File: lammps.py

package info (click to toggle)
liggghts 3.0.3%2Brepack-2
  • links: PTS, VCS
  • area: main
  • in suites: jessie, jessie-kfreebsd
  • size: 106,076 kB
  • ctags: 34,406
  • sloc: cpp: 363,723; python: 21,138; ansic: 9,146; perl: 3,687; sh: 2,841; fortran: 2,802; xml: 788; makefile: 485; objc: 238; lisp: 169; f90: 145; csh: 16; awk: 14
file content (167 lines) | stat: -rwxr-xr-x 6,013 bytes parent folder | download | duplicates (3)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
# ----------------------------------------------------------------------
#   LAMMPS - Large-scale Atomic/Molecular Massively Parallel Simulator
#   http://lammps.sandia.gov, Sandia National Laboratories
#   Steve Plimpton, sjplimp@sandia.gov
#
#   Copyright (2003) Sandia Corporation.  Under the terms of Contract
#   DE-AC04-94AL85000 with Sandia Corporation, the U.S. Government retains
#   certain rights in this software.  This software is distributed under 
#   the GNU General Public License.
#
#   See the README file in the top-level LAMMPS directory.
# -------------------------------------------------------------------------

# Python wrapper on LAMMPS library via ctypes

import sys,traceback,types
from ctypes import *

class lammps:
  def __init__(self,name="",cmdargs=None):

    # load liblammps.so by default
    # if name = "g++", load liblammps_g++.so
    
    try:
      if not name: self.lib = CDLL("liblammps.so",RTLD_GLOBAL)
      else: self.lib = CDLL("liblammps_%s.so" % name,RTLD_GLOBAL)
    except:
      type,value,tb = sys.exc_info()
      traceback.print_exception(type,value,tb)
      raise OSError,"Could not load LAMMPS dynamic library"

    # create an instance of LAMMPS
    # don't know how to pass an MPI communicator from PyPar
    # no_mpi call lets LAMMPS use MPI_COMM_WORLD
    # cargs = array of C strings from args
    
    if cmdargs:
      cmdargs.insert(0,"lammps.py")
      narg = len(cmdargs)
      cargs = (c_char_p*narg)(*cmdargs)
      self.lmp = c_void_p()
      self.lib.lammps_open_no_mpi(narg,cargs,byref(self.lmp))
    else:
      self.lmp = c_void_p()
      self.lib.lammps_open_no_mpi(0,None,byref(self.lmp))
      # could use just this if LAMMPS lib interface supported it
      # self.lmp = self.lib.lammps_open_no_mpi(0,None)

  def __del__(self):
    if self.lmp: self.lib.lammps_close(self.lmp)

  def close(self):
    self.lib.lammps_close(self.lmp)
    self.lmp = None

  def file(self,file):
    self.lib.lammps_file(self.lmp,file)

  def command(self,cmd):
    self.lib.lammps_command(self.lmp,cmd)

  def extract_global(self,name,type):
    if type == 0:
      self.lib.lammps_extract_global.restype = POINTER(c_int)
    elif type == 1:
      self.lib.lammps_extract_global.restype = POINTER(c_double)
    else: return None
    ptr = self.lib.lammps_extract_global(self.lmp,name)
    return ptr[0]

  def extract_atom(self,name,type):
    if type == 0:
      self.lib.lammps_extract_atom.restype = POINTER(c_int)
    elif type == 1:
      self.lib.lammps_extract_atom.restype = POINTER(POINTER(c_int))
    elif type == 2:
      self.lib.lammps_extract_atom.restype = POINTER(c_double)
    elif type == 3:
      self.lib.lammps_extract_atom.restype = POINTER(POINTER(c_double))
    else: return None
    ptr = self.lib.lammps_extract_atom(self.lmp,name)
    return ptr

  def extract_compute(self,id,style,type):
    if type == 0:
      if style > 0: return None
      self.lib.lammps_extract_compute.restype = POINTER(c_double)
      ptr = self.lib.lammps_extract_compute(self.lmp,id,style,type)
      return ptr[0]
    if type == 1:
      self.lib.lammps_extract_compute.restype = POINTER(c_double)
      ptr = self.lib.lammps_extract_compute(self.lmp,id,style,type)
      return ptr
    if type == 2:
      self.lib.lammps_extract_compute.restype = POINTER(POINTER(c_double))
      ptr = self.lib.lammps_extract_compute(self.lmp,id,style,type)
      return ptr
    return None

  # in case of global datum, free memory for 1 double via lammps_free()
  # double was allocated by library interface function
  
  def extract_fix(self,id,style,type,i=0,j=0):
    if type == 0:
      if style > 0: return None
      self.lib.lammps_extract_fix.restype = POINTER(c_double)
      ptr = self.lib.lammps_extract_fix(self.lmp,id,style,type,i,j)
      result = ptr[0]
      self.lib.lammps_free(ptr)
      return result
    if type == 1:
      self.lib.lammps_extract_fix.restype = POINTER(c_double)
      ptr = self.lib.lammps_extract_fix(self.lmp,id,style,type,i,j)
      return ptr
    if type == 2:
      self.lib.lammps_extract_fix.restype = POINTER(POINTER(c_double))
      ptr = self.lib.lammps_extract_fix(self.lmp,id,style,type,i,j)
      return ptr
    return None

  # free memory for 1 double or 1 vector of doubles via lammps_free()
  # for vector, must copy nlocal returned values to local c_double vector
  # memory was allocated by library interface function
  
  def extract_variable(self,name,group,type):
    if type == 0:
      self.lib.lammps_extract_variable.restype = POINTER(c_double)
      ptr = self.lib.lammps_extract_variable(self.lmp,name,group)
      result = ptr[0]
      self.lib.lammps_free(ptr)
      return result
    if type == 1:
      self.lib.lammps_extract_global.restype = POINTER(c_int)
      nlocalptr = self.lib.lammps_extract_global(self.lmp,"nlocal")
      nlocal = nlocalptr[0]
      result = (c_double*nlocal)()
      self.lib.lammps_extract_variable.restype = POINTER(c_double)
      ptr = self.lib.lammps_extract_variable(self.lmp,name,group)
      for i in xrange(nlocal): result[i] = ptr[i]
      self.lib.lammps_free(ptr)
      return result
    return None

  # return total number of atoms in system
  
  def get_natoms(self):
    return self.lib.lammps_get_natoms(self.lmp)

  # return vector of atom properties gathered across procs, ordered by atom ID

  def gather_atoms(self,name,type,count):
    natoms = self.lib.lammps_get_natoms(self.lmp)
    if type == 0:
      data = ((count*natoms)*c_int)()
      self.lib.lammps_gather_atoms(self.lmp,name,type,count,data)
    elif type == 1:
      data = ((count*natoms)*c_double)()
      self.lib.lammps_gather_atoms(self.lmp,name,type,count,data)
    else: return None
    return data

  # scatter vector of atom properties across procs, ordered by atom ID
  # assume vector is of correct type and length, as created by gather_atoms()

  def scatter_atoms(self,name,type,count,data):
    self.lib.lammps_scatter_atoms(self.lmp,name,type,count,data)