542 lines
20 KiB
Python
542 lines
20 KiB
Python
# ----------------------------------------------------------------------
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# LAMMPS - Large-scale Atomic/Molecular Massively Parallel Simulator
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# https://www.lammps.org/ Sandia National Laboratories
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# LAMMPS Development team: developers@lammps.org
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#
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# Copyright (2003) Sandia Corporation. Under the terms of Contract
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# DE-AC04-94AL85000 with Sandia Corporation, the U.S. Government retains
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# certain rights in this software. This software is distributed under
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# the GNU General Public License.
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#
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# See the README file in the top-level LAMMPS directory.
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# -------------------------------------------------------------------------
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################################################################################
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# NumPy additions
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# Written by Richard Berger <richard.berger@temple.edu>
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################################################################################
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import warnings
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from ctypes import POINTER, c_void_p, c_char_p, c_double, c_int, c_int32, c_int64, cast
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from .constants import * # lgtm [py/polluting-import]
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from .data import NeighList
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class numpy_wrapper:
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"""lammps API NumPy Wrapper
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This is a wrapper class that provides additional methods on top of an
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existing :py:class:`lammps` instance. The methods transform raw ctypes
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pointers into NumPy arrays, which give direct access to the
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original data while protecting against out-of-bounds accesses.
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There is no need to explicitly instantiate this class. Each instance
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of :py:class:`lammps` has a :py:attr:`numpy <lammps.numpy>` property
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that returns an instance.
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:param lmp: instance of the :py:class:`lammps` class
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:type lmp: lammps
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"""
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def __init__(self, lmp):
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self.lmp = lmp
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# -------------------------------------------------------------------------
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def _ctype_to_numpy_int(self, ctype_int):
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import numpy as np
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if ctype_int == c_int32:
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return np.int32
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elif ctype_int == c_int64:
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return np.int64
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return np.intc
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# -------------------------------------------------------------------------
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def extract_atom(self, name, dtype=LAMMPS_AUTODETECT, nelem=LAMMPS_AUTODETECT, dim=LAMMPS_AUTODETECT):
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"""Retrieve per-atom properties from LAMMPS as NumPy arrays
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This is a wrapper around the :py:meth:`lammps.extract_atom()` method.
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It behaves the same as the original method, but returns NumPy arrays
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instead of ``ctypes`` pointers.
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.. note::
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The returned arrays of per-atom data are by default dimensioned
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for the range [0:nlocal] since that data is *always* valid. The
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underlying storage for the data, however, is typically allocated
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for the range of [0:nmax]. Whether there is valid data in the range
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[nlocal:nlocal+nghost] depends on whether the property of interest
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is also updated for ghost atoms. This is not often the case. In
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some cases, it depends on a LAMMPS setting, see for example
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:doc:`comm_modify vel yes <comm_modify>`. By using the optional
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*nelem* parameter the size of the returned NumPy can be overridden.
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There is no check whether the number of elements chosen is valid.
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:param name: name of the property
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:type name: string
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:param dtype: type of the returned data (see :ref:`py_datatype_constants`)
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:type dtype: int, optional
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:param nelem: number of elements in array
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:type nelem: int, optional
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:param dim: dimension of each element
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:type dim: int, optional
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:return: requested data as NumPy array with direct access to C data or None
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:rtype: numpy.array or NoneType
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"""
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if dtype == LAMMPS_AUTODETECT:
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dtype = self.lmp.extract_atom_datatype(name)
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if nelem == LAMMPS_AUTODETECT:
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if name == "mass":
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nelem = self.lmp.extract_global("ntypes") + 1
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else:
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nelem = self.lmp.extract_global("nlocal")
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if dim == LAMMPS_AUTODETECT:
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if dtype in (LAMMPS_INT_2D, LAMMPS_DOUBLE_2D, LAMMPS_INT64_2D):
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# TODO add other fields
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if name in ("x", "v", "f", "x0","omega", "angmom", "torque", "csforce", "vforce", "vest"):
