[Trilinos-Users] MueLu: maps unique, same

[Jonathan Hu]

> Hi MueLu devs,
>
> I recently switched one of my apps from ML to MueLu and I'm reevaluating
> some design decisions I took back then. For example, I vaguely remember
> that the reason for me to have map importing/exporting going on here and
> there was that ML required me that row and column map are equal for a 
> given
> matrix, and that the map is unique.
> Are these requirements still active in MueLu?
>
> Cheers,
> Nico
Nico,

     I'm assume by "unique" you mean that the map is 1-to-1.  There's no 
such requirement on the column map of the matrix that you pass into the 
MueLu preconditioner constructor.  In fact, in most cases this won't be 
true.  I don't think we make any assumptions on the row map either, but 
usually we're working with an assembled matrix where the row map is 1-1.

Jonathan