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How does gurobi calculate the "Node Depth" number shown in logs?

Answered
Nicolas Zerega
Edited
  • Gurobi-versary
  • Curious
  • Conversationalist

Hi everyone, as the title says, I'm curious as how does gurobi get that number. Since, to the best of my knowledge (and this post https://support.gurobi.com/hc/en-us/community/posts/360047974992-Get-current-BnB-node-depth?input_string=How%20does%20gurobi%20calculate%20the%20%22Node%20Depth%22%20number%20shown%20in%20logs%3F) there's no way to access node depth.

I need this number so I can stop adding cuts when a certain depth is reached.

It would be very appreciated if someone has created a way to get this number and is able to share it (i'm working with python but i don't think that matters very much)

Regards,

Nicolas

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Comments

4 comments

Date Votes
  • Official comment
    Simranjit Kaur
    • Gurobi Staff
    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 try Gurobot, our chatbot interface offering instant, expert-level support.
  • Jaromił Najman
    • Gurobi Staff
    Edited

    Hi Nicolas,

    Unfortunately, it is not possible to access the node depth value in Gurobi. The node depth reported in modern Branch-and-Bound algorithms used in today's solvers often does not necessarily reflect the traditional definition of node depth (I cannot go into more detail here). The reported node depth is mainly an artifact from "simpler" times.

    Our team experimented with cuts based on a given node depth in the past and came to the conclusion that it is not very promising. Using the dual and/or primal bound turned out to be way more effective when thinking about stopping/starting to generate cuts.

    Best regards, 
    Jaromił

    0
  • Nicolas Zerega
    • Gurobi-versary
    • Curious
    • Conversationalist

    Hi Jaromil,

    Thanks you very much for answering. I will try to play around with dual and primal bounds and see what happens. So, if I understand correctly, I shouldn't consider the "node depth" number at face value, right?

     

    Again, thanks for the answer!

    Regards,

    Nicolás

    0
  • Jaromił Najman
    • Gurobi Staff

    HI Nicolás,

    So, if I understand correctly, I shouldn't consider the "node depth" number at face value, right?

    Correct.

    Best regards, 
    Jaromił

    1

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