Wrong root node number

Answered

Jiajie Zhang

May 27, 2022 12:32

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Hi, I want to add cuts at root nodes. I first locate them by MIPNODE_NODCNT, but the node number is 5005. I am confused. Below are my codes.

if where == MIPNODE:

    cnt = GRB.Callback.MIPNODE_NODCNT

print(cnt)

The result is 5005.

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• Official comment

  

  Simranjit Kaur

  • Gurobi Staff

  November 16, 2025 23:36

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  David Torres Sanchez

  • Gurobi Staff

  May 27, 2022 14:36 Edited

  Hi Jiajie,
  
  \( \texttt{GRB.Callback.MIP_NODCNT} \) is just a constant (with value 5005).
  The correct way to query this attribute is:

  nodecnt = model.cbGet(GRB.Callback.MIP_NODCNT)

  Please see the Python callback example for more details.

  Cheers, 
  David

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  Jiajie Zhang

  May 28, 2022 02:33

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  Thank you very much David. That exactly what I want.

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