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<p>Dear Lan,</p>
<p><br>
</p>
<p>it may happen that SCIP was not able to solve the LP at a node to
optimality, e.g., because of numerical issues. In that case,
branching is performed on pseudo candidates, i.e., the
BRANCHEXECPS callback is called. Probably, you did not implement
this, so that SCIP called the next-best branching rule which then
created two child nodes.</p>
<p><br>
</p>
<p>Best,<br>
Gerald<br>
</p>
<p><br>
</p>
<p><br>
</p>
<div class="moz-cite-prefix">Am 27.02.20 um 11:53 schrieb Ngô Lan:<br>
</div>
<blockquote type="cite"
cite="mid:29b65997c2ff4a32ad46eeb4cab985c4@aalto.fi">
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<p>Hi,</p>
<p><br>
</p>
<p>A bit more info: I printed out the parents of that node and
the node type of its parent is <span style="font-size: 12pt;">SCIP_NODETYPE_JUNCTION
(</span><span style="font-size: 12pt;">fork without LP
solution) :</span></p>
<p><span style="font-size: 12pt;"></span><span style="font-size:
12pt;">curr_node: 5085</span></p>
<div>parent1: 5082, type 6</div>
<div>parent2 5065, type 6</div>
<div>parent3 5061, type 8</div>
<div><br>
</div>
<div>The latest node that was entered before 5085 is 5065. For
node 5065, I think scip already found an LP solution for it
but somehow its type is still 6. And the branching tree jumped
over 5082 to 5085 (both was not created by me). I would be
grateful if someone can explain to me the behavior. Thank you
in advance.</div>
<div><br>
</div>
<div>Best,</div>
<div>Lan</div>
<br>
</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 Ngô Lan
<a class="moz-txt-link-rfc2396E" href="mailto:lan.ngo@aalto.fi"><lan.ngo@aalto.fi></a><br>
<b>Sent:</b> 25 February 2020 16:32:28<br>
<b>To:</b> <a class="moz-txt-link-abbreviated" href="mailto:Scip@zib.de">Scip@zib.de</a><br>
<b>Subject:</b> [SCIP] Entering a node that was not created</font>
<div> </div>
</div>
<div>
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style="font-size:12pt;color:#000000;font-family:Calibri,Helvetica,sans-serif;"
dir="ltr">
<p>Hi all,</p>
<p><br>
</p>
<p>During my branch and price implementation, I got a strange
error: SCIP tried to enter a node that was not created
before. I checked again all the time I used SCIPcreateChild
and printed out the node number but that node was never
created. Also, my program is currently only at depth 4 but
that node is at depth 9. Do you have any idea what might go
wrong?</p>
<p><br>
</p>
<p>Best,<br>
Lan</p>
</div>
</div>
<br>
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