Tobias Achterberg

I don't understand why you want to use a callback function here. Inside a callback, you cannot modify or extend the model that you are currently solving. It sounds more like you want to have an out...

That is not a particularly large model. But it is hard to say how you can improve your model without knowing anything about it. Would it be possible to send me your *.mps file? I would like to take...

Yes, using an indicator is the right way to go. And it is very easy, you just need to invert the direction of the indicator. Instead of f_r > 0 -> i_r = 1 you would enforce i_r = 0 -> f_r <= 0 This...

If you are talking about a trial license, this is restricted to models with at most 2000 columns and 2000 rows.

This question is very hard to answer, because just like in MILP, the size is not necessarily the most important factor when it comes to the time needed to solve a model. The more important aspect i...

The "NoRelHeuristic" parameter is undocumented. Just set it to 1 in order to activate the heuristic. You cannot predict when new incumbent solutions will be found and how their quality will be. Of ...

No, this is not directly possible. In constraint programming, such a constraint is refered to as "element constraint", i.e., you have a decision variable as the index into some array. If your m_j v...

Gurobi only supports products of pairs of variables, not triples. To overcome this issue, you need to introduce auxiliary variables and build the more complex expression using those. For example, i...

I fear that you have to ask this question in the Pyomo community. Gurobi does not try to call any program that is called "xx". I think this must come from Pyomo.

You cannot parallelize the calls to addConstrs(). But maybe you can parallelize the construction of the set of constraints that you add. For example, you could try building 8 different sets of cons...