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

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.


Bikash S. Kanungo
PhD Student
Computational Materials Physics Group
Mechanical Engineering
University of Michigan

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