# abcpmc 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.
#
# abcpmc 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 abcpmc. If not, see <http://www.gnu.org/licenses/>.
import itertools
try:
from mpi4py import MPI
MPI = MPI
except ImportError:
MPI = None
__all__ = ["MpiPool", "mpiBCast"]
[docs]class MpiPool(object):
def __init__(self, mapFunction=map):
self.rank = MPI.COMM_WORLD.Get_rank()
self.size = MPI.COMM_WORLD.Get_size()
self.mapFunction = mapFunction
[docs] def map(self, function, sequence):
(rank,size) = (MPI.COMM_WORLD.Get_rank(),MPI.COMM_WORLD.Get_size())
sequence = mpiBCast(sequence)
mergedList = _mergeList(MPI.COMM_WORLD.allgather(
self.mapFunction(function, _splitList(sequence,size)[rank])))
return mergedList
[docs] def isMaster(self):
"""
Returns true if the rank is 0
"""
return (self.rank==0)
[docs]def mpiBCast(value):
"""
Mpi bcasts the value and returns the value from the master (rank = 0).
"""
return MPI.COMM_WORLD.bcast(value)
def _splitList(list, n):
blockLen = len(list) / float(n)
return [list[int(round(blockLen * i)): int(round(blockLen * (i + 1)))] for i in range(n)]
def _mergeList(lists):
return list(itertools.chain(*lists))