NOX  Development
 All Classes Namespaces Files Functions Variables Typedefs Enumerations Enumerator Friends Groups Pages
NOX & LOCA: Object-Oriented Nonlinear Solver and Continuation Packages


NOX is short for Nonlinear Object-Oriented Solutions, and its objective is to enable the robust and efficient solution of the equation: $ F(x)=0 $, where $F:\Re^n \rightarrow \Re^n$. NOX implements a variety of Newton-based globalization techniques including Line Search and Trust Region algorithms. In additon it provides higher and lower order models using Broyden and Tensor algorithms. Special algorithms have been developed for use with inexact linear solvers such as Krylov subspace techniques. 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 $ F(x,p)=0 $ and their bifurcations, where $F:\Re^n\times\Re^m\rightarrow\Re^n$. For LOCA specific information, see LOCA Overview.


NOX/LOCA version 10.2 will be released as part of Trilinos 10.2 in March 2010. Please read the NOX and LOCA Release Information (Last updated March 1st 2010) page for more details on these changes.

Technical Information


NOX is available for download under the terms of the GNU Lesser General Public License.


NOX and LOCA are packaged and released as part of the Trilinos Solver Framework. You may download NOX (which includes LOCA) by downloading a copy of Trilinos. Please see the Trilinos downloads page for the latest releases.

Reporting Bugs and Making Enhancement Requests

To reports bugs or make enhancement requests, visit the Trilinos Bugzilla (Bug Tracking) Database, and use the following instructions.

Mailing Lists

We recommend that users and developers subscribe to the following mailing lists as appropriate.

NOX & LOCA Contributors

The following people have contributed code to NOX and/or LOCA:

For All Other Questions and Comments...

Please contact Roger Pawlowski ( or Eric Phipps (