Opened 9 years ago

Closed 8 weeks ago

#95 closed defect (migrated)

not finding glable optimum with an SOS2 formulation solving using CBC

Reported by: ylee77 Owned by:
Priority: major Component: Cbc
Version: Keywords:
Cc:

Description

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

Attachments (3)

Router_SolverInput_5ee4fe4b-e64b-4912-a036-2ad16dc6ebbc.txt (452 bytes) - added by ylee77 9 years ago.
data set
NonconvexPLOptimization.pdf (135.0 KB) - added by ylee77 9 years ago.
formulation
OptimizeSimple.cpp (21.8 KB) - added by ylee77 9 years ago.
see function of "PfofModel_OptimizeMaxParticipation"

Download all attachments as: .zip

Change History (5)

Changed 9 years ago by ylee77

formulation

Changed 9 years ago by ylee77

see function of "PfofModel_OptimizeMaxParticipation"

comment:1 Changed 9 years ago by ylee77

And by the way, isProvenOptimal() returns 0 yet status() and secondaryStatus() both return 0 (search completed).

comment:2 Changed 8 weeks ago by stefan

  • Component set to Cbc
  • Resolution set to migrated
  • Status changed from new to closed

This ticket has been migrated to GitHub and will be resolved there: https://github.com/coin-or/Cbc/issues/95

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