Ronald van der Velden

Hi Quin, Not exactly sure what's causing this. One silly trick I've used several times for debugging, is to literally receive the GRB_LICENSE_FILE environment variable from within Python and then t...

Hi Johnpaul, We don't have a full example available. However, once you have the code for constructing and solving the full model, the changes are relatively small. Here are the tricks you need: Af...

Hi Sergei, Have you looked into indicator constraints already? You could create a single binary variable. Then you create one indicator constraint saying if my binary is 0 then constraint 1 must ho...

Hi Quin! These are interesting, but also broad questions :-) I'll just share the first that comes to mind, but others may have additional ideas and you may want to add details to guide us in the ri...

In addition to the above - to answer your last question explicitly: No, that approach won't work since both parts of the objective use the same index 0. If they would use a different index (0, 1) f...

Hi Lorenz, You mentioned "Since my whole model is very complex for large model". Does this mean the model formulation is as above, but runtime increases as you add workers/shifts/days? Can you give...

Does the error occur at the last line of your code (model.update) or in a different place? It would typically occur when you try referencing a constraint later, but I notice you don't store the res...

Hi, What I meant was - have you implemented the approach I suggested and/or tested the model that is discussed in Gurobi Finance? If that leads to errors, could you share a reproducible piece of co...

What is the problem you're observing? 

Hi, Because of your question and you mentioning "risk", I suspect you may be interested in the Gurobi Finance project. The linked page includes a nice and clean way to express this risk formula usi...