Jaromił Najman

1. Community
2. Modeling
3. Different Optimal Solutions from Equivalent Quadratic and Direct Formulations

Hi Muhamad, It is possible that the optimal solution point is the same but the objective value is different. A trivial example would be an objective with and without a constant. What you should che...

• View comment
• Jaromił Najman
• March 10, 2025 10:12
• 0 votes

1. Community
2. Programming
3. Handling Product of Continuous Decision Variables in MATLAB Optimization Toolbox with Gurobi

Hi Fabiana, Gurobi's MATLAB API supports quadratic (nonconvex) objectives. Please have a look at the qp.m example and the corresponding documentation. Best regards, Jaromił

• View comment
• Jaromił Najman
• February 25, 2025 15:51
• 0 votes

1. Community
2. Algorithms
3. column generation dual variables

This post is more than three 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 creat...

• View comment
• Jaromił Najman
• February 24, 2025 12:46
• 0 votes

1. Community
2. Algorithms
3. Gurobi: Built-in Function for Bender's Decomposition?

Hi Dai Nam Nguyen, Unfortunately, Gurobi currently does not support automatic Benders decomposition. As an alternative, you might want to have a look at open-source packages such as the SCIP Bender...

• View comment
• Jaromił Najman
• February 13, 2025 08:30
• 0 votes

1. Community
2. Modeling
3. False Positive of Model being Infeasible, maybe about exponential constraints

Hi Lei, Could you please update to Gurobi version 12 and try again. If you are not able to upgrade to version 12, please try setting the FuncNonlinear parameter to 1. This will tell Gurobi to treat...

• View comment
• Jaromił Najman
• February 04, 2025 14:31
• Edited
• 0 votes

1. Community
2. Programming
3. Solving Non-convex MINLP - postponed nodes

Hi Seyedkianoush, a postponed node is a node that Gurobi was not able to solve for whatever reason. It may be that a node is unbounded when it shouldn't or some numerical trouble were encountered. ...

• View comment
• Jaromił Najman
• February 03, 2025 16:49
• Edited
• 1 vote

1. Community
2. Modeling
3. How to model a piecewise linear function?

Hi Dejan, Strangely enough, it doesn't work with addGenConstrExp(). How do I get it to work? Could you please elaborate what exactly does not work? Note that you have to introduce an auxiliary va...

• View comment
• Jaromił Najman
• February 03, 2025 10:37
• Edited
• 0 votes

1. Community
2. Modeling
3. How to model a piecewise linear function?

Cann i also model functions such a power or a sigmoid function without using addGenConstrPWL?  Which command would i use for that? With version 11 you can use the addGenConstrPow method to add po...

• View comment
• Jaromił Najman
• February 03, 2025 10:37
• 0 votes

1. Community
2. Programming
3. Using a for loop for a single or specific value in variable list in constraint formulation

Hi Margi and Happy New Year, This issue is explained in the Knowledge Base article Why doesn't Gurobi support strict inequality constraints like x < a? Best regards, Jaromił  

• View comment
• Jaromił Najman
• January 03, 2025 08:21
• 0 votes

1. Community
2. Algorithms
3. An empty callback function makes the solver unable to find any feasible solution

Hi Xuan Lin, Are the techniques disabled by activating LazyConstraints inherently incompatible with lazy constraints, or is there a workaround to mitigate the slowdown? The deactivated techniques...

• View comment
• Jaromił Najman
• December 10, 2024 18:12
• 0 votes