Limit solve time/iterations/... or cancel solving process

[SashmanGH]

Hi everyone,
I need to limit the solver duration. It would be great if I could let the solver run for a given duration like 5 minutes. If that is not possible, would it be possible to run the solver in background and then call a function to stop the solver? Or if even that won't work, could I tell the solver to do one iteration at a time so I could check the elapsed time inbetween iteration?

Thanks.
Sascha

[SashmanGH]

Hi,
thanks for the quick reply. Sorry, my description was to short. I use Sonnet/SonnetWrapper to call CBC from c#. Here is an example:
` Sonnet.Model model = new Sonnet.Model("GoogleExample");

        Variable x = new Variable(VariableType.Integer);
        Variable y = new Variable(VariableType.Integer);

        model.Add(x + 7 * y <= 17.5);
        model.Add(0 <= x <= 3.5);
        model.Add(0 <= y);
        model.Objective = new Expression(x + 10 * y);

        
        Solver solver = new Solver(model);
        
        solver.Maximise();

`
From you linked example I can see a method setDblParam, but I can't find it in the .Net version. Am I missing something?

Thanks,
Sascha

[jhmgoossens]

Hi,
Apologies for the confusion. I didn’t realise your question was for Sonnet—I thought it was for cbc.. I deleted my original answer.

For sonnet, the short answer is to either add the “sec” solver arg or cbcmodel setMaximumSeconds:

Solver solver = ….
OsiCbcSolverInterface osiCbc = solver.OsiSolver as OsiCbcSolverInterface;
osiCbc.AddCbcSolverArgs("-sec", "5");

or to use the setMaximumSeconds of CbcModel:
osiCbc.getModelPtr().setMaximumSeconds(5.0;
Which should work again since CBC #467 was closed. See test/SonnetTest/Sonnet_CbcTests.cs

For an example of how to use CBC Callbacks from sonnet, see also Sonnet_CbcTests.cs

For background: Sonnet relies on Osi, but Osi doesn’t include things like time limits. Therefore, these have to be done solver-specifically.
Does this help?

[SashmanGH]

Hi,
thanks for your answer. Works as expredted. getModelPtr().setMaximumSeconds is still marked obsolete in my version so I used AddCbcSolverArgs.
Now that I look at it, it seems to be a very basic question. So, thanks for you patience.

Sascha