changing default values in options database
griffith at cims.nyu.edu
Fri Nov 7 12:06:21 CST 2008
Hi, Folks --
I'm using some KSP solvers in a preconditioner (using FGMRES as the
"outer" Krylov solver). For these preconditioner KSPs, I generally want
to use relatively loose relative convergence tolerances.
Presently, I check to see if, e.g., -solver1_ksp_rtol,
-solver2_ksp_atol, -solver3_max_it, etc., are set in the options
database. If a particular value is not set in the options database, I
manually set that value to some value which is different from the
default PETSc value. Of course, when I use the `-help' flag, the help
for each of the solvers indicates the default values for rtol, atol,
max_it, etc. are the standard PETSc defaults.
Is there a simple way to change these default values for individual
solvers? In particular, I would like to be able to ensure that the
default values listed by `-help' correspond to the values that I'm
specifying in the code.
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