[Trilinos-Users] Parallel Matrix Multiplication

[Mike Heroux]

Raj,

For dense LU, there is a package in Trilinos called Pliris.  It is a partial
wrapper around Sandia's High-performance Linpack solver.  It does not
include support for complex data types, but if you want a real-valued solver
and have good dense BLAS (basically DGEMM), this should be a very fast,
scalable solver.  For quite a few years, it was the fastest solver in the
world.

If you need support for dense matrix-vector or matrix-matrix multiplication,
the Epetra_MultiVector class does provide this for distributed objects, but
is not optimal for square nor near-square matrices on many processors, since
a multivector can only be distributed in one dimension.

Finally, the Epetra_VbrMatrix class can actually be used to construct
distributed dense matrices that have a 2D distribution, e.g., block-cyclic
distribution.  This is the most flexible approach and can be used optimally,
but requires a good understanding of Epetra's block maps and VbrMatrix
class.  Understanding these topics usually takes some time when first
getting started.

Mike

> -----Original Message-----
> From: Raj B [mailto:rajb at rice.edu] 
> Sent: Monday, May 15, 2006 9:57 AM
> To: maherou at sandia.gov
> Subject: Re: [Trilinos-Users] Parallel Matrix Multiplication
> 
> Thanks for that information, Mike. I was also wondering if 
> there is support planned for parallel dense-matrix operations 
> in Trilinos anytime soon. I am currently working with PLAPACK 
> for that purpose, but it would be nice to be able to use the 
> Trilinos infrastructure and design.
> 
> Thanks
> Raj
>