//HelloWorldMPI, from John Urbanic psc slides

#include <stdio.h>
#include "mpi.h"

int main(int argc, char **argv)
{
    int my_PE_num;
    MPI_Init(&argc, &argv);
    MPI_Comm_rank(MPI_COMM_WORLD, &my_PE_num);
    printf("Hello from %d.\n", my_PE_num);
    MPI_Finalize();
    return 0;
}

/*
MPICH version on the workstations:
mpicc.mpich -o helloWorldMpi helloWorldMpi.c

mpirun -np 4 -all-local helloWorldMPI   (we're using only one workstation for now)


(enter password 3 times)

Hello from 0.
Hello from 2.
Hello from 1.
Hello from 3.

CRAY SV1:

cc helloWorldMPI.c 

mpirun -np 4 a.out        
Hello from 0.
Hello from 2.
Hello from 3.
Hello from 1.

mpirun -np 16 a.out
Hello from 0.
Hello from 1.
Hello from 2.
Hello from 3.
Hello from 4.
Hello from 5.
Hello from 6.
Hello from 8.
Hello from 9.
Hello from 10.
Hello from 7.
Hello from 11.
Hello from 13.
Hello from 14.
Hello from 15.
Hello from 12.

*/