On Wed, Feb 14, 2018 at 6:43 PM, Smith, Barry F. <bsm...@mcs.anl.gov> wrote:
> > Hmm, > > 1) make sure you call PetscOptionsSetValue() before you call to > SNESSetFromOptions() > > 2) make sure you call SNESSetFromOptions() > > 3) did you add a prefix to the SNES object? If so make sure you include it > in the PetscOptionsSetValue() call. > > I can't see a reason why it won't work. Does it work with the PETSc > examples for you or not? > > Regarding the Powell descent option, I'm afraid you'll need to examine > the code for exact details. src/snes/impls/qn/qn.c Here is the description https://bitbucket.org/petsc/petsc/src/939b553f045c5ba32242d0d49e80e4934ed3bf76/src/snes/impls/qn/qn.c?at=master&fileviewer=file-view-default#qn.c-451 Thanks, Matt > > Barry > > > > On Feb 14, 2018, at 5:25 PM, Bikash Kanungo <bik...@umich.edu> wrote: > > > > Hi, > > > > I'm using the L-BFGS QN solver. In order to set the number of past > states (also the restart size if I use Periodic restart), to say 50, I'm > using PetscOptionsSetValue("-snes_qn_m", "50"). However while running, it > still shows "Stored subspace size: 10", i.e., the default value of 10 is > not overwritten. > > > > Additionally, I would like to know more about the the > -snes_qn_powell_descent option. For Powell restart, one uses a gamma > parameter which I believe is defined by the -snes_qn_powell_gamma option. > What exactly does the descent condition do? It would be useful if there are > good references to it. > > > > Thanks, > > Biksah > > > > -- > > Bikash S. Kanungo > > PhD Student > > Computational Materials Physics Group > > Mechanical Engineering > > University of Michigan > > > > -- 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 https://www.cse.buffalo.edu/~knepley/ <http://www.caam.rice.edu/~mk51/>