Vincent

Sometimes, when redundant variables are removed — those that take a value of 0 at optimality — the overall solve time increases. The reduced model has fewer variables, but the solver takes longer t...

Sometimes, I encounter a situation where my model's runtime decreases when the number of scenarios slightly increases. I'd appreciate any insight into the potential reasons, as this seems counterin...

I have two decision variables defined as x = m.addVars(((i, j) for i, j in arcs if f[i][j] == 0),vtype=GRB.BINARY, name='x')y = m.addVars(((i, j) for i, j in arcs if f[i][j] == 1),vtype=GRB.CONTINU...

I have defined a variable using addVar() method as follows: for i in range(no_nodes): for j in range(no_nodes): for k in O: if fij[i][j]==1 or mij[i][j]==1: x[i,j,k] = m.addVar(vtyp...

Hi, - When I select MIPFocus=1, the optimal solution is equal to 1.79542 with 0.0000% gap.- When I select MIPFocus=3, the optimal solution changes to 1.75932 with 0.0000% gap. I cannot understand w...

I have a model with three objectives and defined three environments (env1, env2, and env3) for each pass. I am solving this multiobjective problem with a hierarchical approach and wondering if ther...