Get Gurobi to use pure cutting plane method for MIP?

Answered

Michael Curry

• July 29, 2019 15:17

I would like to force Gurobi to use a pure cutting plane method to solve a MIP -- no branching. Is there a way to tell Gurobi to do this -- force it to do everything at the root node? (I promise I have good reasons to do this even if it hurts performance.)

The next step would be to actually read out the (hopefully presolved) system along with the newly generated constraints -- is this also possible?

0

• Official comment

  

  Simranjit Kaur

  Gurobi Staff

  • December 06, 2024 00:55

  This post is more than three years old. Some information may not be up to date. For current information, please check the Gurobi Documentation or Knowledge Base. If you need more help, please create a new post in the community forum. Or why not try our AI Gurobot?.
• 

  Tobias Achterberg

  Gurobi Staff

  • July 29, 2019 15:43

  Unfortunately, the answer to both of your questions is "no". You can tell Gurobi to use pretty much all cuts it finds by setting the "CutPasses" parameter to a very large number. But still, Gurobi won't necessarily generate all cuts required to get the convex hull of the integer feasible points. It discards cuts due to numerical reasons, it separates only cuts that are "violated enough", it may not generate all Gomory cuts due to performance reasons, and so on.

  The cuts are generated in terms of the presolved model. Because Gurobi does not allow access to the presolved model, you also cannot extract the cuts that were generated.

   

  Best regards,

  Tobias

  0

Post is closed for comments.