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<p><span lang="EN-US">Hi all,<o:p></o:p></span></p>
<p>I'm working on a custom cut selector in SCIP 8.0.0 and using the barrier algorithm in diving mode, following the method from
<a href="https://github.com/Opt-Mucca/Analytic-Center-Cut-Selection" target="_new">
this GitHub repo</a>. Specifically, I compute the analytic center<span lang="EN-US">s</span> of the optimal face<span lang="EN-US"> and the LP polyhedron at the current node
</span>by doubling the original objective and setting it to 0 in diving<span lang="EN-US"> mode, respectively</span>.</p>
<p>I use Gurobi as the LP solver and apply the following diving settings:<span lang="EN-US"><o:p></o:p></span></p>
<p><span lang="EN-US">lp/initalgorithm = b <o:p></o:p></span></p>
<p><span lang="EN-US">lp/resolvealgorithm = b <o:p></o:p></span></p>
<p><span lang="EN-US">lp/checkdualfeas = FALSE <o:p></o:p></span></p>
<p><span lang="EN-US">lp/disablecutoff = 1 <o:p></o:p></span></p>
<p><span lang="EN-US">lp/solutionpolishing = 0 <o:p></o:p></span></p>
<p><span lang="EN-US">lp/checkstability = FALSE <o:p></o:p></span></p>
<p><span lang="EN-US">lp/checkfarkas = FALSE <o:p></o:p></span></p>
<p><span lang="EN-US">lp/presolving = FALSE // added by me <o:p></o:p></span></p>
<p><span lang="EN-US">lp/scaling = 0 // added by me <o:p></o:p></span></p>
<p class="MsoNormal">Everything runs fine in normal mode, but in debug mode I hit this assertion error:<span lang="EN-US"><o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">scip/src/lpi/lpi_grb.c:4116: SCIPlpiGetObjval: Assertion `lpi->solstat != GRB_OPTIMAL || oval == obnd' failed.<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal">oval holds the correct objective value, but obnd is -1e+100.<span lang="EN-US"><o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">Any ideas on what might be causing this? If there is a better selection of diving settings, I’d be happy to learn that as well.<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">Best regards, <o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt"><o:p> </o:p></span></p>
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<p class="MsoNormal"><b><span lang="TR" style="font-family:"Calibri",sans-serif;color:#333333;mso-ligatures:none">Selin Bayramoglu<o:p></o:p></span></b></p>
<p class="MsoNormal"><span lang="TR" style="font-family:"Calibri",sans-serif;color:#333333;mso-ligatures:none">Ph.D. Student<o:p></o:p></span></p>
<p class="MsoNormal"><b><span style="font-family:"Calibri",sans-serif;color:#333333;mso-ligatures:none">H. Milton Stewart School of Industrial and Systems Engineering</span></b><span style="font-family:"Calibri",sans-serif;color:black;mso-ligatures:none"><br>
</span><span style="font-family:"Calibri",sans-serif;color:#333333;mso-ligatures:none">Georgia Institute of Technology</span><span style="font-family:"Calibri",sans-serif;color:black;mso-ligatures:none"><o:p></o:p></span></p>
<p class="MsoNormal"><o:p> </o:p></p>
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