[Dune] How to get a unique index?

[Markus Blatt]

Hi,

On Fri, Jan 26, 2007 at 11:09:00AM +0100, Patrick Leidenberger wrote:
> Hi Markus
> 
> > 
> >> I want to make a unique list of entities over all processes.
> >>
> > 
> > Does that mean you want to store all global ids on one process?
> > I can't see why someone wants to do this.
> If I want to write from all processes to a single hdf5 data set I think
> the data attached to an entity should be unique.
> 

I guess you need this to write data for an entity just once right?

This means you need a disjoint partitioning of your entities. This can
be done rather easy:

Start with the process being master for all entities in
interior+border, slave for all others. Now send some dummy data
(e.~g.) process number form interior+border to interior+border, to see
who else knows your entities, and simply say that the process is the
master if it has the smallest rank of all processes knowing the entity
is stays master otherwise it becomes slave for that entity.

Now all master enties form a disjoint partitioning.

Markus