Maliheh Aramon

Hi Jonathan,  The warning message means that the basis became singular. Therefore, the columns involved in the singularity (1 column in your case) needed to be dropped and replaced by another colum...

Hi,  Gurobi has a parameter named ScaleFlag that automatically scales the model. Automatic scaling implicitly changes feasibility tolerance values. The internal substitution of \(x\) with \(0.1x^{...

Hi Teemu,  It would be easier to define variables as Gurobi Var objects and not Gurobi MVar objects. See the script below as an example of how to implement this: import gurobipy as gpfrom gurobipy...

Hi Hamza,  Please have a look at the article "How do I determine why my model is infeasible?".  The first step is to compute an IIS using the Model.computeIIS() method. The Gurobi Optimizer first n...

Hi Birkan,  The \(l\), \(m\), and \(u\) are known input values to the problem. They are not decision variables. You need to remove the variable definitions \(\texttt{lijlog}\), \(\texttt{mijlog}\)...

Hi Birkan,  To implement the expression \(\sum_i \sum_{j \neq i} \ln w^L_i - \ln w^U_j\) as part of the objective function, you would need to define auxiliary variables \(u_i\) and \(v_j\) such tha...

Hi,  The barrier algorithm terminates if 1) the primal solution is feasible 2) the dual solution is feasible and 3) the normalized duality gap (the difference between primal and dual objective valu...

Yes, Rahul's point is valid.  The expression \( \texttt{(u[i]==1 for i in range(9))}\) is a generator and the expression \(\texttt{(x[i+1] == x[i] + 0.5 for i in range(9)})\) is another generator. ...

Hi,  Let us use a simpler example to understand the error. Running the script below results in the exact same error: TypeError: unsupported operand type(s) for -: 'generator' and 'NoneType' impor...

Hi,  The Gurobi Optimizer solves the model in the presolved space. Since presolve can change the meaning of "feasible within tolerances", when the optimal solution is mapped from the presolved spac...