Jonasz Staszek

Hi Tiril, you would need two indices per variable for that - one for the commodity and the other one for the route. You implement it just like any other variable: import gurobipy as gpm = gp.Model(...

Hi Jingyue, could you please share a minimal reproducible example of the code which produces such an outcome?No need to attach any data, some hard-coded inputs will do. Best regardsJonasz

Hi Chao, if your model doesn't solve after this much time, it is most likely a very difficult one. To remedy this, you might want to reformulate it or seek other ways to strengthen its formulation....

Hi Yu, it is difficult to help you based on the information you provided. What kind of difficulty are you dealing with? Also, a minimal reproducible example would be helpful. Best regardsJonasz

Hi Jonas, The update method for C++ is documented here. You can certainly add multiple new variables and only update the model every now and then. You should actually avoid calling the update metho...

You could try expressing each of the affected t variables as \(t = 7*a + b\), with \(a, b\) being integers and \(b \in [0,6]\) Then, \(b\) is your reminder and you can use it in the constraint you ...

Hi Simon, The documentation suggests that quadratic constraints handle equality constraints. How do you know that the constraints were converted to an inequality form? Did you store the model someh...

Cross-posted here.

Hi Jingyue, this article should shed some light. Writing a solution to an Excel sheet can be done for example by iterating over variables of the model and retrieving their value in each scenario, a...

Hi Tiril, 1. What are \(U1, U2\)? Are they variables? If so, you need to define them as such upfront, for example by: U1 = m.addVars(alternative, criteria, vtype="C", name="u1")U2 = m.addVars(alter...