How to give a parameter list to Gurobi

Answered

Fikri Kucuksayacigil

• January 19, 2022 18:08
• Edited

Hi all,

I use Gurobi to solve an optimization problem in Julia. I might need to try different Gurobi parameters.

Currently, I write parameters and their values inside the model directly, like

Expansion_Model = Model(optimizer_with_attributes(Gurobi.Optimizer, "MIPGap" => 0.01, "TimeLimit" => 91800, "Method" => 2))

I do not want to do this inside the model. Instead, I want to create a list of parameters and add this to the model with a for loop, or with something similar. For instance, by using the same example above,

paramname = ["MIPGap", "TimeLimit", "Method"]

paramvalue = [0,01, 91800, 2]

Expansion_Model = Model(optimizer_with_attributes(Gurobi.Optimizer, paramname => paramvalue))

Or, something like

Expansion_Model = Model(optimizer_with_attributes(Gurobi.Optimizer))

for (x,y) in zip(paramname, paramvalue)

     Expansion_Model.params.add(x,y)

end

In the above example, I just fabricate params and add functions. I am not sure if we have something similar in Julia. Do we have such a flexibilty in Julia?

Thank you

0

• 

  Fikri Kucuksayacigil

  • January 19, 2022 19:00
  • Edited

  

  

  

  Okay, I found the solution. The following works for me:

  paramname  = ["MIPGap", "TimeLimit", "Method"]
  
  paramvalue = [0,01, 91800, 2]
  
  Expansion_Model = Model(optimizer_with_attributes(Gurobi.Optimizer))
  
  for (x,y) in zip(paramname, paramvalue)
  
       set_optimizer_attribute(Expansion_Model, x, y)
  
  end

  0

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