I have a dummy question that I need to know its answer. I'm working on a project that requires AMPL and CPLEX as a solver. Now this problem normally takes more than 140 seconds to be solved. While I was searching, I came into an option called timelimit. I used this option with value option cplex_options 'timelimit=5'and the results were shown within 5 seconds. Now my questions is, does the output meet all the constraints and is within the boundaries I set in the code? Or did I just terminate the process and the results were the current "being processed" data? Thanks for helping.
If you don't set the timelimit parameter, the run time is the time to get to a provably optimal solution within the relative tolerance (default is 1e-6). By setting a time limit, you are telling cplex to stop at 5 seconds. In that case, it will return the best solution it has found, regardless of the quality of the objective function. cplex will not, however, give you a solution that violates constraints. If it can't find a feasible solution in the time allotted, then you will not get a solution. You can check the exitcode suffix of the model to see if there was a solution found.