Robert Fourer

You are setting gurobi_options twice: option gurobi_options 'timelimit=100 outlev=1 mipgap=0 mipfocus=3';option gurobi_options 'logfile=C:\AMPL\2023_01_29\Replication01\logfile.temp';  The second s...

When Gurobi 10.0 for AMPL is released (very soon now) there will be an option writepresolvedprob that works the same as the current option writeprob except that it writes -- to the specified file -...

Use AMPL's \(\texttt{.priority}\) suffix to set priorities of variables for Gurobi. For example: suffix priority IN;let {i in ACTIVITIES} Y[i].priority := 100;let {i in ACTIVITIES, t in 1..T} X[i,t...

Gurobi's presolve was being turned off when called from AMPL, but was on when called from the R API. This can be seen from the option presolve=0 echoed in the AMPL listing, and the presence of thes...

You seem to be asking a new question about time limits, which is only indirectly related to the previous posts in this thread. Also, your question is more about how to use AMPL than how to use Guro...

That is a correct way to set the Gurobi time limit, and it's verified to be working with Gurobi 11.0 for AMPL. To be sure you are using it correctly, look for timelimit=7200 or lim:time=7200 in AMP...

Hey bot! Couldn't you use Model.addGenConstrExp()?

Does the setting of Gurobi parameter PreQLinearize make any difference in this situation?

The reset_initial_guesses setting works, but if it does not make a big difference, then you can conclude that the slower solves are likely not due to warm starts. Here are some additional checks th...

I wouldn't expect that warmstarting would slow down Gurobi's solution process. But you can try turning off warmstarting by setting "option reset_initial_guesses 1;" in AMPL. It is possible that the...