[Top][All Lists]
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Bug-glpk] [Fwd: preprocessing goes into infinite loop]
From: |
glpk xypron |
Subject: |
Re: [Bug-glpk] [Fwd: preprocessing goes into infinite loop] |
Date: |
Sat, 14 Jan 2012 15:29:18 +0100 |
Hello Andrew,
I suggest that the problem due to missing bounds should be gracefully
detected and a meaningful message should be displayed to the user.
Best regards
Xypron
-------- Original-Nachricht --------
> Datum: Sat, 14 Jan 2012 18:13:14 +0300
> Von: Andrew Makhorin <address@hidden>
> An: glpk xypron <address@hidden>
> CC: address@hidden, John Perry <address@hidden>
> Betreff: Re: [Bug-glpk] [Fwd: preprocessing goes into infinite loop]
> Hi Xypron,
>
> > when running glp_simplex on the problem, I get this output:
> > GLPK Simplex Optimizer, v4.47
> > 45 rows, 5 columns, 123 non-zeros
> > 0: obj = 5.000000000e+00 infeas = 3.750e+01 (0)
> > 37: obj = 1.400000000e+01 infeas = 8.833e+00 (0)
> > PROBLEM HAS NO FEASIBLE SOLUTION
> >
> > I then used John's coding to write the appended file in CPLEX format.
> >
> > glpsol --lp test.lp leads to the following error in the presolver:
> >
> > Preprocessing...
> > Assertion failed: q->lb < q->ub
> > Error detected in file ..\src\glpnpp03.c at line 556
>
> This diagnostics is not relevant due to floating-point overflow (please
> see my recent posting to bug-glpk). The glpk code is not intended to
> work with Inf's and NaN's, so such values completely destroy the program
> logic.
>
> >
> > I would not have expected such an error.
> >
>
>
> Andrew Makhorin
>
--
Follow me at http://twitter.com/#!/xypron
Empfehlen Sie GMX DSL Ihren Freunden und Bekannten und wir
belohnen Sie mit bis zu 50,- Euro! https://freundschaftswerbung.gmx.de