Silke Horn

I am glad you got the matrix definition to work. The objective function needs to be a linear or quadratic expression, which, unfortunately, the rank of a matrix is not. (In fact, it is not even con...

The batch jobs will run on a compute server and whether they are executed in parallel or sequentially depends on that compute server's load and job limit. With a job limit of at least 2 and no othe...

You can certainly create a numpy matrix with your variables on the diagonals; e.g. Z = np.diag([z[i] for i in arcs]) but the question is what you want to do with this matrix once you have it...

Hi Sina, You cannot get information about the branching. (Also note that the variables that Gurobi branches on may not be your variables at all since the model is transformed during presolve.) As f...

The getValue() method evaluates a linear expression in a solution. You can only call it once Gurobi knows a solution, i.e., you need to call optimize() before you can call getValue(). Silke

I think that more nodes or more tasks might make sense if you wanted to do concurrent optimization, but since the solver gets stuck in the root, I don't expect this to help. As for the memory, Guro...

Hi Jennifer, Yes, with the bounds I meant exactly what you say. Find an upper and lower (if that's not already 0) bound on the integer variables. Otherwise, the bounds will be assumed to be +/- 2 b...

There are a few things I notice from your log: First of all, the error message from the scheduler says TIMEOUT. So I guess more time would help. :-) Why does it time out? Is there a hard limit on ...

Hi Buddi, Welcome to Gurobi! To define sets, you can use anything that Python offers. E.g. you could define your sets using starting_city = {"City1", "City2", "City3"} and ending_city = starting_ci...

Hi Yutaka, Do I understand correctly that you want to add a constraint containing a term like the following? $$\sum_{i=0}^m \frac 1{\sqrt{V_i}}$$ What are the \(V_i\)? Are those decision variables?...