[Couenne] Infeasibility problems with couenne

[Jan Stampfli]

Dear all,

I have some troubles getting feasible solutions for my MINLP formulation using couenne. My model is basically a NLP model but I have to use some binary variables for selecting values. Thereby, the binary variables are declared as integer with bounds 0 and 1 instead binary. I wrote my model in pyomo 5.3 (python 2.7) and using couenne 0.5.  To get feasible solutions, I changed the options as follows:


  *   lp_log_level 0
  *   bb_log_level 1
  *   nlp_log_level 1
  *   redcost_bt no
  *   optimality_bt no
  *   aggressive_fbbt no
  *   feas_tolerance 1e-4

I do not really understand the output, but I think the cbc does not really proceed to a lower  depth of the BB. In the appendix I have the output of the solver and my couenne.opt. When anyone needs my model please don't hesitate to ask.

Thanks
Jan

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