Print all objective function value?

Answered

Tanmoy Das

• February 08, 2023 05:47

Hello, 

model.objval prints only the optimal objective value. But, I need values of objective function for both optimal (and non-optimal) solutions. 

 

 

Related to

• Solution Pools

1

• 

  Jaromił Najman

  Gurobi Staff

  • February 08, 2023 08:34
  • Edited

  Hi Tanmoy,

  Please refer to the documentation of the Solution Pool and the poolsearch example. Additionally you might want to have a look at the Knowledge Base article How do I find additional solution to a model?

  Best regards, 
  Jaromił

  1
• 

  Tanmoy Das

  • February 08, 2023 14:32
  • Edited

  

  

  

  Hello Jaromil, 

  By allowing larger gap (GRB.Param.PoolGap), I retrieved 36 solution counts based on documentation link you provided:

  Solution count 36: 1.6 1.4 1.3 ... 0.2

  Now I want to print each X & ObjVal for all these 36 solutions. I believe Xn, ObjNVal can help me. But, I cant find how to set the value of k (k dictates whether Xn = X1, X2,..., X36).

   

  0
• 

  Tanmoy Das

  • February 08, 2023 14:56
  • Edited

  

  

  

  The solution to my previous comment is below (for future reference): 

  print('Print Xn')
  k = 34
  model2.setParam(GRB.Param.SolutionNumber, k)
  [x[s, r].Xn for s in Stations for r in ResourcesD]
  [y[s, o, r].Xn for s in Stations for o in OilSpills for r in ResourcesD]
  model.PoolObjVal 

  0

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