[SciPy-user] Parallel OO programming in Python.

[Brian Granger]

> I also looked at the entry on Ipython1 and it looks really promising.
> Did I understand correctly that Ipython1 is able to run parallel python
> code, regardless of which "MPI for python" package one eventually uses?

In principle yes.  The IPython engines have a configuration option
that you use to import the mpi bindings of your choice.  But, to work
properly, the import statement must cause MPI_Init() to be called.  If
the bindings you are using don't do that, it should b easy to write a
wrapper module that imports and also calls MPI_Init().  Also, some of
this depends on what MPI implementation you are using.  The more
moderns ones (like openmpi) are really nice and pretty forgiving.  The
older ones, though, sometimes require that Python itself (not your
script) call MPI_Init().  This is also very easy to work around.  The
bottom line is that we can help you get it to work with whatever mpi
binding and implementation you want.

Withh that said, I highly do highly recommend mpi4py and openmpi - we
use these regularly with ipython and it all works well.

Brian


> Giovanni
>
> Flavio Coelho wrote:
> > Thank you for this post and many thanks to Fernando Perez, for the
> > awesome tool that Ipython1 is becomming!!! I am beginning to use it
> > today!!
> >
> > Flávio
> >
> > On 10/29/06, * Brian Granger* <ellisonbg.net at gmail.com
> > <mailto:ellisonbg.net at gmail.com>> wrote:
> >
> >     > For object oriented parallel programming in Python on a single
> >     machine I can use techniques such as Bulk Synchronous Parallelism
> >     (BSP) or Message Passing Interface (MPI). There are mentioned some
> >     modules and packages for Python on
> >     > http://www.scipy.org/Topical_Software
> >     > Article: Parallel and distributed programming.
> >     > After reading prerequisites and limitations I thing that the
> >     following ones could be good for me:
> >     > PyMPI
> >     > Pypar
> >     > MPI for Python
> >
> >     I think mpi4py is the best option.  It is a very nice implementation
> >     and the developer is working really hard to make it a great package.
> >     Also, I don't think pympi and pypar are being developed actively
> >     anymore.
> >
> >     Another thing you might check out is IPython's parallel computing
> >     facilities that let you use mpi4py (and other mpi bindings)
> >     interactively:
> >
> >     http://ipython.scipy.org/moin/Parallel_Computing
> >
> >     I have never used BPS, but am familiar with the model.  Can probably
> >     get it working interactively with IPython as well.
> >
> >     Cheers,
> >
> >     Brian
> >
> >     > But I can't distinguish which one brings fewer limitations, is
> >     efficient in application and will develop in future.
> >     > My favorite is BSP, but I can't find a package for present SciPy
> >     and NumPy.
> >     >
> >     > Could anybody give me a recommendation, which way I should go.
> >     >
> >     > Thanks.
> >     > Fie Pye
> >     >
> >     >
> >     >
> >     >
> >     > ---------------------------------------
> >     > Máme další spot P.Čtvrtníčka. Podívejte se www.neuservis.cz
> >     <http://www.neuservis.cz>
> >     >
> >     >
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> >
> >
> > --
> > Flávio Codeço Coelho
> > registered Linux user # 386432
> > ---------------------------
> > "Laws are like sausages. It's better not to see them being made."
> > Otto von Bismark
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