Taking remainders in gurobi

Answered

Shesha Sreenivasamurthy

October 10, 2024 07:23 Edited

• 
• 
• 

Hi, I was interested in taking remainder in Gurobi and I referenced the following post.

https://support.gurobi.com/hc/en-us/community/posts/5878990407185-How-to-take-the-remainder-of-the-variables-in-gurobi

However, I am facing an issue.

I want to perform T % 32. Say T is 320 and I expect the remainder to be 0. To formulate this, I have 320 = 32 * a + b. Gurobi gave result a = 9, b = 32. How to ensure that 'b' gets the minimum value. So, 'a' should be 10 and 'b' is zero.

0

• Official comment

  

  Simranjit Kaur

  • Gurobi Staff

  November 13, 2026 01:13 Edited

  This post is more than two years old. Some information may not be up to date. For current information, please check the Gurobi Documentation or Knowledge Base. If you need more help, please create a new post in the community forum, or try Gurobot, our chatbot interface offering instant, expert-level support.
• 

  Shesha Sreenivasamurthy

  October 10, 2024 07:26

  • 
  • 
  • 

  I think I found the answer, I set upper bound for b to be 31. Let me know if this not the right way.

  0
• 

  Matthias Miltenberger

  • Gurobi Staff

  October 10, 2024 09:37 Edited

  Hi Shesha,

  a=9 and b=32 is a perfectly valid solution to the problem. To enforce that Gurobi selects a solution that minimizes the remainder b, you need to specify exactly that and add b to your objective function.

  Setting the upper bound of the remainder to be n-1 for n being the modulo value, is also a good idea nonetheless.

  I hope that helps.

  Cheers,
  Matthias

  0
• 

  Shesha Sreenivasamurthy

  October 11, 2024 04:21

  • 
  • 
  • 

  Thank you !

  0

Post is closed for comments.