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dim = 3
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elif name == "smd_data_9":
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dim = 9
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elif name == "smd_stress":
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dim = 6
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else:
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dim = 2
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else:
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dim = 1
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raw_ptr = self.lmp.extract_atom(name, dtype)
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if dtype in (LAMMPS_DOUBLE, LAMMPS_DOUBLE_2D):
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return self.darray(raw_ptr, nelem, dim)
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elif dtype in (LAMMPS_INT, LAMMPS_INT_2D):
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return self.iarray(c_int32, raw_ptr, nelem, dim)
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elif dtype in (LAMMPS_INT64, LAMMPS_INT64_2D):
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return self.iarray(c_int64, raw_ptr, nelem, dim)
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return raw_ptr
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# -------------------------------------------------------------------------
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def extract_atom_iarray(self, name, nelem, dim=1):
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warnings.warn("deprecated, use extract_atom instead", DeprecationWarning)
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if name in ['id', 'molecule']:
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c_int_type = self.lmp.c_tagint
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elif name in ['image']:
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c_int_type = self.lmp.c_imageint
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else:
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c_int_type = c_int
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if dim == 1:
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raw_ptr = self.lmp.extract_atom(name, LAMMPS_INT)
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else:
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raw_ptr = self.lmp.extract_atom(name, LAMMPS_INT_2D)
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return self.iarray(c_int_type, raw_ptr, nelem, dim)
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# -------------------------------------------------------------------------
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def extract_atom_darray(self, name, nelem, dim=1):
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warnings.warn("deprecated, use extract_atom instead", DeprecationWarning)
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if dim == 1:
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raw_ptr = self.lmp.extract_atom(name, LAMMPS_DOUBLE)
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else:
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raw_ptr = self.lmp.extract_atom(name, LAMMPS_DOUBLE_2D)
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return self.darray(raw_ptr, nelem, dim)
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# -------------------------------------------------------------------------
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def extract_compute(self, cid, cstyle, ctype):
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"""Retrieve data from a LAMMPS compute
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This is a wrapper around the
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:py:meth:`lammps.extract_compute() <lammps.lammps.extract_compute()>` method.
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It behaves the same as the original method, but returns NumPy arrays
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instead of ``ctypes`` pointers.
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:param cid: compute ID
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:type cid: string
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:param cstyle: style of the data retrieve (global, atom, or local), see :ref:`py_style_constants`
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:type cstyle: int
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:param ctype: type of the returned data (scalar, vector, or array), see :ref:`py_type_constants`
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:type ctype: int
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:return: requested data either as float, as NumPy array with direct access to C data, or None
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:rtype: float, numpy.array, or NoneType
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"""
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value = self.lmp.extract_compute(cid, cstyle, ctype)
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if cstyle == LMP_STYLE_GLOBAL:
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if ctype == LMP_TYPE_VECTOR:
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nrows = self.lmp.extract_compute(cid, cstyle, LMP_SIZE_VECTOR)
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return self.darray(value, nrows)
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elif ctype == LMP_TYPE_ARRAY:
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nrows = self.lmp.extract_compute(cid, cstyle, LMP_SIZE_ROWS)
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ncols = self.lmp.extract_compute(cid, cstyle, LMP_SIZE_COLS)
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return self.darray(value, nrows, ncols)
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elif cstyle == LMP_STYLE_LOCAL:
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nrows = self.lmp.extract_compute(cid, cstyle, LMP_SIZE_ROWS)
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ncols = self.lmp.extract_compute(cid, cstyle, LMP_SIZE_COLS)
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if ncols == 0:
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return self.darray(value, nrows)
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else:
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return self.darray(value, nrows, ncols)
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elif cstyle == LMP_STYLE_ATOM:
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if ctype == LMP_TYPE_VECTOR:
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nlocal = self.lmp.extract_global("nlocal")
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return self.darray(value, nlocal)
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elif ctype == LMP_TYPE_ARRAY:
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nlocal = self.lmp.extract_global("nlocal")
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ncols = self.lmp.extract_compute(cid, cstyle, LMP_SIZE_COLS)
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return self.darray(value, nlocal, ncols)
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return value
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# -------------------------------------------------------------------------
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def extract_fix(self, fid, fstyle, ftype, nrow=0, ncol=0):
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"""Retrieve data from a LAMMPS fix
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This is a wrapper around the :py:meth:`lammps.extract_fix() <lammps.lammps.extract_fix()>` method.
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It behaves the same as the original method, but returns NumPy arrays
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instead of ``ctypes`` pointers.
