bug-glpk
[Top][All Lists]
Advanced

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Bug-glpk] Some unsuccessful runs (Windows, 4.55, 4.56, 4.59, 4.59.2


From: Andrew Makhorin
Subject: Re: [Bug-glpk] Some unsuccessful runs (Windows, 4.55, 4.56, 4.59, 4.59.2)
Date: Sun, 27 Mar 2016 19:29:17 +0300

Anton,

> There are ten inputs originally collected for GLPK 4.55.
> Three of them do not confuse GLPK since 4.56, at least for one
> hour horizon. Another two invariably force the solver to fail.
> 
> >From 4.55, 4.56 to 4.59, 4.59.2, the set of errors has changed.
> Now it includes, besides locking in dual simplex,
>    Assertion failed: tcol[csa->p] != 0.0
>    Error detected in file ..\src\simplex\spydual.c at line ...
> and
>    glp_intopt: cannot solve current LP relaxation.
> 

Thank you very much for your evaluation of glpk. Your models have some
unusual numerical properties that helps me to reveal some rare cases in
the simplex algorithms.

I added another feature to the glpk dual simplex solver, which is the
perturbation of objective coefficients used to avoid numerical
instability and cycling.

I will inform you about a new release of glpk.


Best regards,

Andrew Makhorin





reply via email to

[Prev in Thread] Current Thread [Next in Thread]