Michel Soares
Optimization Specialist at BITKA Analytics
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Recent activity by Michel Soares-
No, Gurobi does not use neural networks in its main algorithms. Look for Simplex algorithm, interior-point method and Branch and Bound for an understanding of the main algorithms used in a mathemat...
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Gurobi uses the standard IEE 754 double-precision format, which should amount to 64bits. See: https://www.gurobi.com/documentation/current/refman/real_numbers_are_not_real.html
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Hi Dominico, It is likely that, if the constraints are being violated at all, it is by a very small margin. Numerical issues are a big topic in computer science, it arises from the simplest problem...
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Hi Jonathan, A big difference between simplex and interior point methods is the ability to use well warm-starts. That is usually the reason behind simplex is usually used in the branch and bound no...
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A few things that I notice from the logs:1. You arrive at better/best solutions earlier using cutoffs. 2. In tighter cutoff scenarios, the solver takes longer to prove optimality and ends up explor...
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I am not sure if this is the cause, but it might be related to numeric problems. Have you tried slightly increasing the value for the cutoff?Additionally, can you post the logs for two runs (one wi...
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I am unaware of a way to do this.Nonetheless, it seems unlikely to me that this would be beneficial in performance. Solving LP relaxations in the the branch and bound nodes are usually quite fast a...
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Yes, different solutions come from exploring different branches/nodes of the branch and bound when solving a MIP. The solutions from the pool may also come from MIP heuristics that Gurobi uses.
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ComputeIIS can sometimes take a long time. If you are running on the command line, you can pause anytime and write the current IIS, you do not have to wait until it finishes. One strategy with IIS ...
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Hi Jordi. Regarding your IIS constraints: LoadAfterVisit_11_22_1: - 1100 C1711 - C3661 + C3727 >= 849 LoadAfterVisit_22_11_1: - 1100 C3235 + C3661 - C3727 >= 904 Let's assume C1711 is zero and C323...