How to improve LP formulation using presolve

Barak Gross

• August 05, 2020 12:39
• Edited

I have written an Integer Program using the Gurobi Python API and noticed the following row in the log:

Presolve removed 9331080 rows and 2671 columns - which took about 35 seconds.

I know for sure that I won't be able to change my formulation resulting in 0 presolve time, but I want to reduce it, and I feel that in my case it is possible.
From what I see a *lot* of rows are deleted (almost 9.5M), is there a way to check what rows/columns are removed? I suspect that this will help me identify redundant inequalities.

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  Sonja Mars

  Gurobi Staff

  • August 06, 2020 08:21

  Hi Barak,

  How many rows and columns does the original model have? Can you post the corresponding log line?

  Thanks,

    Sonja

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