NOX & LOCA: Object-Oriented Nonlinear Solver and Continuation Packages
NOX is short for Nonlinear Object-Oriented Solutions, and its objective is to enable the efficient solution of the equation: , where . NOX is designed to work with any linear algebra package and to be easily customized. NOX is part of Sandia's Trilinos project.
LOCA, distributed as part of NOX, is short for Library of Continuation Algorithms, and its objective is to compute families of solutions to and their bifurcations, where . For LOCA specific information, see LOCA Overview.
7/22/2005: IMPORTANT! Over the next few months, NOX will be undergoing a major refactor. Some changes that you will see in the development branch and (possibly) in the release of Trilinos 6.0 in September 2005 include:
Makefile.export support. All packages in Trilinos are switching over to supply users with Makefiles that users can include in their own projects to quikly link to NOX/LOCA.
Non-optional dependence of NOX on another Trilinos package called Teuchos. Teuchos is a very light-weight and portable utility library that supplies reference counted smart pointers and a parameter list among other things. As a result of this dependency, we ask that from now on, you download and build nox Trilinos instead of just building the nox library separately. This requirement is further needed since the new testing tools sit at the top Trilinos level. As we switch to the new tools, users will need Trilinos scripts to run the nox tests.
Multivector support will be not be an option, but will be a permanent part of the library.
Build options will change. please run "configure --help" to see the new options.
8/29/2005: There currently is a portability issue with LOCA to the Solaris platform using the Sun Forte 7 compilers. LOCA builds on this platform but does not run correctly. It appears the problem is compiler related as the virtual table for some LOCA objects is not setup correctly. All of the LOCA examples and any LOCA tests involving continuation runs fail with a segmentation fault. It is not known whether LOCA runs correctly when built with version 10 of the Sun compilers. See bugzilla bug 1238 for more information on this issue.
8/29/2005: Many of the internals of LOCA are being rewritten to more fully support multi-parameter continuation, constraint tracking, higher-order predictors and advanced bifurcation algorithms. This process is mostly, but not fully complete. In the future, this new framework will completely replace the old framework, but for now both are available. Because the new framework is under development, most of the documentation corresponds to the old framework and therefore it is recommended that new users write their interface to the old framework. For a brief description of the new framework, see the New LOCA Framework page.
See NOX User Information
See NOX Developer Information
See NOX and LOCA Release Information
NOX is available for download under the terms of the GNU Lesser General Public License.
NOX is packaged and released as part of the Trilinos Solver Framework. You may download NOX (which includes LOCA) by downloading a copy of Trilinos. Click on the Downloads reference in the left sidebar from the Trilinos Home page:
To reports bugs or make enhancement requests, visit NOX's Bugzilla (Bug Tracking) Database, and use the following instructions.
We recommend that users and developers subscribe to the following mailing lists as appropriate.
The following people have contributed code to NOX and/or LOCA:
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Please contact Tammy Kolda (firstname.lastname@example.org) or Roger Pawlowski (email@example.com).
Brett Bader, Sandia National Labs, firstname.lastname@example.org
Russ Hooper, Sandia National Labs, email@example.com
Tammy Kolda, Sandia National Labs, firstname.lastname@example.org (NOX Project Lead)
Roger Pawlowski, Sandia National Labs, email@example.com (NOX Project Lead)
Eric Phipps, Sandia National Labs, firstname.lastname@example.org
Andy Salinger, Sandia National Labs, email@example.com (LOCA Project Lead)
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