prune nodes in B&B

Answered

Leandro Coelho

July 08, 2020 18:20

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Hello,

 

I have a minimization MIP for which I can infer lower bounds as time goes by. 

Sometimes, my lower bound is better than the solution of a given node. Is there a way to prune the node? I could not find a prune method in the documentation.

Alternatively, I could add a constraint making that particular node infeasible, but I don't seem to find how to add a cut locally in my callbacks. It seems all cuts must be globally valid. 

Any insights about how I could speed up the process?

One raw idea would be to have a branch callback in which I let GRB choose the branching, but I inspect to determine whether to continue or forbid it and make GRB choose another one?

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• Official comment

  

  Simranjit Kaur

  • Gurobi Staff

  June 23, 2025 03:10 Edited

  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?.
• 

  Matthias Miltenberger

  • Gurobi Staff

  July 13, 2020 11:19

  Hi Leandro,

  I saw that you started a small Twitter discussion around this topic, so I'd like to link this here:

  https://twitter.com/leandro_cc/status/1248436643461283840

  Cheers,
  Matthias

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