Classes | |
struct | AdditionalData |
Public Member Functions | |
void | initialize (const SparseMatrix &matrix, const AdditionalData &additional_data=AdditionalData()) |
Private Attributes | |
Teuchos::RCP < Ifpack_Preconditioner > | ifpack |
ic_fill
, so one can gradually choose between a factorization on the sparse matrix structure only (ic_fill=0
) to a full factorization (ic_fill
in the range of 10 to 50, depending on the spatial dimension of the PDE problem and the degree of the finite element basis functions; generally, more required fill-in elements require this parameter to be set to a higher integer value).
The AdditionalData data structure allows to set preconditioner options. Besides the fill-in argument, these options are some options for perturbations (see the documentation of the AdditionalData structure for details), and a parameter overlap
that determines if and how much overlap there should be between the matrix partitions on the various MPI processes. The default settings are 0 for the additional fill-in, 0 for the absolute augmentation tolerance, 1 for the relative augmentation tolerance, 0 for the overlap.
Note that a parallel applicatoin of the IC preconditioner is actually a block-Jacobi preconditioner with block size equal to the local matrix size. Spoken more technically, this parallel operation is an additive Schwarz method with an IC approximate solve as inner solver, based on the (outer) parallel partitioning.
void TrilinosWrappers::PreconditionIC::initialize | ( | const SparseMatrix & | matrix, | |
const AdditionalData & | additional_data = AdditionalData() | |||
) |
Initialize function. Takes the matrix the preconditioner should be computed of, and additional flags if there are any.
Teuchos::RCP<Ifpack_Preconditioner> TrilinosWrappers::PreconditionIC::ifpack [private] |
This is a pointer to the Ifpack data contained in this preconditioner.