Ronald van der Velden
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Activity overview
Latest activity by Ronald van der Velden-
Ronald van der Velden commented,
Hi Mike, One use case could be, when you have a MIP model but want to calculate dual values (see this question). Those are not available for a MIP model, but when you fix all integer variables, the...
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Ronald van der Velden commented,
Official comment Hi Yongtao, You can find suggestions in our article How do I resolve the error "Model is infeasible or unbounded"? ; one possible reason might be that your model is not infeasible but unbounded. Ki...
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Ronald van der Velden commented,
Hi Sudheer, Here's a few more thoughts. Unfortunately we cannot go much further with modeling assistance, but other users of this community forum might be happy to jump in. If the number of loads ...
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Ronald van der Velden commented,
Dear Sudheer, Should this problem be approached as a vehicle routing problem (VRP) where the goal is to optimize the routes and truck assignments for deliveries, or should it be modeled as a logis...
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Ronald van der Velden commented,
Hi Rui, Just to be sure - Unless you're using the solution pool functionality, Gurobi does not necessarily return all optimal solutions. In general, if you feel a solution should be returned (and c...
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Ronald van der Velden commented,
Hi, My first guess would be that there is a problem with build_RMP. I believe you're constructing a completely new model in each iteration, which could be a bit slow and makes it a bit harder to co...
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Ronald van der Velden commented,
Hi Keyu, Thanks for posting here! In your example, all copies of the model live in the same (default) Gurobi environment, which is not thread-safe. Each model should live in its own, dedicated Guro...
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Ronald van der Velden commented,
Hi Julia, If the problem is a minimization problem and all you do between iterations is adding a column, this should not happen indeed, since the optimal solution from the previous iteration is sti...
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Ronald van der Velden created an article,
What is a Floating Compute Server architecture?
Components and responsibilitiesIn any architecture involving Gurobi, we have three key responsibilities: Constructing mathematical models (and processing solutions) Solving these models Licensing W...
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Ronald van der Velden commented,
Hi Sompol, Actually I believe the problem is not in your own code, but in Pyomo. It looks like this version of Pyomo calls a Gurobi function that has been removed in version 12. However, I don't se...