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Subject: Re: [OMPI users] Allgather in inter-communicator bug,
From: Battalgazi YILDIRIM (yildirimga_at_[hidden])
Date: 2010-05-20 09:43:27


Hi Jody,

I think that it is correct, you can test this example in your desktop,

thanks,

On Thu, May 20, 2010 at 3:18 AM, jody <jody.xha_at_[hidden]> wrote:

> Hi
> I am really no python expert, but it looks to me as if you were
> gathering arrays filled with zeroes:
> a = array('i', [0]) * n
>
> Shouldn't this line be
> a = array('i', [r])*n
> where r is the rank of the process?
>
> Jody
>
>
> On Thu, May 20, 2010 at 12:00 AM, Battalgazi YILDIRIM
> <yildirimga_at_[hidden]> wrote:
> > Hi,
> >
> >
> > I am trying to use intercommunicator ::Allgather between two child
> process.
> > I have fortran and Python code,
> > I am using mpi4py for python. It seems that ::Allgather is not working
> > properly in my desktop.
> >
> > I have contacted first mpi4py developers (Lisandro Dalcin), he
> simplified
> > my problem and provided two example files (python.py and fortran.f90,
> > please see below).
> >
> > We tried with different MPI vendors, the following example worked
> correclty(
> > it means the final print out should be array('i', [1, 2, 3, 4, 5, 6, 7,
> 8])
> > )
> >
> > However, it is not giving correct answer in my two desktop (Redhat and
> > ubuntu) both
> > using OPENMPI
> >
> > Could yo look at this problem please?
> >
> > If you want to follow our discussion before you, you can go to following
> > link:
> >
> http://groups.google.com/group/mpi4py/browse_thread/thread/c17c660ae56ff97e
> >
> > yildirim_at_memosa:~/python_intercomm$ more python.py
> > from mpi4py import MPI
> > from array import array
> > import os
> >
> > progr = os.path.abspath('a.out')
> > child = MPI.COMM_WORLD.Spawn(progr,[], 8)
> > n = child.remote_size
> > a = array('i', [0]) * n
> > child.Allgather([None,MPI.INT],[a,MPI.INT])
> > child.Disconnect()
> > print a
> >
> > yildirim_at_memosa:~/python_intercomm$ more fortran.f90
> > program main
> > use mpi
> > implicit none
> > integer :: parent, rank, val, dummy, ierr
> > call MPI_Init(ierr)
> > call MPI_Comm_get_parent(parent, ierr)
> > call MPI_Comm_rank(parent, rank, ierr)
> > val = rank + 1
> > call MPI_Allgather(val, 1, MPI_INTEGER, &
> > dummy, 0, MPI_INTEGER, &
> > parent, ierr)
> > call MPI_Comm_disconnect(parent, ierr)
> > call MPI_Finalize(ierr)
> > end program main
> >
> > yildirim_at_memosa:~/python_intercomm$ mpif90 fortran.f90
> >
> > yildirim_at_memosa:~/python_intercomm$ python python.py
> > array('i', [0, 0, 0, 0, 0, 0, 0, 0])
> >
> >
> > --
> > B. Gazi YILDIRIM
> >
> > _______________________________________________
> > users mailing list
> > users_at_[hidden]
> > http://www.open-mpi.org/mailman/listinfo.cgi/users
> >
>
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>

-- 
B. Gazi YILDIRIM