Abstract
In this talk, we give an overview of the Trilinos project. We'll
discuss the overall design and available capabilities, as well as future plans.
Particular emphasis will be on recent additions to the Trilinos package family.
New and potential users are encouraged to attend.
Abstract
Sundance is a Trilinos package containing components for building parallel PDE
simulations. This talk will give an overview of Sundance with examples of
setting up complex multiphysics simulations and accessing Trilinos solvers.
Abstract
The Trilinos Stratimikos package provides an aggregated,
parameter-list-driver, "Facade" class for access to many of the
linear solver and preconditioner capabilities such as in the Trilinos packages
Amesos, AztecOO, Belos, Ifpack, and ML. All you need is an Epetra_Operator
and/or (even better) an Epetra_RowMatrix object for the defining matrix,
Epetra_[Multi]Vector objects for the RHS and LHS, and a parameter list (read in
from an XML file, from the command line, or set in code) and you can then
access a significant serial and parallel, direct and iterative, linear solver
capability. This talk will describe the real foundation for the Stratimikos
interface design which is Thyra. Thyra is a set of abstract interfaces for
vectors, vector spaces, linear operators, linear solvers, and preconditioners
that support the development of advanced abstract numerical algorithms (ANAs).
In addition, Thyra also defines an interface to nonlinear
simulation-constrained models called the ModelEvaluator that was (and still is)
a major driver for the development of Stratimikos. However, Stratimikos can be
used by less abstract clients by converting to and from Epetra and Thyra
objects.
Abstract
The solution of very large and sparse linear systems with multiple right-hand
sides is often required in modeling and simulation. While many numerical
methods for solving these linear systems have been proposed in the literature,
Belos provides an iterative linear solver framework for developing and
delivering these methods to application codes. In this talk we will discuss
interacting with Belos, from a user and developer standpoint, and the
available numerical methods for solving both single and multiple right-hand
side linear systems.
Abstract
Meros is a segregated preconditioning package that provides scalable
block preconditioning for problems that couple simultaneous solution
variables. Our initial focus has been on methods for solution of the
incompressible Navier-Stokes equations. Meros is available as part of
the Trilinos Project. This talk will give
an overview of the capabilities currently available in Meros as well as
plans for future development.
Abstract
We focus on several new algorithmic capabilities introduced in ML,
Trilinos' multilevel solvers package. The first capability is a new
multilevel solver for compatible discretizations (edge elements) of the
eddy current Maxwell's equations. This new solver, made available in
Trilinos 8.0, is based on an algebraic reformulation of the discrete
system, and has demonstrated successful weak parallel scaling up to 24,000
processors and 658 million unknowns.
The second capability enhances ML's existing repartitioning routines
through the hypergraph repartitioning available through Zoltan 3.0. The
new algorithm accurately models communication costs in both the setup and
iterative phases to produce a better processor repartitioning. This
feature is currently under development and will be released in Trilinos 9.0
in the fall.
We will also discuss some practical improvements designed to improve
the ML user experience, including validation of user input parameters.