[Cbc-tickets] [COIN-OR Branch-and-Cut MIP Solver] #95: not finding glable optimum with an SOS2 formulation solving using CBC

[COIN-OR Branch-and-Cut MIP Solver]

#95: not finding glable optimum with an SOS2 formulation solving using CBC
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Reporter:  ylee77  |       Type:  defect
  Status:  new     |   Priority:  major 
 Version:          |   Keywords:        
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 Hello,

 I am confronting a problem that the solution obtained from CBC doesn't
 coincide with what I obtained from CPLEX. I actually tried two ways to
 code up the SOS2 formulation and they both return same values, with a
 claim that the search is complete and the solution is proven optimum. Yet
 I can see the solution is not optimum and is different from what CPLEX
 get. I wonder whether there is some internal problem inside the branch-
 and-bound. Thanks a lot.

 Attached is
 1. the problem formulation
 2. the input data set
 3. a piece of code that includes the function "
 PfofModel_OptimizeMaxParticipation" which I coded the SOS2 formulation and
 using branch and bound to solve it.


 Sincerely,
 Yu-Ching

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Ticket URL: <https://projects.coin-or.org/Cbc/ticket/95>
COIN-OR Branch-and-Cut MIP Solver <http://projects.coin-or.org/Cbc>
An LP-based branch-and-cut MIP solver.