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:param fid: fix ID
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:type fid: string
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:param fstyle: style of the data retrieve (global, atom, or local), see :ref:`py_style_constants`
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:type fstyle: int
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:param ftype: type or size of the returned data (scalar, vector, or array), see :ref:`py_type_constants`
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:type ftype: int
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:param nrow: index of global vector element or row index of global array element
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:type nrow: int
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:param ncol: column index of global array element
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:type ncol: int
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:return: requested data
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:rtype: integer or double value, pointer to 1d or 2d double array or None
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"""
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value = self.lmp.extract_fix(fid, fstyle, ftype, nrow, ncol)
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if fstyle == LMP_STYLE_ATOM:
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if ftype == LMP_TYPE_VECTOR:
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nlocal = self.lmp.extract_global("nlocal")
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return self.darray(value, nlocal)
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elif ftype == LMP_TYPE_ARRAY:
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nlocal = self.lmp.extract_global("nlocal")
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ncols = self.lmp.extract_fix(fid, fstyle, LMP_SIZE_COLS, 0, 0)
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return self.darray(value, nlocal, ncols)
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elif fstyle == LMP_STYLE_LOCAL:
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if ftype == LMP_TYPE_VECTOR:
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nrows = self.lmp.extract_fix(fid, fstyle, LMP_SIZE_ROWS, 0, 0)
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return self.darray(value, nrows)
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elif ftype == LMP_TYPE_ARRAY:
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nrows = self.lmp.extract_fix(fid, fstyle, LMP_SIZE_ROWS, 0, 0)
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ncols = self.lmp.extract_fix(fid, fstyle, LMP_SIZE_COLS, 0, 0)
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return self.darray(value, nrows, ncols)
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return value
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# -------------------------------------------------------------------------
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def extract_variable(self, name, group=None, vartype=LMP_VAR_EQUAL):
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""" Evaluate a LAMMPS variable and return its data
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This function is a wrapper around the function
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:py:meth:`lammps.extract_variable() <lammps.lammps.extract_variable()>`
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method. It behaves the same as the original method, but returns NumPy arrays
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instead of ``ctypes`` pointers.
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:param name: name of the variable to execute
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:type name: string
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:param group: name of group for atom-style variable (ignored for equal-style variables)
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:type group: string
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:param vartype: type of variable, see :ref:`py_vartype_constants`
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:type vartype: int
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:return: the requested data or None
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:rtype: c_double, numpy.array, or NoneType
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"""
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import numpy as np
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value = self.lmp.extract_variable(name, group, vartype)
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if vartype == LMP_VAR_ATOM:
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return np.ctypeslib.as_array(value)
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return value
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# -------------------------------------------------------------------------
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def gather_bonds(self):
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"""Retrieve global list of bonds as NumPy array
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.. versionadded:: 28Jul2021
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This is a wrapper around :py:meth:`lammps.gather_bonds() <lammps.lammps.gather_bonds()>`
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It behaves the same as the original method, but returns a NumPy array instead
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of a ``ctypes`` list.
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:return: the requested data as a 2d-integer numpy array
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:rtype: numpy.array(nbonds,3)
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"""
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import numpy as np
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nbonds, value = self.lmp.gather_bonds()
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return np.ctypeslib.as_array(value).reshape(nbonds,3)
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# -------------------------------------------------------------------------
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def gather_angles(self):
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""" Retrieve global list of angles as NumPy array
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.. versionadded:: 8Feb2023
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This is a wrapper around :py:meth:`lammps.gather_angles() <lammps.lammps.gather_angles()>`
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It behaves the same as the original method, but returns a NumPy array instead
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of a ``ctypes`` list.
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:return: the requested data as a 2d-integer numpy array
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:rtype: numpy.array(nangles,4)
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"""
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import numpy as np
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nangles, value = self.lmp.gather_angles()
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return np.ctypeslib.as_array(value).reshape(nangles,4)
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# -------------------------------------------------------------------------
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def gather_dihedrals(self):
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""" Retrieve global list of dihedrals as NumPy array
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.. versionadded:: 8Feb2023
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This is a wrapper around :py:meth:`lammps.gather_dihedrals() <lammps.lammps.gather_dihedrals()>`
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It behaves the same as the original method, but returns a NumPy array instead
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of a ``ctypes`` list.
