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#!/usr/bin/env python
# If you want VampirTrace to log MPI calls, you have to add the two
# lines below at the very beginning of your main bootstrap script.
import mpi4py.rc
mpi4py.rc.threaded = False
mpi4py.rc.profile('vt-mpi', logfile='cpilog')
# Import the MPI extension module
from mpi4py import MPI
# Import the 'array' module
from array import array
# This is just to make the logging
# output a bit more interesting
from time import sleep
comm = MPI.COMM_WORLD
nprocs = comm.Get_size()
myrank = comm.Get_rank()
n = array('i', [0])
pi = array('d', [0])
mypi = array('d', [0])
def comp_pi(n, myrank=0, nprocs=1):
h = 1.0 / n;
s = 0.0;
for i in range(myrank + 1, n + 1, nprocs):
x = h * (i - 0.5);
s += 4.0 / (1.0 + x**2);
return s * h
comm.Barrier()
for N in [10000]*10:
if myrank == 0:
n[0] = N
comm.Bcast([n, MPI.INT], root=0)
mypi[0] = comp_pi(n[0], myrank, nprocs)
comm.Reduce([mypi, MPI.DOUBLE],
[pi, MPI.DOUBLE],
op=MPI.SUM, root=0)
comm.Barrier()
sleep(0.01)
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