[Scip] Segmentation Fault
Julio Rojas
jcredberry at gmail.com
Thu Nov 19 12:11:39 MET 2009
I'm running a series of simulations and it seems that this binary is ok. No
segfaults yet.
Is it possible that you add a way for the standalone solver to keep sunning
after finding the first solution? I mean, if I would like to keep looking
for more solutions I would issue a command like "nextsol" and the solver
would run again to find the next solution.
Thank you very much.
-------------------------------------------------
Julio Rojas
jcredberry at gmail.com
On Thu, Nov 19, 2009 at 11:46 AM, Stefan Vigerske
<stefan at math.hu-berlin.de>wrote:
> Hi,
>
> try the binary from
> http://www.math.hu-berlin.de/~stefan/scip-1.2.0.linux.x86.gnu.opt.clp<http://www.math.hu-berlin.de/%7Estefan/scip-1.2.0.linux.x86.gnu.opt.clp>
> It is a patched version of SCIP 1.2.0 linked against CLP 1.11 and Ipopt
> 3.7.
>
> Best,
> Stefan
>
> Am 19.11.2009 11:30, schrieb Julio Rojas:
> > I downloaded the binary for Linux32. Again thanks.
> > -------------------------------------------------
> > Julio Rojas
> > jcredberry at gmail.com
> >
> >
> > On Thu, Nov 19, 2009 at 11:29 AM, Stefan Vigerske
> > <stefan at math.hu-berlin.de>wrote:
> >
> >> Hi,
> >>
> >> did you compile SCIP with CLP from source or you downloaded a binary?
> >>
> >> If you got it from source, go into the scip-1.2.0 directory and do
> >> patch -p1 < scip.patch
> >> Then recompile.
> >> Or you can look at scip.patch and change things in the souce by hand.
> >> Important are those in lpi_clp.cpp and heur_trivial.c.
> >>
> >> If you downloaded a binary, then for which platform?
> >>
> >> Stefan
> >>
> >>
> >> Am 19.11.2009 11:21, schrieb Julio Rojas:
> >>> Thanks for the patch, but how can I apply it?
> >>> -------------------------------------------------
> >>> Julio Rojas
> >>> jcredberry at gmail.com
> >>>
> >>>
> >>> On Thu, Nov 19, 2009 at 11:16 AM, Stefan Vigerske
> >>> <stefan at math.hu-berlin.de>wrote:
> >>>
> >>>> Hi,
> >>>>
> >>>> there is a bug in the SCIP/CLP interface.
> >>>> The patch is attached.
> >>>>
> >>>> Stefan
> >>>>
> >>>> Am 19.11.2009 10:04, schrieb Julio Rojas:
> >>>>> Dear all, I have been using SCIP-CLP to solve some BIP problems of my
> >> PhD
> >>>>> work. One of the problems has the generic form:
> >>>>>
> >>>>> Min Sum(Xi)
> >>>>> s.t.
> >>>>> Xi+Xk <= 1, if Aik=1 and i<k, for i,k in {1,...,n}
> >>>>> Xi-Xk = 0, if {Xi,Xk} in Pj for all j in {1,...,g}, g<n
> >>>>> Sum(Xi)>=floor(n/2)+1
> >>>>> Xi in {0,1}
> >>>>>
> >>>>> I know that for some setups this problem is unfeasible, but sometimes
> I
> >>>> get
> >>>>> segmentation fault errors like in the attached example.