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:return: the requested data as a 2d-integer numpy array
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:rtype: numpy.array(ndihedrals,5)
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"""
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import numpy as np
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ndihedrals, value = self.lmp.gather_dihedrals()
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return np.ctypeslib.as_array(value).reshape(ndihedrals,5)
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# -------------------------------------------------------------------------
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def gather_impropers(self):
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""" Retrieve global list of impropers as NumPy array
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.. versionadded:: 8Feb2023
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This is a wrapper around :py:meth:`lammps.gather_impropers() <lammps.lammps.gather_impropers()>`
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It behaves the same as the original method, but returns a NumPy array instead
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of a ``ctypes`` list.
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:return: the requested data as a 2d-integer numpy array
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:rtype: numpy.array(nimpropers,5)
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"""
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import numpy as np
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nimpropers, value = self.lmp.gather_impropers()
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return np.ctypeslib.as_array(value).reshape(nimpropers,5)
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# -------------------------------------------------------------------------
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def fix_external_get_force(self, fix_id):
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"""Get access to the array with per-atom forces of a fix external instance with a given fix ID.
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.. versionchanged:: 28Jul2021
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This function is a wrapper around the
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:py:meth:`lammps.fix_external_get_force() <lammps.lammps.fix_external_get_force()>`
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method. It behaves the same as the original method, but returns a NumPy array instead
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of a ``ctypes`` pointer.
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:param fix_id: Fix-ID of a fix external instance
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:type: string
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:return: requested data
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:rtype: numpy.array
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"""
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import numpy as np
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nlocal = self.lmp.extract_setting('nlocal')
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value = self.lmp.fix_external_get_force(fix_id)
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return self.darray(value,nlocal,3)
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# -------------------------------------------------------------------------
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def fix_external_set_energy_peratom(self, fix_id, eatom):
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"""Set the per-atom energy contribution for a fix external instance with the given ID.
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.. versionadded:: 28Jul2021
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This function is an alternative to
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:py:meth:`lammps.fix_external_set_energy_peratom() <lammps.lammps.fix_external_set_energy_peratom()>`
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method. It behaves the same as the original method, but accepts a NumPy array
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instead of a list as argument.
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:param fix_id: Fix-ID of a fix external instance
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:type: string
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:param eatom: per-atom potential energy
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:type: numpy.array
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"""
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import numpy as np
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nlocal = self.lmp.extract_setting('nlocal')
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if len(eatom) < nlocal:
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raise Exception('per-atom energy dimension must be at least nlocal')
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c_double_p = POINTER(c_double)
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value = eatom.astype(np.double)
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return self.lmp.lib.lammps_fix_external_set_energy_peratom(self.lmp.lmp, fix_id.encode(),
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value.ctypes.data_as(c_double_p))
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# -------------------------------------------------------------------------
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def fix_external_set_virial_peratom(self, fix_id, vatom):
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"""Set the per-atom virial contribution for a fix external instance with the given ID.
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.. versionadded:: 28Jul2021
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This function is an alternative to
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:py:meth:`lammps.fix_external_set_virial_peratom() <lammps.lammps.fix_external_set_virial_peratom()>`
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method. It behaves the same as the original method, but accepts a NumPy array
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instead of a list as argument.
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:param fix_id: Fix-ID of a fix external instance
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:type: string
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:param eatom: per-atom potential energy
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:type: numpy.array
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"""
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import numpy as np
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nlocal = self.lmp.extract_setting('nlocal')
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if len(vatom) < nlocal:
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raise Exception('per-atom virial first dimension must be at least nlocal')
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if len(vatom[0]) != 6:
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raise Exception('per-atom virial second dimension must be 6')
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c_double_pp = np.ctypeslib.ndpointer(dtype=np.uintp, ndim=1, flags='C')
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# recast numpy array to be compatible with library interface
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value = (vatom.__array_interface__['data'][0]
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+ np.arange(vatom.shape[0])*vatom.strides[0]).astype(np.uintp)
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# change prototype to our custom type
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self.lmp.lib.lammps_fix_external_set_virial_peratom.argtypes = [ c_void_p, c_char_p, c_double_pp ]
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self.lmp.lib.lammps_fix_external_set_virial_peratom(self.lmp.lmp, fix_id.encode(), value)
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# -------------------------------------------------------------------------
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def get_neighlist(self, idx):
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"""Returns an instance of :class:`NumPyNeighList` which wraps access to the neighbor list with the given index
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:param idx: index of neighbor list
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:type idx: int
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:return: an instance of :class:`NumPyNeighList` wrapping access to neighbor list data
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:rtype: NumPyNeighList
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"""
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if idx < 0:
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return None
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return NumPyNeighList(self.lmp, idx)
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# -------------------------------------------------------------------------
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def get_neighlist_element_neighbors(self, idx, element):
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"""Return data of neighbor list entry
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This function is a wrapper around the function
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:py:meth:`lammps.get_neighlist_element_neighbors() <lammps.lammps.get_neighlist_element_neighbors()>`
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method. It behaves the same as the original method, but returns a NumPy array containing the neighbors
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instead of a ``ctypes`` pointer.
