Decision variable indices as a tuple or a list

Answered

Maide Ceren Kaymaz

April 10, 2023 16:29

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Hello, how can I set an indices as a tuple or a list for a continuous variable in a constraint (in Python)?
Here Pr,l demonstrates a list with 2 dimensions

 

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• Official comment

  

  Simranjit Kaur

  • Gurobi Staff

  November 13, 2026 01:45

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  Matthias Miltenberger

  • Gurobi Staff

  April 12, 2023 17:08

  Hi Maide,

  You can pass multiple lists as indices to Model.addVars(). I suggest you try this with a smaller list to understand how the indexing works.

  I hope that answers your question.

  Cheers,
  Matthias

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  Maide Ceren Kaymaz

  April 14, 2023 21:27 Edited

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  Hi Matthias, Matthias Miltenberger thank you for your answer. Is there a way to set tuple indices while adding in a constraint instead of defining as a variable? I'd like to define this variable as Zm,r,t,i but I'd like to use it as Zm,r,t,p(r,l) in the constraint like in the picture above.
  
  Best,
  Maide

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  Matthias Miltenberger

  • Gurobi Staff

  April 18, 2023 11:40

  Hi Maide,

  You can restrict the use of your variables in a conditional sense, by just querying your condition while formulating the constraint:

  addConstrs(x[i] + y[k] = 1 for i in I for k in K if i==k)

  Is this what you're after? Please consider that you cannot rely on (partly) solutions to your problem when formulating the model because this information will only be available after the solving process.

  Cheers,
  Matthias

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