[Dip-tickets] [Dip] #38: Error: CBC IP solver 2nd status = 7

[Dip]

#38: Error: CBC IP solver 2nd status = 7
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Reporter:  kmartin  |       Type:  defect
  Status:  new      |   Priority:  minor 
 Version:  trunk    |   Keywords:        
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 I am experimenting with Dip and solving a simple plant location problem.
 In my approach, there is a block (relaxed constraint set) for each plant.
 There is a relaxed constraint set for each i (plant)  and the relaxed
 constraints for block i are:

 x_{ij} \le y_{i}  for all j

 In this case the y_{i} is a binary variable so the sub-problem is bounded.
 However I get the error

 Error: CBC IP solver 2nd status = 7
 COIN Exception [ CBC solver 2nd status ] at
 ../../../Dip/src/DecompModel.cpp:L330 in DecompAlgoModel::solveOsiAsIp

 If I add upper bounds of 1 on the x_{ij} variables it works and runs to
 completion with the correct optimal solution. However, it seems like I
 should not have to do this since the constraints x_{ij} \le y_{i} with
 y_{i} having an upper bound imply this.

 Thanks

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Ticket URL: <https://projects.coin-or.org/Dip/ticket/38>
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.