I think we should extract them the same way as SNESMFFD. Using them as a PC is a good idea.
Matt On Tue, Aug 30, 2016 at 1:18 PM, Munson, Todd <tmun...@mcs.anl.gov> wrote: > > One of the common concepts for TAO and SNES is the quasi-Newton > approximations. > SNES seems to only use them in SNESQN (for non-symmetric matrices) and TAO > uses > them in TAOLMVM and TAOBLMVM (for symmetric matrices). TOA also allows > them to > be used as a preconditioner for the Hessian-based line-search and > trust-region > methods. > > Should we consider extracting some common class for these approximations > and > the associated operations or just leave them as separate things? > > Todd. > > -- What most experimenters take for granted before they begin their experiments is infinitely more interesting than any results to which their experiments lead. -- Norbert Wiener