[Dip-tickets] [Dip] #72: Root bound anomaly

[Dip]

#72: Root bound anomaly
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  Reporter:  vejlin  |      Owner:       
      Type:  defect  |     Status:  new  
  Priority:  major   |    Version:  trunk
Resolution:          |   Keywords:       
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Comment (by mgalati):

 A side note.

 * The PC bound with MasterGapLimit=0 is -181.24.
 * The CPM bound with MasterGapLimit=0 is -177.07.

 This is an interesting case. Theoretically, if CPM and PC use the same
 outer approximation (the cuts), then the PC root bound should not be worse
 than the CPM bound. In this case, you are using the default CGL cuts.
 However, since we don't know how to generate gomory cuts in the PC context
 - they are disabled for PC and this can make the PC bound weaker than the
 CPM bound. You can see in the CPM log that gomory cuts are generated which
 help in this case.

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Ticket URL: <https://projects.coin-or.org/Dip/ticket/72#comment:5>
Dip <https://projects.coin-or.org/Dip>
An extensible software framework for implementing decompositon-based bounding algorithms for use in solving large-scale discrete optimization problems.