Originally posted by: gtoptimizer

Hello,

In the callable library, is there a way to set a parameter, e.g. CPX_PARAM_VARSEL, inside a control callback?

For instance, if I want CPLEX to switch branching strategies at some point during the search, is that possible?

My guess is that the answer is no, since the environment is passed to the callback as CPXCENVptr, which cannot be modified, but I'm hoping there exists some workaround.

Thanks!

The answer is indeed "no": you are not allowed to modify parameters while a solve is running.

The workaround is to stop the solve, change the parameter and then solve again. The second solve should leave off where the previous one started.