2010-11-02 23:07:40 +08:00
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#!/usr/local/bin/python -i
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# preceeding line should have path for Python on your machine
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# demo.py
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# Purpose: illustrate use of many library interface commands
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# Syntax: demo.py
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# uses in.demo as LAMMPS input script
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import sys
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# parse command line
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argv = sys.argv
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if len(argv) != 1:
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print "Syntax: demo.py"
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sys.exit()
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me = 0
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# uncomment if running in parallel via Pypar
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#import pypar
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#me = pypar.rank()
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#nprocs = pypar.size()
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from lammps import lammps
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lmp = lammps()
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# test out various library functions after running in.demo
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lmp.file("in.demo")
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if me == 0: print "\nPython output:"
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2012-10-25 23:21:33 +08:00
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natoms = lmp.extract_global("natoms",0)
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mass = lmp.extract_atom("mass",2)
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x = lmp.extract_atom("x",3)
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2010-11-02 23:07:40 +08:00
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print "Natoms, mass, x[0][0] coord =",natoms,mass[1],x[0][0]
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temp = lmp.extract_compute("thermo_temp",0,0)
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print "Temperature from compute =",temp
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eng = lmp.extract_variable("eng",None,0)
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print "Energy from equal-style variable =",eng
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vy = lmp.extract_variable("vy","all",1)
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print "Velocity component from atom-style variable =",vy[1]
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natoms = lmp.get_natoms()
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print "Natoms from get_natoms =",natoms
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2012-10-25 23:21:33 +08:00
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xc = lmp.gather_atoms("x",1,3)
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print "Global coords from gather_atoms =",xc[0],xc[1],xc[31]
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2010-11-02 23:07:40 +08:00
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xc[0] = xc[0] + 1.0
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2012-10-25 23:21:33 +08:00
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lmp.scatter_atoms("x",1,3,xc)
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2010-11-02 23:07:40 +08:00
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2012-10-25 23:21:33 +08:00
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print "Changed x[0][0] via scatter_atoms =",x[0][0]
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2010-11-02 23:07:40 +08:00
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# uncomment if running in parallel via Pypar
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#print "Proc %d out of %d procs has" % (me,nprocs), lmp
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#pypar.finalize()
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