Marcus Garvie

Thank you. My next step is giving Gurobi a long time to tune a smaller version of the model.

Thank you. My plot is showing only the phase 1 stage. With regard to your second question, as I mentioned, if the time is greater than the NoRelHeurTime Gurobi runs basically indefinitely. I was in...

Ok, I can add a bit more information to this question. I tried the strategy of setting NoRelHeurTime to infinity for my very big BLP problem and ran it over night. I then plotted relaxation numbers...

Thanks Mario.That is useful. I had thought that in Gurobi 'MIPFocus = 1' and 'SolutionLimit = 1' roughly corresponds to 'set emphasis mip 1' and 'set mip limits solutions 1' in CPLEX, respectively....

Thank you Jaromił. Was Gurobi able to solve these smaller models in a decent amount of time? Yes. For a model that is very similar, Gurobi solved it in about a minute! Another related model (but ...

Thank you Matthias, that is very helpful. So as I explore the effect of different parameter sets I know what to look for. Best, Marcus.

Hi Matthias, we didn't deliberately construct a hard model. After a years' worth of work we managed to convert the Eternity puzzle into an LP problem. This is a notoriously difficult tiling problem...

Hi Mathias, thank you for your comments. Yes I do know that the problem I am trying to solve was deliberately constructed to be difficult. When you suggest disabling cutting planes do you mean set ...

Hi Jaromił, just an update. With smaller model I played around with the parameters quite a bit and also tried tuning. With your help I found the following parameter choices gave the greatest improv...

Hi Jaromił, gosh, there is a lot to try. I do have a smaller problem but it seems to be solved vey quickly and doesn't suffer from the same delays at the root node. I did try tuning the smaller mod...