Matrix Storage Format

Matrix storage format = {msr | vbr}

Description / Usage

This optional card can be used to choose between two formats accepted by the Aztec 2.1 solver package. Valid options are:

msr

modified sparse row format (see Schunk and Shadid, 1992). This option is the default option and is automatically used for all direct solver options.

vbr

variable block row format (see Heroux, 1992). This option should only be selected when an Aztec iterative solver is chosen.

epetra

Compressed Sparse Row format using the Epetra library from Trilinos

tpetra

FECRSMatrix Compressed Sparse Row format using the Tpetra library from Trilinos currently only works using Stratimikos and Amesos2

Examples

Following is a sample card:

Matrix storage format = msr

Technical Discussion

Goma supports two global matrix formats for its linear solvers. The advantage of choosing vbr over the default msr format is a matter of which preconditioner option is selected. (See Schunk, et al., 2002 on iterative methods.) When using the front solver package, another format known as estifm is employed internally but not specified by this card, which is not used in this case.

References

SAND92-1158: Iterative Solvers in Implicit Finite Element Codes, Sandia Technical Report, Schunk, P. R. and Shadid, J. N. (1992)

SAND2001-3512J: Iterative Solvers and Preconditioners for Fully-coupled Finite Element Formulations of Incompressible Fluid Mechanics and Related Transport Problems, P. R. Schunk, M. A. Heroux, R. R. Rao, T. A. Baer, S. R. Subia and A. C. Sun, March 2002.

TR/PA/92/90: M. A. Heroux, A proposal for a sparse BLAS toolkit, Technical Report, CERFACS, December 1992.