Cblacs2sys_handle is insufficient

[naromero]

Hi,

I keep posting this to the ScaLAPACK forum but it keeps disappearing. I wonder if there are problems with
the website.

When a BlacsGrid is created via a call to blacs_gridmap, it looks like at least three communicators are created:

1. MPI communicator for scope = 'all'
2. MPI communicator for scope = 'row'
3. MPI communicator for scope = 'Column'

From the look of the BLACSCONTEXT structure in Bdef.h, maybe there is also a pt2pt scope?

It would be much better if Cblacs2sys_handle actually returned all these different communicators.
I am not sure what it returns right now, but its is not seem to be to useful.

I think it is important to exposes these communicators to application developers that are using ScaLAPACK. It
will help them interface ScaLAPACK better with other MPI functionality. I would be willing to to
write such a routine and submit it to the developers *if* they are willing to integrate it into ScaLAPACK.

Nichols A. Romero
Argonne Leadership Computing Facility

[admin]

Thank you Nichols,
we are always delighted to have user's contribution and to integrate it into the ScaLAPACK project.
You can have a look at http://www.netlib.org/lapack-dev/lapack ... style.html if you are willing to contribute to the project.
Regards,
Julie