[Couenne-tickets] [Couenne] #33: Counne says "tightened NLP is infeasible"

[Couenne]

#33: Counne says "tightened NLP is infeasible"
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  Reporter:  thofrei  |      Owner:  pbelotti
      Type:  defect   |     Status:  new
  Priority:  major    |  Milestone:
 Component:  Couenne  |    Version:
Resolution:           |   Keywords:  infeasible Couenne tightened NLP
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Comment (by pbelotti):

 Hi,

 it seems there is a bug in strong branching that reports an infeasible
 problem. Turning off strong branching seems to allow Couenne to continue,
 though the problem is quite large and I could not find a solution for a
 few hours. I'll try to fix this, but in the meantime you can try the
 following options:

 {{{
 feasibility_bt  yes
 redcost_bt      yes
 aggressive_fbbt yes
 optimality_bt   yes

 iterative_rounding_heuristic yes

 output_level 2

 bb_log_level 1
 nlp_log_level 0
 lp_log_level 0

 log_num_obbt_per_level 1
 log_num_abt_per_level 1
 log_num_local_optimization_per_level 10

 branching_object var_obj
 variable_selection osi-simple
 }}}

 The last line is to turn off strong branching, while the rest is to
 increase the frequency of heuristics. Being a large problem, though,
 finding a solution won't be easy.

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Ticket URL: <https://projects.coin-or.org/Couenne/ticket/33#comment:7>
Couenne <https://projects.coin-or.org/Couenne>
Couenne, a solver for non-convex MINLP