Debugging Model

回答済み

Shesha Sreenivasamurthy

• 2024年10月11日 04:24

The model that have is fairly complex and it becomes infeasible when I add a constraint. However, logically that constraint should hold good. How can I debug it. It was suggested to use model.computeIIS(). However, I am not sure how to interpret it. Where can I find information about debugging techniques that i can use?

関連するエンティティ

• Infeasible
• computeIIS

0

• 

  Ryuta Tamura

  Gurobi Staff

  • 2024年10月11日 06:38
  • 編集済み

  Hi Shesha,

  These articles may help: How do I diagnose a wrong result?, Why does Gurobi report my model is infeasible when it has a feasible solution?.

  The model.computeIIS() finds the set of the constraints that are the cause of infeasibility. That can be written as "ilp" file for debugging.

  model.optimize()
  if model.Status == GRB.INFEASIBLE:
      model.computeIIS()
      model.write("IIS.ilp")

  Debugging can be difficult when there is a large amount of data or when the model is complex. So I recommend to start with a small data set/simple model to identify factors that may lead infeasibility.

  Thanks,
  Ryuta

  0

サインインしてコメントを残してください。