It shouldn't have any affect. This will need to be debugged. There's no chance I'll have time for at least a week; hopefully one of the other TS contributors can look sooner.
"Ellen M. Price via petsc-users" <[email protected]> writes: > Quick update: I found that changing TS_EXACTFINALTIME_INTERPOLATE to > TS_EXACTFINALTIME_MATCHSTEP fixes the problem; is there a reason I can't > use the interpolation when using a DMCOMPOSITE? > > Ellen Price > > > On 2/20/19 1:42 PM, Ellen Price wrote: >> Hi fellow PETSc users! >> >> I am attempting to use a DMCOMPOSITE alongside TS and have run into some >> trouble. I'm attaching a MWE demonstrating the problem. The goal is to >> combine a DMDA3d for spatial data and a DMREDUNDANT for non-spatial, >> time-dependent fields. In the attached example, this additional field is >> temperature. >> >> The DMDA data is currently just temperature-dependent, and the >> temperature is supposed to increase linearly. Unfortunately, no matter >> how I integrate (explicitly, using Euler or RK, or implicitly, using >> backward Euler or BDF), I get the wrong final temperature. The >> integration proceeds for 100 timesteps and then stops (verified by >> -ts_monitor). At a heating rate of 1, and an initial temperature of 150, >> I should get a final temperature of 250 very easily. However, I get >> something closer to 200 (not exact, which makes me think this isn't a >> simple missing-a-factor-of-2 error). >> >> I'm currently using TSSetDM with the composite DM to let PETSc compute >> the Jacobian. Having checked all the inputs and outputs as well as I >> can, this is the only step that seems like it may be causing a problem; >> yet even explicit integration doesn't work, and that shouldn't need the >> Jacobian at all. I'm at a loss. >> >> Run using: >> ./mwe -implicit yes -ts_type beuler -ts_monitor OR ./mwe -implicit no >> -ts_type euler -ts_monitor >> >> Thanks in advance for any help, >> Ellen Price
