[Trilinos-Users] NOX = Powell's Hybrid Method

[Roger Pawlowski]

Hi Donald,

Powell's method is similar to our "NonlinearCG" algorithm.  An example 
of how to use it is in:

Trilinos/packages/nox/test/epetra/1Dfem/1DfemNonlinearCG.C

For the trust region algorithm, the trust region solver builds a dogleg 
direction from two simple directions specified by the user.  The two 
directions are typically "Newton" and "Steepest Descent".  You set these 
by setting the "Newton" direction as the method in the "Direction" 
sublist and setting "Steepest Descent" as the method in the "Cauchy 
Direction" sublist.  An example of this can be found in:

Trilinos/packages/nox/test/epetra/1Dfem/1DfemScaledInexactTrustRegion.C

Best regards,
Roger Pawlowski

Kunz Donald L Civ AFIT/ENY wrote:
>
> What combination of NOX solver (Trust Region Based? or Inexact Trust 
> Region Based?) and parameters duplicate Powell's hybrid method?  I 
> tried Trust Region Based with Dogleg direction, but apparently Dogleg 
> isn't supported with that solver.  Any suggestions would be greatly 
> appreciated.
>
> // SIGNED //
>
> Donald L. Kunz, Ph.D., P.E.
> Associate Professor of Aerospace Engineering, AD-23
> Department of Aeronautics & Astronautics
> Air Force Institute of Technology
> 2950 Hobson Way, AFIT/ENY
> Wright-Patterson AFB, OH  45458-7765
> Phone: 937-255-3636 x4548 (DSN 785)
> Fax: 937-656-7053 (DSN 986)
>