Jacob Jin

Indeed, I was computing the runtime of the dual problem in Benders decomposition. I defined the dual model outside the callback function. In each iteration, I redefined the dual's objective functio...

Hi,I want to know to define a private variable with Gurobi in Julia, just like: model._counter = 0

Hi, the code disappeared. Is there any reference code?

I have verified that all the lazy constraints' formulations are correct。。。

if len(tour) < n: model.cbLazy(gp.quicksum(model._vars[i, j] for i, j in combinations(tour, 2))

Hi, Jaromił! When I retrieve the false LB,  if status == 2:### add optimality cut ### When the UB and LB are not equal, add the optimality cut if abs(UB - LB) >= 0.01: model.cbLazy(mod...

Hi, Jaromił! It works, but I don't know why my former code worked. Apparently, it retrieve the false LB... Is there any detailed explanation about the work process of callback function(I have viewe...

I don't know why...? Can you give me some hints? Thank you so much~

Hi, Jaromil! Thank you for replying me. I have some issues to consult... (1) I have printed the linear expression and it's right. To testify whether the callback function works well, I add the line...

Hi, I have the same question: if where == GRB.Callback.MIPSOL: ### Retrieve the cuurent value of the master problem r_1 = np.array( [[model.cbGetSolution(model.getVarByName('r_' + str(...