Eli Towle

Hi Ibtissam, The issue is with this line: A = sum(y) You defined y to be a standard Python dictionary, and taking the sum of this dictionary object doesn't accomplish what you want: >>> sum(y)3 To ...

Hi, Did you run the Gurobi MATLAB setup script included in your Gurobi installation? See here for more information. Eli

Hi Antonio, Yes, you can do this by setting the SolutionLimit parameter to 1. There are a variety of other ways you can direct Gurobi to terminate early. For example, you can tell Gurobi to termina...

Hi Marcela, I think the problem is with this set of constraints: AllNodesVisited={i: quicksum(x[i,j,camion] for j in Nodes if i!=j for camion in Camiones) for i in Nodes} #(2.2)vrp.addConstrs(AllNo...

Hi Edgar, Thanks for reporting this. This issue is fixed in Gurobi 9.0.1, which was released a few days ago. Eli

Hi Ibtissam, Gurobi 9.0 supports optimization for models with general (convex or non-convex) quadratic constraints and objectives. Unfortunately, because \( x^3 \) is a cubic expression, it is not ...

Hi Ari, We can do this by introducing an auxiliary n-dimensional MVar \( u = Dx \) and a nonnegative one-dimensional MVar \( y = c^\top x \). Then, we add the constraint \( u^\top u \leq y^2 \). Fo...

Hi Jerry, Let \( W \) be number of available workers and \( S \) the number of shifts. Let \( c_i \) be the cost of paying worker \( i = 1, \ldots, W \) to work one day. Let \( r_j \) be the requir...

Hi Sagnik, Adding two-sided constraints was never supported in Gurobi 8.1.1. This is noted in the Gurobi 8.1.1 documentation here: "Note that double inequality constraints, like 1 <= x + y <= 2 or ...

Hi Parisa, You are correct, there is no built-in "argmax" function in Gurobi, nor does Gurobi accept arbitrary functions like np.argmax in its constraints or objective. This should be possible to m...