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:param element: neighbor list index
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:type element: int
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:param element: neighbor list element index
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:type element: int
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:return: tuple with atom local index and numpy array of neighbor local atom indices
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:rtype: (int, numpy.array)
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"""
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iatom, numneigh, c_neighbors = self.lmp.get_neighlist_element_neighbors(idx, element)
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neighbors = self.iarray(c_int, c_neighbors, numneigh, 1)
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return iatom, neighbors
|
|
|
|
# -------------------------------------------------------------------------
|
|
|
|
def iarray(self, c_int_type, raw_ptr, nelem, dim=1):
|
|
if raw_ptr is None:
|
|
return None
|
|
|
|
import numpy as np
|
|
np_int_type = self._ctype_to_numpy_int(c_int_type)
|
|
|
|
if dim == 1:
|
|
ptr = cast(raw_ptr, POINTER(c_int_type * nelem))
|
|
else:
|
|
ptr = cast(raw_ptr[0], POINTER(c_int_type * nelem * dim))
|
|
|
|
a = np.frombuffer(ptr.contents, dtype=np_int_type)
|
|
|
|
if dim > 1:
|
|
a.shape = (nelem, dim)
|
|
else:
|
|
a.shape = (nelem)
|
|
return a
|
|
|
|
# -------------------------------------------------------------------------
|
|
|
|
def darray(self, raw_ptr, nelem, dim=1):
|
|
if raw_ptr is None:
|
|
return None
|
|
|
|
import numpy as np
|
|
|
|
if dim == 1:
|
|
ptr = cast(raw_ptr, POINTER(c_double * nelem))
|
|
else:
|
|
ptr = cast(raw_ptr[0], POINTER(c_double * nelem * dim))
|
|
|
|
a = np.frombuffer(ptr.contents)
|
|
|
|
if dim > 1:
|
|
a.shape = (nelem, dim)
|
|
else:
|
|
a.shape = (nelem)
|
|
return a
|
|
|
|
# -------------------------------------------------------------------------
|
|
|
|
class NumPyNeighList(NeighList):
|
|
"""This is a wrapper class that exposes the contents of a neighbor list.
|
|
|
|
It can be used like a regular Python list. Each element is a tuple of:
|
|
|
|
* the atom local index
|
|
* a NumPy array containing the local atom indices of its neighbors
|
|
|
|
Internally it uses the lower-level LAMMPS C-library interface.
|
|
|
|
:param lmp: reference to instance of :py:class:`lammps`
|
|
:type lmp: lammps
|
|
:param idx: neighbor list index
|
|
:type idx: int
|
|
"""
|
|
def __init__(self, lmp, idx):
|
|
super(NumPyNeighList, self).__init__(lmp, idx)
|
|
|
|
def get(self, element):
|
|
"""
|
|
Access a specific neighbor list entry. "element" must be a number from 0 to the size-1 of the list
|
|
|
|
:return: tuple with atom local index, numpy array of neighbor local atom indices
|
|
:rtype: (int, numpy.array)
|
|
"""
|
|
iatom, neighbors = self.lmp.numpy.get_neighlist_element_neighbors(self.idx, element)
|
|
return iatom, neighbors
|
|
|
|
def find(self, iatom):
|
|
"""
|
|
Find the neighbor list for a specific (local) atom iatom.
|
|
If there is no list for iatom, None is returned.
|
|
|
|
:return: numpy array of neighbor local atom indices
|
|
:rtype: numpy.array or None
|
|
"""
|
|
inum = self.size
|
|
for ii in range(inum):
|
|
idx, neighbors = self.get(ii)
|
|
if idx == iatom:
|
|
return neighbors
|
|
return None
|