On Fri, Feb 10, 2012 at 16:06, Dmitry Karpeev <[email protected]> wrote:

I'm not sure I follow. If a matrix has been created, its type has been set and it has been preallocated (e.g., MATMPIAIJ in ksp/ksp/examples/tutorials/ex2), it is not marked as assembled until after MatAssemblyEnd. Does it still make sense to duplicate it? In my opinion, it does.

MatDuplicateOption specifies what to copy, but all cases are supposed to provide a correct nonzero pattern.