[petsc-users] -ts_adapt_clip .5,1.25

[Jed Brown]

See -ts_adapt_scale_solve_failed.  The clip provides bounds on step
shortening as a result of the error indicator, but a solve failing can
be more severe.  The default clip allows more aggressive shortening, but
I don't think we want clip to be a lower bound on solver-failure
shortening.  And if you shorten and still fail, you want to be able to
shorten more.

Mark Adams <mfadams at lbl.gov> writes:

> I use -ts_adapt_clip .5,1.25, with -ts_type arkimex -ts_arkimex_type 1bee.
> When SNES hits max_it (in the first stage), TS seems to reduce the time
> step by 4x. I don't see where that 4x comes from and how to adjust it. Is
> it in the "safety" stuff?
> Thanks,
> Mark