Source code for espressomd.io.mpiio
# Copyright (C) 2010-2019 The ESPResSo project
#
# This file is part of ESPResSo.
#
# ESPResSo is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# ESPResSo is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
from ..script_interface import PScriptInterface
[docs]class Mpiio:
"""MPI-IO object.
Used to output particle data using MPI-IO to binary files.
.. note::
See the :meth:`write` and :meth:`read` methods for documentation.
"""
def __init__(self):
self._instance = PScriptInterface(
"ScriptInterface::MPIIO::MPIIOScript")
[docs] def write(self, prefix=None, positions=False, velocities=False,
types=False, bonds=False):
"""MPI-IO write.
Outputs binary data using MPI-IO to several files starting with prefix.
Suffixes are:
- head: Information about fields that are dumped,
- pref: Information about processes: 1 int per process,
- id: Particle ids: 1 int per particle,
- pos: Position information (if dumped): 3 doubles per particle,
- vel: Velocity information (if dumped): 3 doubles per particle,
- typ: Type information (if dumped): 1 int per particle,
- bond: Bond information (if dumped): variable amount of data,
- boff: Bond offset information (if bonds are dumped): 1 int per particle.
.. note::
Do not read the files on a machine with a different architecture!
Parameters
----------
prefix : :obj:`str`
Common prefix for the filenames.
positions : :obj:`bool`, optional
Indicates if positions should be dumped.
velocities : :obj:`bool`, optional
Indicates if velocities should be dumped.
types : :obj:`bool`, optional
Indicates if types should be dumped.
bonds : :obj:`bool`, optional
Indicates if bonds should be dumped.
Raises
------
ValueError
If no prefix was given or none of the output fields are chosen.
"""
if prefix is None:
raise ValueError(
"Need to supply output prefix via 'prefix' argument.")
if not positions and not velocities and not types and not bonds:
raise ValueError("No output fields chosen.")
self._instance.call_method(
"write", prefix=prefix, pos=positions, vel=velocities, typ=types, bond=bonds)
[docs] def read(self, prefix=None, positions=False, velocities=False,
types=False, bonds=False):
"""MPI-IO read.
This function reads data dumped by :meth`write`. See the :meth`write`
documentation for details.
.. note::
The files must be read on the same number of processes that wrote
the data. The data must be read on a machine with the same
architecture (otherwise, this might silently fail).
"""
if prefix is None:
raise ValueError(
"Need to supply output prefix via 'prefix' argument.")
if not positions and not velocities and not types and not bonds:
raise ValueError("No output fields chosen.")
self._instance.call_method(
"read", prefix=prefix, pos=positions, vel=velocities, typ=types, bond=bonds)
mpiio = Mpiio()