Charitha Buddhika Heendeniya

Hello all, I'm testing a re-optimization method that goes as follows.  Initialize model model.solve() --> solution stored as model.sol Edit model.sol by removing solutions to some variables (incl. ...

I want to know if I can create a MIPSOL callback routine like the one below. Where MIPSOL: Add a lazy constraint to the model, Check if the incumbent solution is still feasible, If feasible: get t...

Dear all, I want to start this thread to share tips/ suggestions for using lazy constraints (using the attribute or callback). Below I share some of my experiences on this, and I would like if othe...

Dear all, I'm trying to use MemLimit parameter  e = Env("gurobi.log", params={'MemLimit': 31, 'PreSparsify': 1, 'MIPFocus': 3, ...

I'm trying to write a constraint (for a task scheduling problem) where I want to say "a maximum of n tasks can overlap". I have the following variables, x(i, j): Task j follows task i (variable) T(...

Dear community, Below is a screenshot of a section of the log produced by Gurobi. I want to understand what this means, especially what a phase-1 solution is, and how I can use that information. I ...

Dear community, I'm trying to model a very basic VRP problem with time constraints. In the code below, please check the time constraint I wrote in two different ways. The constraint in the comment ...

I came across an interesting behavior of Gurobi. After writing down a series of constraints, I received "IndexError: invalid index to scalar variable." I was able to fix this error just by reorderi...

Dear Community, I have defined the following variables. # Binary indicator variable: 1 if bus b is leaving node i at time t, else 0n0 = model.addVars(n_cars, n_nodes, time_steps, vtype=GRB.BINARY, ...

Dear community, I have a constraint of the form: if x(i, j, k) == 1: sum (over t) {p(i, j, k, t) * u(i, j, t)} == 1 Could you please advise me on how to model it using Gurobi? Here x, u, and t are ...