Hello World MPI Examples

  4 most used MPI functions/subroutines

/* C Example */
#include <stdio.h>
#include <mpi.h>

int main (argc, argv)
int argc;
char *argv[];
int rank, size;

MPI_Init (&argc, &argv); /* starts MPI */
MPI_Comm_rank (MPI_COMM_WORLD, &rank); /* get current process id */
MPI_Comm_size (MPI_COMM_WORLD, &size); /* get number of processes */
printf( "Hello world from process %d of %d\n", rank, size );
return 0;

c  Fortran example  
program hello

include 'mpif.h'
integer rank, size, ierror, tag, status(MPI_STATUS_SIZE)

call MPI_INIT(ierror)
call MPI_COMM_SIZE(MPI_COMM_WORLD, size, ierror)
call MPI_COMM_RANK(MPI_COMM_WORLD, rank, ierror)
print*, 'node', rank, ': Hello world'
call MPI_FINALIZE(ierror)

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hello_world_ex.src  last modified Feb 14, 2011 Introduction Table of Contents
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