The Alltoall collective communication combines the scatter and gather functionalities.
Collective communication using Alltoall
How to do it...
In the following example, we'll see an mpi4py implementation of comm.Alltoall. We'll consider a communicator a group of processes, where each process sends and receives an array of numerical data from the other processes defined in the group:
- For this example, the relevant mpi4py and numpy libraries must be imported:
from mpi4py import MPI import numpy
- As in the previous example, we need to set the same parameters, comm, size, and rank:
comm = MPI.COMM_WORLD size = comm.Get_size() rank = comm.Get_rank()
- Hence, we must define the data that each process...