Page MenuHomec4science
Files F61923613

fft.py
No OneTemporary
Actions

File Metadata

Created
Thu, May 9, 20:29

fft.py
View Options

#
# @file fft.py
#
# @author Lars Pastewka <lars.pastewka@imtek.uni-freiburg.de>
#
# @date 27 Mar 2018
#
# @brief Wrapper for muSpectre's FFT engines
#
# Copyright © 2018 Till Junge
#
# µSpectre 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, or (at
# your option) any later version.
#
# µSpectre 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 GNU Emacs; see the file COPYING. If not, write to the
# Free Software Foundation, Inc., 59 Temple Place - Suite 330,
# Boston, MA 02111-1307, USA.
#
try:
from mpi4py import MPI
except ImportError:
MPI = None
import _muSpectre
_factories = {'fftw': ('FFTW_2d', 'FFTW_3d', False),
'fftwmpi': ('FFTWMPI_2d', 'FFTWMPI_3d', True),
'pfft': ('PFFT_2d', 'PFFT_3d', True),
'p3dfft': ('P3DFFT_2d', 'P3DFFT_3d', True)}
def FFT(resolutions, lengths, fft='fftw', communicator=None):
"""
Instantiate a muSpectre FFT class.
Parameters
----------
resolutions: list
Grid resolutions in the Cartesian directions.
lengths: list
Physical size of the cell in the Cartesian directions.
fft: string
FFT engine to use. Options are 'fftw', 'fftwmpi', 'pfft' and 'p3dfft'.
Default is 'fftw'.
communicator: mpi4py communicator
mpi4py communicator object passed to parallel FFT engines. Note that
the default 'fftw' engine does not support parallel execution.
Returns
-------
cell: object
Return a muSpectre Cell object.
"""
if len(resolutions) != len(lengths):
raise ValueError("'resolutions' and 'lengths' must have identical "
"lengths.")
try:
factory_name_2d, factory_name_3d, is_parallel = _factories[fft]
except KeyError:
raise KeyError("Unknown FFT engine '{}'.".format(fft))
if len(resolutions) == 2:
factory_name = factory_name_2d
elif len(resolutions) == 3:
factory_name = factory_name_3d
else:
raise ValueError('{}-d transforms are not supported'
.format(len(resolutions)))
try:
factory = _muSpectre.fft.__dict__[factory_name]
except KeyError:
raise KeyError("FFT engine '{}' has not been compiled into the "
"muSpectre library.".format(fft))
if is_parallel:
if MPI is None:
raise RuntimeError('Parallel solver requested but mpi4py could'
' not be imported.')
if communicator is None:
communicator = MPI.COMM_SELF
return factory(resolutions, lengths,
MPI._handleof(communicator))
else:
if communicator is not None:
raise ValueError("FFT engine '{}' does not support parallel "
"execution.".format(fft))
return factory(resolutions, lengths)

Event Timeline

c4science · Help