
|
|
|
vy = lmp.extract_variable("vy","all",1)
|
|
print "Velocity component from atom-style variable =",vy[1]
|
|
|
|
natoms = lmp.get_natoms()
|
|
print "Natoms from get_natoms =",natoms
|
|
|
|
xc = lmp.gather_atoms("x",1,3)
|
|
print "Global coords from gather_atoms =",xc[0],xc[1],xc[31]
|
|
|
|
xc[0] = xc[0] + 1.0
|
|
lmp.scatter_atoms("x",1,3,xc)
|
|
|
|
print "Changed x[0][0] via scatter_atoms =",x[0][0]
|
|
|
|
# uncomment if running in parallel via Pypar
|
|
#print "Proc %d out of %d procs has" % (me,nprocs), lmp
|
|
#pypar.finalize()
|