mpipi2.py 1.1 KB
 Neil Gershenfeld committed Feb 06, 2020 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 ``````# # mpipi2.py # Neil Gershenfeld 2/6/20 # calculation of pi by an MPI Numba sum # pi = 3.14159265358979323846 # import time from numba import jit from mpi4py import MPI NPTS = 1000000000 NLOOP = 10 comm = MPI.COMM_WORLD rank = comm.Get_rank() nproc = comm.Get_size() @jit(nopython=True) def calc(istart,iend): sum = 0.0 for i in range(istart,iend+1): sum += 0.5/((i-0.75)*(i-0.25)) return sum if (rank == 0): istart = 1+rank*NPTS; iend = (rank+1)*NPTS; max = 0 for j in range(NLOOP): comm.Barrier() start_time = time.time() sum = 0.0; sum = calc(istart,iend) pi = comm.reduce(sum,op=MPI.SUM,root=0) end_time = time.time() mflops = nproc*NPTS*5.0/(1.0e6*(end_time-start_time)) print("processes = %d, NPTS = %d, pi = %f"%(nproc,NPTS,pi)) if (mflops > max): max = mflops print("time = %f, estimated MFlops = %f, max = %f"%(end_time-start_time,mflops,max)) else: istart = 1+rank*NPTS iend = (rank+1)*NPTS for j in range(NLOOP): comm.Barrier() sum = calc(istart,iend) comm.reduce(sum,op=MPI.SUM,root=0)``````