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Dear Albert,<br>
<br>
changing the upper bound to 0 to enforce your decision is correct.
However, your consactive method should only mark the constraint to
be repropagated; afterwards, propagation will be called where you
should adjust the bounds. Since the bound is only changed at the
current node, SCIP will automatically undo this when the current
subtree is left and re-install the bound when it is re-entered. In
the latter case, you thus only need to propagate variables added in
the meantime.<br>
<br>
For more details, see
<a class="moz-txt-link-freetext" href="https://scip.zib.de/doc-6.0.2/html/FAQ.php#pricerandnodedata">https://scip.zib.de/doc-6.0.2/html/FAQ.php#pricerandnodedata</a> or have
a look at the binpacking example.<br>
<br>
Best,<br>
Gerald<br>
<br>
<div class="moz-cite-prefix">Am 09.01.20 um 10:45 schrieb
Schrotenboer, Albert:<br>
</div>
<blockquote type="cite"
cite="mid:CALr_SJm58B7cRt0ECRU+a1rUfx0sHpSK1kyC1YAecke3uSn__w@mail.gmail.com">
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<div class="gmail_default"
style="font-family:arial,helvetica,sans-serif">Dear SCIP
Community,</div>
<div class="gmail_default"
style="font-family:arial,helvetica,sans-serif"><br>
</div>
<div class="gmail_default"
style="font-family:arial,helvetica,sans-serif">I am solving a
basic VRP with branch & price, and have a question
regarding a branching rule I've implemented (Actually, I
forgot how to do it...) I branch on x_{ij} arcs, which I
identify with my branchrule object. To handle this information
down the b&b tree, I use a constraint handler with the
following virtual methods implemented:<br>
</div>
<div class="gmail_default"
style="font-family:arial,helvetica,sans-serif"><br>
</div>
<div class="gmail_default"
style="font-family:arial,helvetica,sans-serif">SCIP_DECL_CONSTRANS(ObjConshdlrOwn::scip_trans)
<br>
</div>
<div><span class="gmail_default"
style="font-family:arial,helvetica,sans-serif"> To
transform the info, nothing special</span></div>
<div><span class="gmail_default"
style="font-family:arial,helvetica,sans-serif"></span><span
class="gmail_default"
style="font-family:arial,helvetica,sans-serif"></span></div>
<div><span class="gmail_default"
style="font-family:arial,helvetica,sans-serif">SCIP_DECL_CONSACTIVE(ObjConshdlrOwn::scip_active)</span></div>
<div><span class="gmail_default"
style="font-family:arial,helvetica,sans-serif"> Here I
search which of my generated routes should be fixed to zero
corresponding to my branching information. (I also do the
appropriate adaptations in my pricing based on the
branching). I fix my variables by the following routines:</span></div>
<div><span class="gmail_default"
style="font-family:arial,helvetica,sans-serif"><br>
</span></div>
<div><span class="gmail_default"
style="font-family:arial,helvetica,sans-serif">if
(SCIPvarGetUbLocal(var) > 0.01)<br>
SCIP_CALL(SCIPchgVarUb(scip,
(*d_varConsInfo).v_path[r].d_var, 0.0) ); <br>
</span></div>
<div><span class="gmail_default"
style="font-family:arial,helvetica,sans-serif"><br>
</span></div>
<div><span class="gmail_default"
style="font-family:arial,helvetica,sans-serif">This all
works nicely (when I do not run in debug mode). When I run
in Debug mode, however, an assert is collapsing when SCIP
alters the path of the tree (when it backtracks a few
nodes), saying that:</span></div>
<div><span class="gmail_default"
style="font-family:arial,helvetica,sans-serif">JRP:
src/scip/tree.c:1803: SCIPnodeAddBoundinfer: Assertion
`(SCIP_NODETYPE)node->nodetype == SCIP_NODETYPE_FOCUSNODE
|| (SCIP_NODETYPE)node->nodetype ==
SCIP_NODETYPE_PROBINGNODE ||
(SCIP_NODETYPE)node->nodetype == SCIP_NODETYPE_CHILD ||
(SCIP_NODETYPE)node->nodetype ==
SCIP_NODETYPE_REFOCUSNODE || node->depth == 0' failed.<br>
</span></div>
<div><span class="gmail_default"
style="font-family:arial,helvetica,sans-serif"><br>
</span></div>
<div><span class="gmail_default"
style="font-family:arial,helvetica,sans-serif">My question
is, therefore, the following: Is changing the UB to enforce
variables to 0 the correct way to go? In addition, am I
required to implement the deactive virtual method as well,
to change the upper bounds back to what they were? <br>
</span></div>
<div><span class="gmail_default"
style="font-family:arial,helvetica,sans-serif"><br>
</span></div>
<div><span class="gmail_default"
style="font-family:arial,helvetica,sans-serif">Kind regards,</span></div>
<div><span class="gmail_default"
style="font-family:arial,helvetica,sans-serif">Albert<br>
</span></div>
<div><span class="gmail_default"
style="font-family:arial,helvetica,sans-serif"><br>
</span></div>
<div>
<div>-- <br>
<div dir="ltr" class="gmail_signature"
data-smartmail="gmail_signature">
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<div
style="color:rgb(0,0,0);font-size:10pt;letter-spacing:normal;line-height:12pt;margin-bottom:0px;margin-top:0px">
<p class="MsoNormal"><span
style="color:rgb(102,102,102)">Albert
Schrotenboer</span></p>
<p class="MsoNormal"><span
style="color:rgb(102,102,102)">Postdoctoral
Researcher<br>
</span></p>
<p class="MsoNormal"><span
style="color:rgb(102,102,102)">Faculty
of Economics and Business</span></p>
<p class="MsoNormal"><span
style="color:rgb(102,102,102)"></span><font
color="rgb(34, 34, 34)"><span
style="color:rgb(102,102,102)">University
of Groningen</span></font><font
color="rgb(34, 34, 34)"><span
style="color:rgb(102,102,102)"><br>
</span></font></p>
<p class="MsoNormal"><font
color="rgb(34, 34, 34)"><span
style="color:rgb(102,102,102)">P.O.
Box 800, 9700 AV Groningen</span>
</font></p>
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