[Scip] How to terminate SCIP earlier?

[lixiangyong at 163.com]

Dear Dr. Gerald,

Thanks,  I have used SCIPinterruptSolve() to terminate my solving process since I know the current incumbent is the optimal solution.

BTW, can you tell me the advantage of  calling SCIPsetObjIntegral() if I know any feasible solution should have an integer objective value?  Can it speed up the solving process?


Thanks,


Xiangyong
 
From: Gerald Gamrath
Date: 2014-09-23 17:16
To: lixiangyong at 163.com; scip
Subject: Re: [Scip] How to terminate SCIP earlier?
Dear Xiangyong Li,

if you know that every feasible solution will have an integer objective value and therefore want to stop the solving process when the dualbound is larger than primalbound - 1, you can just inform SCIP that this is the case by calling SCIPsetObjIntegral().

Otherwise, you can call SCIPinterruptSolve() to stop the solving process, but SCIP will then print that it was interrupted, not that it was solved to optimality.

Best,
Gerald

Am 23.09.2014 um 10:02 schrieb lixiangyong at 163.com:
Dear all,

I am using SCIP to implement my branch and price algorithm.
Now I want to terminate the SCIP earlier since I can judge the problem has been optimally solved when some condition is satisfied.  
Suppose UB and LB be the objective value of best incumbent and the best remaining node in the branch and bound tree.
For my instances considered, SCIP has optimally solved one instance if UB-LB < 1.

Can you tell me how to set the earlier termination condition in SCIP?

Thanks,


Xiangyong Li




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