Ifpack2: Do we really need Filters?
Created by: mhoemmen
@trilinos/ifpack2 @jhux @csiefer2
Any optimized subdomain solver that depends on the structure of the matrix -- e.g., sparse LU or ILU* -- will want to access the data structures directly. For example, Ifpack2's ILU(k) or ILUT all take the input RowMatrix -- which may perhaps be a LocalFilter -- and convert it to a CrsMatrix, if it is not already a CrsMatrix.
This makes me wonder why we need Filters. It's just another layer between the subdomain solver and its data. RowMatrix is still a good idea; if a solver needs a CrsMatrix, it can always copy the RowMatrix into a CrsMatrix.