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AZTEC: A parallel iterative package for the solving linear systems

Authors: Scott A. Hutchinson, John N. Shadid, Ray S. Tuminaro
Speaker: Scott A. Hutchinson
MS 1110
Sandia National Labs
PO Box 5800
Albuquerque, NM 87185
We describe a parallel linear system package, AZTEC. The package
incorporates a number of parallel iterative methods (e.g. GMRES, biCGSTAB,
CGS, TFQMR) and preconditioners (e.g. Jacobi, Gauss-Seidel, polynomial,
domain decomposition with LU or ILU within subdomains). Additionally, AZTEC
allows for the reuse of previous preconditioning factorizations within
Newton schemes for nonlinear methods. Currently, a number of different
users are using this package to solve a variety of PDE applications.
In this talk we emphasize the parallel programming ease and the overall
efficiency of AZTEC. Ease-of-use is attained using the notion of a global
distributed matrix. The global distributed matrix allows a user to specify
pieces (different rows for different processors) of an application matrix
exactly as in the serial setting. Efficiency is achieved by using a
transformation function which rewrites the user supplied matrix into
one more convenient for efficient distributed memory computing (locally
numbered entries, ghost variables, grouped messages). Additional performance
is attained using efficient dense matrix algorithms for block sparse matrices.
AZTEC can be used on the Intel Paragon, nCUBE 2, IBM SP2, individual
workstations (e.g. SUN and SGI) and uses the MPI message passing system.