# Eli Towle

Gurobi Staff
• Total activity 1066
• Last activity
• Member since
• Following 0 users
• Followed by 1 user
• Subscriptions 420

## Activity overview

Latest activity by Eli Towle
• Eli Towle commented,

Pyomo doesn't support all of the features available in the native Gurobi Python API. However, if you're using the "persistent" Gurobi interface, you can access the underlying $$\texttt{gurobipy}$$ ...

• Eli Towle commented,

If you set the InfUnbdInfo parameter, Gurobi will supply you with an unbounded ray that proves the model is infeasible. You can query this ray by examining the UnbdRay attribute of each Var object....

• Eli Towle commented,

By default, variables added via Model.addVar() or Model.addVars() have a lower bound of $$0$$. If the $$Z$$ variables are free, you should define them as follows: Z = m.addVars(Ind, lb=-GRB.INF...

• Eli Towle commented,

Here are two ways to view new incumbent solutions as Gurobi finds them: Query the new incumbent solution in a MIPSOL callback. In Python, this can be done with Model.cbGetSolution(). You might fin...

• Eli Towle commented,

Gurobi's read() function reads the model file into a Model object. To print the content of a model file, use Python's built-in open() function: with open("Outputs/model_v1.mps", "r") as f: conte...

• Eli Towle commented,

Gurobi doesn't return a certificate of optimality that you can use to manually verify that the solution to your non-convex problem is optimal. You have access to the optimal solution, which can be ...

• Eli Towle commented,

Yes, Gurobi solves non-convex quadratic problems to global optimality, subject to the specified optimality tolerance. Gurobi solves such problems using a spatial branch-and-bound algorithm. The Non...

• Eli Towle commented,

The example problem is a continuous linear problem, so it is not solved as a MIP and there is no MIPGap to report. The model status is $$\texttt{GRB.OPTIMAL}$$, meaning the problem was solved to op...

• Eli Towle commented,

It looks like you just need to set the NonConvex parameter to 2 to direct Gurobi to solve the model (which is made non-convex by the quadratic equality constraints): model.Params.NonConvex = 2 Note...

• Eli Towle commented,

Which part of the implementation do you need help with? Your code looks okay, depending on how you defined $$\texttt{TK}$$, $$\texttt{R}$$, $$\texttt{A}$$, and $$\texttt{E}$$. For example, ...