The Linear System Analyzer
The Linear System Analyzer (LSA) is a dual goal research project.
One goal is a problem solving environment (PSE) for solving large, sparse,
unstructured linear systems of equations which occur in computational
science and engineering problems. This problem
domain, and the need for a PSE to handle it, are described later. The
second LSA project goal is research into and development of PSE infrastructure
tools, by providing reusable PSE subsystems and by creating a component
architecture for scientific computing. The LSA provides one focus (or "point
solution") for the PSE research, while the PSE research provides the mechanisms
which enable the LSA.
The work is part of the PSEware project ,
an NSF-funded joint research project with Drexel, CalTech, UC Irvine,
and Los Alamos National Laboratory.
The LSA project has evolved into the
whose aim is to develop a component-based software toolkit designed to
facilitate the construction of high-performance scientific applications that
can efficiently operate in heterogeneous distributed computing environments.
The word "component" has an English language meaning
of "part", but here we will only use it for the specific meaning
of a software component. We give a definition of "component"
and explanation of the relationship of the LSA and
However, the role of component systems in scientific computing is
still a developing area.
The LSA architecture consists of four modular subsystems, each with its own
- User control and interface
- State save/restore
- Framework manager
- Resource database management
- Component instance ID
- Collaboration (planned)
- Communications subsystem
- Nexus communication library
- HPC++ wrapper interface
- NexusJava GUI/Manager protocol
- Information subsystem
- Component framework statistics (juan)
- Error/exception handling (tom)
- Component-specific (tom)
The HPC++ wrapper code
for the LSA modules is available for browsing.
The problem domain addressed
by the LSA is large, sparse linear systems of equations. This is
a common and difficult subproblem for many scientific and engineering
computations, making it a useful target.
The actual computational components
currently in the LSA include I/O, filters, and solvers. The set is
not exhaustive, but provides at least one example of each kind of
operation typically done with sparse matrices.
The target audience or user model
for the LSA is multilevel, as is appropriate for component systems.
The levels include expert researchers in numerical linear algebra,
scientists and engineers who need to experiment with sparse linear
systems, and students.
The actual LSA usage model
is a visual programming, data flow model.
Finally, future developments
for the LSA include several extensions: adding new components,
providing Globus and possibly Netsolve resource management, etc.
As part of the PSEware project, the LSA uses tools, techniques, and ideas
from several participating institutions, and the
PSEware home page has the full list of those
participants. The LSA is an Indiana University component of that overall
project, and the primary IU-affiliated researchers working on the LSA are:
A PSEware alumnus who built an Iris Explorer system ancestral to the LSA
Papers and Conferences
Below is a selected list of papers and conferences which featured
the PSE LSA system.
- Java98 ACM Conference held in Palo Alto, CA. Presentation given by Juan Villacis .
- Java RMI Performance and
Object Model Interoperability:
Experiments with Java/HPC++,
Fabian Breg, Shridhar Diwan, Juan Villacis,
Jayashree Balasubramanian, Esra Akman, and Dennis Gannon.
Concurrency and Experience, 1998.
- Component Architectures for
Distributed Scientific Problem Solving,
D. Gannon, R. Bramley, T. Stuckey, J. Villacis,
J. Balasubramanian, E. Akman, F. Breg, S. Diwan, and
M. Govindaraju. Accepted for the Special Issue of
IEEE CS&E Magazine on Languages for Computational Science
and Engineering, April-June 1998.
- The Linear System
Analyzer, R. Bramley, D. Gannon, T. Stuckey, J.
Villacis, J. Balasubramanian, E. Akman, F. Breg, S. Diwan, and
M. Govindaraju. Submitted for IEEE book on PSEs,
The Linear System Analyzer: A Prototype Distributed Component
System , part of a Workshop on
Component Frameworks and Solver Interoperability Requirements
, at the
Colorado Conference on Iterative Methods.
Primary funding is from the CISE
directorate of the National Science Foundation,
as grant number CCR-9527130. Additional
funding support comes from the NSF grant ASC-9502292
, Partial Orthogonalization Methods in Scientific Computing.
Center for Simulating Dynamic Response of Materials
is also providing support for the component architecture research.
Next page: Component architectures
and the LSA
Last updated: Tue Jan 26 12:55:40 1999