On Wed, Nov 1, 2017 at 8:30 PM, Jed Brown <[email protected]> wrote: > Mark Adams <[email protected]> writes: > > >> > >> > >> > >> The last relevant output you've shown me is SNES failing a bunch of > >> times as the adaptive controller attempts to shrink the step size and > >> retry. If you fixed that problem, you need to tell me. If not, THAT is > >> the problem you need to fix. > >> > > > > That is the problem I am trying to fix. > > The solution to that isn't on the outside. >
Does the "inside" exist or is there simply not a proof that it does not exist? > > > Note, I am also adapting the time step when the solver converges but > > talks a lot of iterations. Thus, no need for recovery. > > You can encapsulate that in an adaptive controller or put the logic (to > get the SNES iteration number and decided whether to TSSetTimeStep) in > the TS PostStep function. > That is what I do, and it is fine. It works well enough, I now am trying to deal with TS failure. > > > It is the SNES failure, recover, cut time step, try again, that I am > > working in now. > > That is already running in the TSAdapt. Your failure is a result of > something else. Use -ts_adapt_monitor for more diagnostics about the > controller's decisions. > I looked at TSAdapt for the first problem, of adapting when this look bad but work. It failed because its algo was not quite right for this problem. So I put a simple algo in a post step method. Can TSAdapt deal with a SNES failure, recover, cut time step, and rerun the step? > > > > >> > >> Did you read about -ts_error_if_step_fails on the man page > > > > > > Google, and found the command line args > > > > > >> for the > >> functional interface I just cited? > >> > >> > > Sorry, I missed this cite and used 'git grep' to see that it was there > > (Matt sent me the SNES version today so I knew what to look for). > > > > > >> >> but all the logic you're talking about is already in TS and > >> >> jury-rigging it on the outside is counterproductive. So get back to > >> >> the root of the problem and debug why SNES is failing. > >> >> > >> >
