[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,

 Reformulation actually takes a short time. However, the problem is quite
 large and Couenne can't explore many BB nodes. Below is the output with
 stable/0.4. Strong branching indeed seems to slow it down a bit.

 {{{
 Couenne 0.4 --  an Open-Source solver for Mixed Integer Nonlinear
 Optimization
 Mailing list: couenne at list.coin-or.org
 Instructions: http://www.coin-or.org/Couenne

 Reformulating problem: 0.2 seconds
 Loaded instance "IT_Model.nl"
 Constraints:         1066
 Variables:           1074 (0 integer)
 Auxiliaries:          273 (77 integer)

 NLP Heuristic: Probing: 39 improved bounds
 NLP Heuristic: Cbc0031I 59 added rows had average density of 2.7627119
 Cbc0013I At root node, 59 cuts changed objective from 3.8639469 to
 3.8639469 in 10 passes
 Cbc0014I Cut generator 0 (Couenne convexifier cuts) - 415 row cuts average
 2.7 elements, 1 column cuts (60 active)
 Cbc0010I After 0 nodes, 0 on tree, 1e+50 best solution, best possible
 3.8639469 (38.89 seconds)
 [...]
 }}}

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Ticket URL: <https://projects.coin-or.org/Couenne/ticket/33#comment:12>
Couenne <https://projects.coin-or.org/Couenne>
Couenne, a solver for non-convex MINLP