Sets the auxiliary matrix used by PCHPDDM for the concurrent GenEO eigenproblems at the finest level. As an example, in a finite element context with nonoverlapping subdomains plus (overlapping) ghost elements, this could be the unassembled (Neumann) local overlapping operator. As opposed to the assembled (Dirichlet) local overlapping operator obtained by summing neighborhood contributions at the interface of ghost elements.
- preconditioner context
- index set of the local auxiliary, e.g., Neumann, matrix