[Bonmin] boncouenne crash

[Pietro Belotti]

Dear Francois,

the problem seems to be with an integer feasible solution that 
becomes infeasible after the variable's bounds are tightened by a 
procedure in the LP solver interface. The latest revision has a 
temporary fix that skips that tightening procedure, at least until 
we find a workaround.

Let me remind you that Couenne is still an experimental project, 
so it is preferable, at least for the time being, to use more 
stable code such as the nonconvex heuristics in Bonmin.

Best regards,
Pietro Belotti

----------------------------------------
Pietro Belotti, Postdoctoral Fellow
Tepper School of Business
Carnegie Mellon University
email: belotti at andrew.cmu.edu
phone: +1 (412) 268-5974
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> Dear mailing list,
>
> I just got an error message when I try to solve a nonconvex 
> MINLP problem using boncouenne from within an AMPL script.
>
> There are four files attached to this message:
> mymodel.mod is the AMPL model,
> tmp.dat is the data file,
> myscript.txt is the AMPL script,
> log.txt is the captured output of AMPL when it calls boncouenne .
>
> The script is called with:
> ampl myscript.txt
> ,which sets boncouenne as the solver, then the model and data 
> files are loaded before solving.
>
> I'm using boncouenne downloaded by SVN from trunk on 11 august 
> 2008. My OS is Ubuntu Linux Hardy Heron.
>
> Your advice will be appreciated.