[Trilinos-Users] Epetra Vectors/Maps

[Williams, Alan B]

Yes I think that for your case you would pass in NumGlobalElements == -1.
Alan

> -----Original Message-----
> From: trilinos-users-bounces at software.sandia.gov [mailto:trilinos-
> users-bounces at software.sandia.gov] On Behalf Of John Mitchell
> Sent: Friday, January 29, 2010 4:56 PM
> To: trilinos-users at software.sandia.gov
> Subject: Re: [Trilinos-Users] Epetra Vectors/Maps
> 
> Thanks Alan and Mike.
> 
> The reason I was asking is because the documentation says:
> 
>     \param In
>             NumGlobalElements - Number of elements to distribute.  Must
> be
>      either -1 or equal to the computed sum of NumMyElements across all
>      processors in the Epetra_Comm communicator.
> 
> This documentation must not be correct or I'm reading it the wrong way?
> 
> Thanks,
> John
> 
> Williams, Alan B wrote:
> > Hi John,
> >
> > Yes you can have vectors/maps that overlap in the way that you
> describe. We have finite-element codes that use epetra in exactly that
> way.
> >
> > Alan
> >
> >
> >
> >> -----Original Message-----
> >> From: trilinos-users-bounces at software.sandia.gov [mailto:trilinos-
> >> users-bounces at software.sandia.gov] On Behalf Of John Mitchell
> >> Sent: Friday, January 29, 2010 4:38 PM
> >> To: trilinos-users at software.sandia.gov
> >> Subject: [Trilinos-Users] Epetra Vectors/Maps
> >>
> >> I am new to the use of Epetra and have a couple basic questions that
> >> don't appear to be directly addressed in the tutorial.
> >>
> >> Is it possible to create an
> >>
> >> Epetra_Map(numGlobalElements,numMyElements,myElements,0,comm)
> >>
> >> where sum(numMyElements) over all processors != numGlobalElements?
> >>
> >> What I have, is a list of ids that I own, and then a list of ids
> that I
> >> share but don't own.  I need to do parallel calculations and
> assemblies
> >> on a vector that is of length numOwned+numShared.  Assembly
> operations
> >> for both owned and shared may require off-processor communications.
> I
> >> have a vector f = {f_owned, f_shared}; If a point that is owned on
> >> processor is shared on another processor, then the assembly of
> f_owned
> >> will require contributions f_shared from the sharing off processor
> >>
> >> I was planning on using the above Epetra_Map as a target map for
> >> creating an Epetra_Import -- does that make sense?
> >>
> >> Thanks,
> >> John
> >>
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> >>
> 
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