Eli Towle

Hi Hans, First, we modify the subtour function to return the full list of cycles, not just the shortest cycle. That is, we change return cycles[lengths.index(min(lengths))] to return cycles Then, ...

Hi Jozsef, Before adding a constraint that includes v2, can you try first adding v2 to the model with the GRBModel.addVar() method (like you do with v1)? You declare v2 to be of type GRBVar, but it...

Hi Buddi, Could you try adding the constraint load_level(T) * power(T) = installed_capacity for each time T? Gurobi 9.0 supports bilinear constraints like this. When doing this, be sure to set the ...

Hi Hans, Thanks for bringing this to our attention! The underlying issue has been fixed for subsequent releases of Gurobi. Eli

Hi Hans, Could you post your minimal working example? Thanks! Eli  

Hi Chags, We will discuss this with you directly through our support portal. Thanks! Eli

Hi Jolly, I addressed a lot of the issues with this code in my previous response. The main problems are: T_(i+1) is not a valid Python variable name. You only defined a Python variable T_i. The le...

Hi Quang, Can you check if there is a round-off error in either of your scripts? E.g., in Python, we sometimes see calculations like this: >>> 0.1 + 0.20.30000000000000004 Thanks,Eli

Hi Matheus, This behavior is expected. At the root node, Gurobi finds a potential new heuristic solution with objective value 2938. This calls your where == GRB_CB_MIPSOL callback. In your callbac...

Hi Baptiste, I wonder if adding some tolerances to your callback function would help. In particular, try checking if the objective value is greater than \( 0.99999 \) (1 - 1e-5). If so, identify th...