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<DIV>Hi All,</DIV>
<DIV> </DIV>
<DIV>
<P style="MARGIN: 0cm 0cm 0pt" class=MsoNormal><?xml:namespace prefix = o ns =
"urn:schemas-microsoft-com:office:office" /><o:p><FONT color=#ffffff
face="Times New Roman"> </FONT></o:p></P>
<P style="MARGIN: 0cm 0cm 0pt" class=MsoNormal><SPAN
style="FONT-FAMILY: 'Times New Roman','serif'; COLOR: windowtext; FONT-SIZE: 12pt"><FONT
face="Times New Roman">In Microsoft Visual Studio, the strict weak ordering of
nodes in a heap must be preserved i.e. if node x is deemed to be "less"
the node y, then y cannot be evacuated to be "less" than x by a predicate
or comparison function.</FONT></SPAN></P>
<P style="MARGIN: 0cm 0cm 0pt" class=MsoNormal><SPAN
style="FONT-FAMILY: 'Times New Roman','serif'; COLOR: windowtext; FONT-SIZE: 12pt"><FONT
face="Times New Roman"><o:p></o:p></FONT></SPAN> </P></DIV>
<DIV>Thanks.</DIV>
<DIV> </DIV>
<DIV>Gabrielle</DIV>
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style="BORDER-LEFT: #000000 2px solid; PADDING-LEFT: 5px; PADDING-RIGHT: 0px; MARGIN-LEFT: 5px; MARGIN-RIGHT: 0px">
<DIV style="FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV
style="FONT: 10pt arial; BACKGROUND: #e4e4e4; font-color: black"><B>From:</B>
<A title=lou@cs.sfu.ca href="mailto:lou@cs.sfu.ca">Lou Hafer</A> </DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A title=cbc@list.coin-or.org
href="mailto:cbc@list.coin-or.org">cbc@list.coin-or.org</A> </DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Wednesday, November 14, 2012 8:18
AM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> Re: [Cbc] Problem in
CbcCompareUser/invalid heap</DIV>
<DIV><BR></DIV>Folks,<BR><BR> If it's windows, this is
a long-standing issue. Debug builds in <BR>Visual Studio were unusable because
the VS heap implementation checks <BR>for violations of the heap conditions in
debug builds. Cbc did not <BR>properly rebuild the heap after changing the
evaluation function. I <BR>fixed this in r1506 because I needed to work with a
windows debug build <BR>but quite possibly it's broken
again.<BR><BR> The key point is that the heap must be
rebuilt when the evaluation <BR>function changes. Otherwise it's a bomb
waiting to go off.<BR><BR> John's observation about
using drand as the return value is <BR>interesting. Begs the question of
whether the overhead of maintaining <BR>the heap is really worth
it.<BR><BR>
Lou<BR><BR><BR><BR>On 14/11/12 12:43 AM, John Forrest wrote:<BR>>
Haroldo,<BR>><BR>> Using which compiler do you have problems with
CbcCompareDefault - or is<BR>> it with CbcCompareUser?<BR>><BR>> If
it is gcc then I am totally mystified as I changed CbcCompareDefault<BR>>
to do<BR>><BR>> return
(drand48()<0.5);<BR>><BR>> and my runs were fine (not even much
slower!).<BR>> 1506<BR>> So is just with Windows or
Intel?<BR>><BR>> John
Forrest<BR><BR>_______________________________________________<BR>Cbc mailing
list<BR><A href="mailto:Cbc@list.coin-or.org">Cbc@list.coin-or.org</A><BR><A
href="http://list.coin-or.org/mailman/listinfo/cbc">http://list.coin-or.org/mailman/listinfo/cbc</A></BLOCKQUOTE></BODY></HTML>