KINSOL exits prematurely on simple nonlinear problem
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- Dominant language
- C++
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Description
here's a sourcefile with a reproducer:
[beam_bending.zip](https://github.com/LLNL/serac/files/11578278/beam_bending.zip)
When running this problem with the Kinsol Newton option, it performs a few iterations and exits with the error message:
```
[KINSOL] KINSol
Return value: -7 (KIN_MXNEWT_5X_EXCEEDED)
[KINSOL ERROR] KINSol
Five consecutive steps have been taken that satisfy a scaled step length test.
```
Using the naive Newton method converges monotonically in ~10 steps. It's unclear to me if this is indicative of a bug in our wrapper of Kinsol or if we just need to adjust some knobs.
Contributor guide
First steps
- Read the whole issue, then the project's contributing guide.
- Comment on the issue to say you are picking it up — it saves two people doing the same work.
- Fork the repository and make your change on a branch.
- Open a pull request that references the issue number.
Research direction
Start by unpacking and running the attached beam_bending.zip reproducer with the KINSOL Newton option, then compare its behavior with the naive Newton method. Trace the KINSOL wrapper and configuration involved; done means determining whether the premature KIN_MXNEWT_5X_EXCEEDED exit is a wrapper bug or requires documented solver settings.
Written by the indexing model from the issue text.
Assessment
- Tech stack
- cpp
- Domain
- hpc
- Issue type
- Bug
- Difficulty
- 4/5
- Estimated time
- 3-5 days
- Activity status
- Stale
- Clarity
- Needs clarification
- Newbie friendliness
- 30/100