<html><head><meta http-equiv="content-type" content="text/html; charset=ISO-8859-1"><style>body { line-height: 1.5; }blockquote { margin-top: 0px; margin-bottom: 0px; margin-left: 0.5em; }body { font-size: 12pt; font-family: Calibri; color: rgb(0, 0, 0); line-height: 1.5; }</style></head><body>
<div><span></span>Dear Dr. <span style="font-size: 12pt; line-height: 1.5; background-color: window;">Ambros,</span></div><div><span style="font-size: 12pt; line-height: 1.5; background-color: window;"><br></span></div><div><span style="font-size: 12pt; line-height: 1.5; background-color: window;">I want to know the </span><span style="font-size: 12pt; line-height: 1.5; background-color: window;">advantage of calling SCIPsetObjIntegral() if at the beginning I </span><span style="font-size: 12pt; line-height: 1.5; background-color: window;">know any feasible solution should have an integer objective value? Can</span><span style="font-size: 12pt; line-height: 1.5; background-color: window;"> it speed up the solving process?</span></div><div><span style="font-size: 12pt; line-height: 1.5; background-color: window;"><br></span></div><div><span style="font-size: 12pt; line-height: 1.5; background-color: window;">Thanks,</span></div><div><span style="font-size: 12pt; line-height: 1.5; background-color: window;"><br></span></div><div><span style="font-size: 12pt; line-height: 1.5; background-color: window;">Xiangyong Li</span></div><div><span style="font-size: 12pt; line-height: 1.5; background-color: window;"><br></span></div>
<blockquote style="margin-top: 0px; margin-bottom: 0px; margin-left: 0.5em;"><div> </div><div style="border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0cm 0cm 0cm"><div style="PADDING-RIGHT: 8px; PADDING-LEFT: 8px; FONT-SIZE: 12px;FONT-FAMILY:tahoma;COLOR:#000000; BACKGROUND: #efefef; PADDING-BOTTOM: 8px; PADDING-TOP: 8px"><div><b>From:</b> <a href="mailto:gleixner@zib.de">Ambros Gleixner</a></div><div><b>Date:</b> 2014-09-24 08:21</div><div><b>To:</b> <a href="mailto:scip@zib.de">scip</a>; <a href="mailto:lixiangyong@163.com">lixiangyong@163.com</a></div><div><b>Subject:</b> Re: [Scip] How to terminate SCIP earlier?</div></div></div><div><div>Dear Xiangyong,</div>
<div> </div>
<div> </div>
<div>Am 24.09.2014 02:08, schrieb lixiangyong@163.com:</div>
<div>> Dear Dr. Gerald,</div>
<div>></div>
<div>> Thanks, I have used SCIPinterruptSolve() to terminate my solving</div>
<div>> process since I know the current incumbent is the optimal solution.</div>
<div>></div>
<div>> BTW, can you tell me the advantage of calling SCIPsetObjIntegral() if I</div>
<div>> know any feasible solution should have an integer objective value? Can</div>
<div>> it speed up the solving process?</div>
<div> </div>
<div>Yes. If (in minimization) the primal bound is x and the lower bound is </div>
<div>greater than x - 1, the solution process can be stopped already.</div>
<div> </div>
<div>Best regards,</div>
<div>Ambros</div>
<div> </div>
<div> </div>
<div>></div>
<div>></div>
<div>> Thanks,</div>
<div>></div>
<div>></div>
<div>> Xiangyong</div>
<div>></div>
<div>> *From:* Gerald Gamrath <mailto:gamrath@zib.de></div>
<div>> *Date:* 2014-09-23 17:16</div>
<div>> *To:* lixiangyong@163.com <mailto:lixiangyong@163.com>; scip</div>
<div>> <mailto:scip@zib.de></div>
<div>> *Subject:* Re: [Scip] How to terminate SCIP earlier?</div>
<div>> Dear Xiangyong Li,</div>
<div>></div>
<div>> if you know that every feasible solution will have an integer</div>
<div>> objective value and therefore want to stop the solving process when</div>
<div>> the dualbound is larger than primalbound - 1, you can just inform</div>
<div>> SCIP that this is the case by calling SCIPsetObjIntegral().</div>
<div>></div>
<div>> Otherwise, you can call SCIPinterruptSolve() to stop the solving</div>
<div>> process, but SCIP will then print that it was interrupted, not that</div>
<div>> it was solved to optimality.</div>
<div>></div>
<div>> Best,</div>
<div>> Gerald</div>
<div>></div>
<div>> Am 23.09.2014 um 10:02 schrieb lixiangyong@163.com:</div>
<div>>> Dear all,</div>
<div>>></div>
<div>>> I am using SCIP to implement my branch and price algorithm.</div>
<div>>> Now I want to terminate the SCIP earlier since I can judge the</div>
<div>>> problem has been optimally solved when some condition is satisfied.</div>
<div>>> Suppose UB and LB be the objective value of best incumbent and the</div>
<div>>> best remaining node in the branch and bound tree.</div>
<div>>> For my instances considered, SCIP has optimally solved one</div>
<div>>> instance if UB-LB < 1.</div>
<div>>></div>
<div>>> Can you tell me how to set the earlier termination condition in SCIP?</div>
<div>>></div>
<div>>> Thanks,</div>
<div>>></div>
<div>>></div>
<div>>> Xiangyong Li</div>
<div>>></div>
<div>>></div>
<div>>></div>
<div>>></div>
<div>>> _______________________________________________</div>
<div>>> Scip mailing list</div>
<div>>> Scip@zib.de</div>
<div>>> http://listserv.zib.de/mailman/listinfo/scip</div>
<div>></div>
<div>></div>
<div>></div>
<div>> _______________________________________________</div>
<div>> Scip mailing list</div>
<div>> Scip@zib.de</div>
<div>> http://listserv.zib.de/mailman/listinfo/scip</div>
<div>></div>
<div> </div>
<div>-- </div>
<div>____________________________________________________________</div>
<div>Ambros M. Gleixner</div>
<div>Zuse Institute Berlin - Matheon - Berlin Mathematical School</div>
<div>http://www.zib.de/gleixner</div>
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