How to terminate once gap% is small?

Answered

David Coley

October 02, 2025 08:53

• 
• 

I am solving a large MLP with Gurobi. An accuracy of 0.5% gap in determining the objective function value is sufficient for my purposes. However, Gurobi is taking a long time to go from 0.5% to an exact solution.

Is there a way to terminate model.optimize() and retrieve upper and lower bounds once the gap% reaches a specified threshold?

My output looks like the table below. Once Gap is small, how do I automatically terminate the calculation?

Objective Bounds        
Incumbent    BestBd    Gap
7478.4    1247.71731    83.30%
1280.13    1247.71731    2.53%
1279.8658    1247.71731    2.51%
1264.3452    1247.71731    1.32%
1263.5402    1247.71731    1.25%
1263.4653    1247.71731    1.25%
1263.3875    1247.71731    1.24%
1263.3722    1247.71731    1.24%
1262.1739    1247.71731    1.15%
1262.102    1247.72661    1.14%
 

Related to

• MIP Gap

0

• Official comment

  

  Ronald van der Velden

  • Gurobi Staff

  October 02, 2025 11:30

  Hi David,

  Consider setting the MIPGap parameter to 0.005 before solving. This will tell Gurobi to stop as soon as it finds a gap of 0.5%. You can then access the solution and the ObjVal and ObjBound attributes.

  Kind regards, 
  Ronald
• 

  David Coley

  October 02, 2025 11:38

  • 
  • 

  Thank you. I found the answer I need on this post:

   

  https://support.gurobi.com/hc/en-us/community/posts/15423027654929-Stopping-Criteria-based-on-reduced-gap-per-time

  0

Please sign in to leave a comment.