> >>>>>
> >>>>> I use the standalone solver. After loading it the message presented
> is
> >>>> the
> >>>>> following:
> >>>>>
> >>>>> original problem has 75 variables (0 bin, 75 int, 0 impl, 0 cont) and
> >> 846
> >>>>> constraints
> >>>>>
> >>>>> After presolve, the message is:
> >>>>>
> >>>>> presolving:
> >>>>> (round 1) 69 del vars, 690 del conss, 0 chg bounds, 0 chg sides, 0
> chg
> >>>>> coeffs, 0 upgd conss, 1046 impls, 0 clqs
> >>>>> (round 2) 69 del vars, 842 del conss, 0 chg bounds, 0 chg sides, 0
> chg
> >>>>> coeffs, 0 upgd conss, 1046 impls, 0 clqs
> >>>>> (round 3) 69 del vars, 842 del conss, 0 chg bounds, 0 chg sides, 0
> chg
> >>>>> coeffs, 3 upgd conss, 1046 impls, 0 clqs
> >>>>> (round 4) 69 del vars, 842 del conss, 0 chg bounds, 0 chg sides, 0
> chg
> >>>>> coeffs, 4 upgd conss, 1046 impls, 0 clqs
> >>>>> (round 5) 70 del vars, 842 del conss, 0 chg bounds, 2 chg sides, 4
> chg
> >>>>> coeffs, 4 upgd conss, 1056 impls, 0 clqs
> >>>>> (round 6) 71 del vars, 843 del conss, 0 chg bounds, 3 chg sides, 6
> chg
> >>>>> coeffs, 4 upgd conss, 1060 impls, 0 clqs
> >>>>> (round 7) 71 del vars, 846 del conss, 1 chg bounds, 5 chg sides, 8
> chg
> >>>>> coeffs, 4 upgd conss, 1062 impls, 0 clqs
> >>>>> (round 8) 72 del vars, 846 del conss, 1 chg bounds, 5 chg sides, 8
> chg
> >>>>> coeffs, 4 upgd conss, 1062 impls, 0 clqs
> >>>>> presolving (9 rounds):
> >>>>> 72 deleted vars, 846 deleted constraints, 1 tightened bounds, 0
> added
> >>>>> holes, 5 changed sides, 8 changed coefficients
> >>>>> 1062 implications, 0 cliques
> >>>>> presolved problem has 3 variables (3 bin, 0 int, 0 impl, 0 cont) and
> 3
> >>>>> constraints
> >>>>> 1 constraints of type <knapsack>
> >>>>> 2 constraints of type <logicor>
> >>>>> Presolving Time: 0.01
> >>>>>
> >>>>> So, as you can see, the problem should be unfeasible, but when I run
> >> the
> >>>>> solving routine I get the following message:
> >>>>>
> >>>>> time | node | left |LP iter| mem |mdpt |frac |vars |cons
> |ccons|cols
> >>>>> |rows |cuts |confs|strbr| dualbound | primalbound | gap
> >>>>> t 0.0s| 1 | 0 | 0 | 449k| 0 | - | 3 | 3 | 3 |
> 0
> >> |
> >>>>> 0 | 0 | 0 | 0 | -- | 1.192662e+03 | Inf
> >>>>> t 0.0s| 1 | 0 | 0 | 449k| 0 | - | 3 | 3 | 3 |
> 0
> >> |
> >>>>> 0 | 0 | 0 | 0 | -- | 1.170286e+03 | Inf
> >>>>> Segmentation fault
> >>>>>
> >>>>> Any idea on what's happening? Is there a way to avoid this problem?
> I'm
> >>>>> running the standalone solver from an R script, so I don't know if by
> >>>> using
> >>>>> C I can catch this problem. I don't program in C. Can I trust that
> when
> >>>> this
> >>>>> happens the solution is unfeasible? I can cope with this problem if
> it
> >> is
> >>>>> presented when the solution is unfeasible and some set of features
> >> exist
> >>>> in
> >>>>> the model.
> >>>>>
> >>>>> Thank you very much for your help.
> >>>>> -------------------------------------------------
> >>>>> Julio Rojas
> >>>>> jcredberry at gmail.com
> >>>>>
> >>>>>
> >>>>>
> >>>>>
> >>>>> _______________________________________________
> >>>>> Scip mailing list
> >>>>> Scip at zib.de
> >>>>> http://listserv.zib.de/mailman/listinfo/scip
> >>>>
> >>>>
> >>>
> >>
> >>
> >
>
>
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