A.Omidi

Dear support team, I hope you are doing well. I am trying to count the number of different solutions to a problem and have some issues.  If I write a problem as an LP format, like \(z_a + z_b = 5\...

Dear support team, I am trying to work on a scheduling problem based on its polyhedron reformulations. For that, I would like to reformulate a BigM model into its equivalent Convex hull, (CH),  for...

Dear community team, I'm trying to write a constraint in the following form: $$(a_j * (s_j!)) / L \leq 1-\gamma$$ Where \(\texttt{a}\) and \(\texttt{gamma}\) are constants and \(\texttt{s}\) and \(...

Dear support team, I'm working on an optimization problem (MIP) which in the medium/large scale takes too much time to solve optimality. Then I tried to use Gurobi heuristic parameter to invoke a f...

Dear support team,   I'm trying to solve a scheduling problem using Gurobi 9. The model is solved and the optimal solution is found. Now, I would like to use a heuristic (which an instance could be...

Dear support team,   I'm trying to solve a large scale optimization problem using Gurobi solver (V.9) on my local machine. As I have not accessed to an academic licence for Gurobi, I will need to u...

Dear community team, I have tried to solve a special knapsack problem which contains an inequality with binary parameters. AFAIK, cover cuts families can be applied to solve the standard knapsack ...

Dear support team, I was trying to solve a MIP using Gurobi and Java. I will need to turn off all pre-solving, heuristics and separating options and solve the problem using pure Branch and Bound. T...

Hello support team, I define an integer variable as following: GRBVar[][] start = new GRBVar[mach.length][item.length]; for (int m = 0; m < mach.length; m++) { for (int k = 0; k < item.leng...

Hello support team, I have worked on the transfer a GAMS/Gurobi model into the Gurobi Java API. The GAMS code is: Binary variable rank(i,k);Equations c1,c2;c1(k).. sum(i, rank(i,k)) =e= 1;c2(i).....