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<p>Dear Kody,</p>
<p><br>
</p>
<p>For further Python clarification: Have you ever explicitly added
a constraint of the type you've created, or have you set the kwarg
`needscons=False`? A constraint handler will not perform its
enforcement routines unless at least one of those criteria are
satisfied.</p>
<p><br>
</p>
<p>Cheers and hope your bug is fixed,</p>
<p>Mark<br>
</p>
<div class="moz-cite-prefix">On 11/17/24 23:04, Besancon, Mathieu
wrote:<br>
</div>
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<p>Dear Kody,</p>
<p><br>
</p>
<p>Just to clarify one thing in case this induced some
confusion.</p>
<p>Constraint handlers are defined to add new constraints to the
model, while separators would be the suitable mechanism for
strengthening the LP relaxation (separators define the
algorithms that produce cuts).</p>
<p><br>
</p>
<p>If a constraint handler is still what you think is suitable
for your use case, did you implement all corresponding
methods?</p>
<p><br>
</p>
<p>Best,<br>
Mathieu<br>
</p>
</div>
<hr style="display:inline-block;width:98%" tabindex="-1">
<div id="divRplyFwdMsg" dir="ltr"><font style="font-size:11pt"
face="Calibri, sans-serif" color="#000000"><b>From:</b> Scip
<a class="moz-txt-link-rfc2396E" href="mailto:scip-bounces@zib.de"><scip-bounces@zib.de></a> on behalf of Kody Kazda
<a class="moz-txt-link-rfc2396E" href="mailto:17kk18@queensu.ca"><17kk18@queensu.ca></a><br>
<b>Sent:</b> Sunday, November 17, 2024 4:37:27 PM<br>
<b>To:</b> <a class="moz-txt-link-abbreviated" href="mailto:scip@zib.de">scip@zib.de</a><br>
<b>Subject:</b> [SCIP] Pyscipopt conshdlr enforcement</font>
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<p class="MsoNormal">Hi all,<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">I am looking to implement a constraint
handler in pyscipopt to add strengthening cuts to tighten
the LP relaxation before branching.<o:p></o:p></p>
<p class="MsoNormal">I have successfully implemented this on
other models, but for some unknown reason on the model I am
working with now I can’t get pyscipopt to enforce my
constraint handler before branching.<o:p></o:p></p>
<p class="MsoNormal">SCIP will get to over 25,000 nodes and
still not run my constraint handler.<o:p></o:p></p>
<p class="MsoNormal">I have tried all sorts of different
enforcement priorities, going as high as 1E8, so that does
not seem to be the issue.<o:p></o:p></p>
<p class="MsoNormal">Does anyone have any thoughts on what
might be causing this issue?
<o:p></o:p></p>
<p class="MsoNormal">Is there some algorithmic property that I
am not considering that may cause SCIP to not enforce a high
priority constraint handler prior to branching?<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Thank you!<o:p></o:p></p>
<p class="MsoNormal">Kody<o:p></o:p></p>
</div>
</div>
<br>
<fieldset class="moz-mime-attachment-header"></fieldset>
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