[SCIP] Is there any way that I can reproduce the numbers of iterations and branch-and-bound nodes when using MIP

[Tseng, Tsung Yuan]

Dear SCIP team,

I use python and SCIP backend to solve the MIP problem.

I try to modify my MIP model, such as adding additional constraints, change the format of the constraints, and so on, to see if the modification will help with the solving procedure.  For example, I look at the number of interactions and branch-and-bound nodes to see whether it is helpful. If both numbers decrease, I will say the model is better.

However, when I don't change the model, e.g., constraints, variables, the iterations and nodes outputting by the solver are still different, which is bad if I want to manipulate the formulation because I cannot tell if these are affected by the modified model or the randomness in the solver.

I also try

`
model.SetSolverSpecificParametersAsString("randomization/lpseed=0")
model.SetSolverSpecificParametersAsString("randomization/permutationseed=0")
model.SetSolverSpecificParametersAsString("randomization/randomseedshift=0")
`

but still get different numbers of iterations and nodes after running the same piece of code.

In the nutshell, is there any feature that can make the solver reproduce the number of iterations and nodes with the same code? (Of course in the same setting)

Thank you very much.



Best Regards,

Tsung Yuan Tseng

Master Student @ RWTH M.S. Robotic Systems Engineering

My personal website: https://middleyuan.github.io/
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