<html>
<head>
<meta content="text/html; charset=windows-1252"
http-equiv="Content-Type">
</head>
<body bgcolor="#FFFFFF" text="#000000">
<div class="moz-cite-prefix">Hi James,<br>
<br>
if you just want to do this with relpscost, you could call
SCIPexecRelpscostBranching() in the ENFOLP callback of your
constraint handler and only pass the subset of variables as
branching candidates.<br>
<br>
Best,<br>
Gerald<br>
<br>
On 15.03.2016 12:18, James Cussens wrote:<br>
</div>
<blockquote
cite="mid:CALQgqO27+Mkx8VtqHeou6uKVrEh9TT9_m-noUg0haEzyqPSntA@mail.gmail.com"
type="cite">
<div dir="ltr">Dear SCIPers,
<div><br>
</div>
<div>I would like to implement a branching strategy where at
each node only a subset of variables are considered as
branching candidates. Which subset this is will depend on the
node in question (specifically which variables are already
fixed by the time we get to that node).</div>
<div><br>
</div>
<div>It seems to me that a potentially easy way of doing this is
to update the branching priorities of variables before the
branching decision is made (I want the current branching rule
(eg relpscost) to choose which of my candidates to branch on.)</div>
<div><br>
</div>
<div>But I'm not sure </div>
<div>1) if this is a reasonable way of implementing what I want
to happen, and</div>
<div>2) if it is, where in my code to effect the branching
priority updating.</div>
<div><br>
</div>
<div>I have a constraint handler (it's a "global" one - there is
always a constraint which is not satisfied until the entire
problem is solved). One option would seem to be to update the
branching priorities in its ENFOLP callback and declare
SCIP_INFEASIBLE. But this seems a bit of hack.</div>
<div><br>
</div>
<div>Another possibility is to write an event handler, so that
branching priorities get updated when other variables get
fixed.</div>
<div><br>
</div>
<div>Any advice / ideas?</div>
<div><br>
</div>
<div>James</div>
<div>
<div><br>
</div>
-- <br>
<div class="gmail_signature">James Cussens<br>
Dept of Computer Science &<br>
York Centre for Complex Systems Analysis<br>
Room 326, The Hub, Deramore Lane Tel +44
(0)1904 325371<br>
University of York
Fax +44 (0)1904 500159<br>
York YO10 5GE, UK <a
moz-do-not-send="true"
href="http://www.cs.york.ac.uk/%7Ejc" target="_blank"><a class="moz-txt-link-freetext" href="http://www.cs.york.ac.uk/~jc">http://www.cs.york.ac.uk/~jc</a></a><br>
<a moz-do-not-send="true"
href="http://www.york.ac.uk/docs/disclaimer/email.htm"
target="_blank">http://www.york.ac.uk/docs/disclaimer/email.htm</a></div>
</div>
</div>
<br>
<fieldset class="mimeAttachmentHeader"></fieldset>
<br>
<pre wrap="">_______________________________________________
Scip mailing list
<a class="moz-txt-link-abbreviated" href="mailto:Scip@zib.de">Scip@zib.de</a>
<a class="moz-txt-link-freetext" href="http://listserv.zib.de/mailman/listinfo/scip">http://listserv.zib.de/mailman/listinfo/scip</a>
</pre>
</blockquote>
<br>
</body>
</html>