[Coin-lpsolver] Segmentation faults

[John J Forrest]

David,

At first glance it all looks plausible.

If you just use one cut generator does that seg fault?

One thing you could do is 

model.solver()->writeMps(filename) 

before going into branch and bound and then use that mps file as input to 
e.g. sample2.cpp and see if that solves okay.  Obviously the cut 
generators should not fail so there may be something odd about your data.

If mps file fails then send it to me and I will see if I can reproduce.

John Forrest



svoboda at fi.muni.cz 
Sent by: coin-lpsolver-bounces at list.coin-or.org
03/01/2005 09:59 AM

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[Coin-lpsolver] Segmentation faults






Hello,

I'm a beginner in using COIN-Cbc. I have to admit, that I know linear 
programming techniques whereas integer programming (the cuts etc.) is more 

difficult for me. I used some sample?.cpp files from Cbc to experiment 
with my data. Everything worked OK until I tested CutGenerators. Namely 
CglProbing, CglGomory and CglOddHole which cause "segmentation fault" in 
my programs. I do not know how to set the right options for these 
generators to avoid the mentioned problems. I do not know the meaning for 
"set" methods - therefore I do not know how to set the right values.

Here is the part of the code, I'd like to set properly:

   CglProbing probingGen;
   probingGen.setUsingObjective (true);
   probingGen.setMaxPass (3);
   probingGen.setMaxProbe (100);
   probingGen.setMaxLook (numberOfCols);
   probingGen.setRowCuts (3);

   CglGomory gomoryGen;
   gomoryGen.setLimit (numberOfCols);

   CglOddHole oddholeGen;
   oddholeGen.setMinimumViolation (0.005);
   oddholeGen.setMinimumViolationPer (0.00002);
   oddholeGen.setMaximumEntries (numberOfCols);

  model.addCutGenerator (&probingGen, -1, "Probing");
  model.addCutGenerator (&gomoryGen, -1, "Gomory");
  model.addCutGenerator (&oddholeGen, -1, "OddHole");


As for my integer linear programming problem, there are:
- M rows
- N columns
- the values of individual variables are all set to "0" or "1"


With regards

  David
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