<font face="arial,helvetica,sans-serif">Did more experiments to see when this bug occurs.<br><br>To turn off all heuristics and cuts it makes it happens faster.<br><br>This is an instance <a href="http://www.decom.ufop.br/haroldo/files/sprint_hidden06.lp.gz">http://www.decom.ufop.br/haroldo/files/sprint_hidden06.lp.gz</a><br>
which is quickly solved by CPLEX and has optimal objective function value 130.<br><br>CBC crashes at this point:<br><br><font style="font-family: courier new,monospace; color: rgb(0, 0, 102);" size="2">Cbc0010I After 1700 nodes, 656 on tree, 249 best solution, best possible 99.390873 (139.08 seconds)<br>
cbc: CbcBranchDynamic.cpp:551: virtual int CbcBranchDynamicDecision::betterBranch(CbcBranchingObject*, CbcBranchingObject*, double, int, double, int): Assertion `distance >= 0.0' failed<br></font><br><br><br><br><br>
<br><br></font><br><div class="gmail_quote">On Wed, Aug 24, 2011 at 5:43 PM, Haroldo Santos <span dir="ltr"><<a href="mailto:haroldo.santos@gmail.com">haroldo.santos@gmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">
<font face="arial,helvetica,sans-serif">Dear Forrest/CBC Developers,<br><br>There is this assertion failing in :<br><span style="font-family:courier new,monospace;color:rgb(0, 0, 102)">CbcBranchDynamic.cpp:551: virtual int CbcBranchDynamicDecision::betterBranch(CbcBranchingObject*, CbcBranchingObject*, double, int, double, int): Assertion `distance >= 0.0' failed.</span><br style="font-family:courier new,monospace;color:rgb(0, 0, 102)">
<br>when I'm solving this MIP: <a href="http://www.decom.ufop.br/haroldo/files/sprint_hidden04.lp.gz" target="_blank">http://www.decom.ufop.br/haroldo/files/sprint_hidden04.lp.gz</a> <br><br>I did some debug and discover that this fails because at a given point of the search the distance is -0.415667 .<br>
<br clear="all"></font><span style="color:rgb(0, 0, 102)">Cbc0010I After 10000 nodes, 4845 on tree, 180 best solution, best possible 142.25 (1909.96 seconds)</span><br style="color:rgb(0, 0, 102)"><span style="color:rgb(0, 0, 102)">Cbc0010I After 10100 nodes, 4849 on tree, 180 best solution, best possible 142.25 (1919.14 seconds)</span><br>
<br>Tested in Linux with CBC 2.7 stable, default compilation options and no ThirdParty software included.<br style="color:rgb(0, 0, 102)"><br><span style="font-family:arial,helvetica,sans-serif">The stack trace at this point is:</span><br style="font-family:arial,helvetica,sans-serif">
<span style="font-family:courier new,monospace;color:rgb(0, 0, 102)"></span><span style="font-family:courier new,monospace;color:rgb(0, 0, 102)">#0 0x00007ffff779c5cb in CbcBranchDynamicDecision::betterBranch (this=0xb3eee10, thisOne=</span><br style="font-family:courier new,monospace;color:rgb(0, 0, 102)">
<span style="font-family:courier new,monospace;color:rgb(0, 0, 102)"> 0x12d60060, changeUp=0, numInfUp=205, changeDown=0, numInfDown=211) at CbcBranchDynamic.cpp:555</span><br style="font-family:courier new,monospace;color:rgb(0, 0, 102)">
<span style="font-family:courier new,monospace;color:rgb(0, 0, 102)">#1 0x00007ffff784bf40 in CbcNode::chooseDynamicBranch (this=0x12d9a290, model=0x60dcd0, </span><br style="font-family:courier new,monospace;color:rgb(0, 0, 102)">
<span style="font-family:courier new,monospace;color:rgb(0, 0, 102)"> lastNode=0x12aa7510, numberPassesLeft=4) at CbcNode.cpp:3178</span><br style="font-family:courier new,monospace;color:rgb(0, 0, 102)"><span style="font-family:courier new,monospace;color:rgb(0, 0, 102)">#2 0x00007ffff783521c in CbcModel::chooseBranch (this=0x60dcd0, newNode=@0x7fffffff53a0, </span><br style="font-family:courier new,monospace;color:rgb(0, 0, 102)">
<span style="font-family:courier new,monospace;color:rgb(0, 0, 102)"> numberPassesLeft=5, oldNode=0x12aa7510, cuts=..., resolved=@0x7fffffff4d18, lastws=0x12e21f40, </span><br style="font-family:courier new,monospace;color:rgb(0, 0, 102)">
<span style="font-family:courier new,monospace;color:rgb(0, 0, 102)"> lowerBefore=0x12ac54b0, upperBefore=0x1396c2e0, branches=@0x7fffffff4b08) at CbcModel.cpp:12642</span><br style="font-family:courier new,monospace;color:rgb(0, 0, 102)">
<span style="font-family:courier new,monospace;color:rgb(0, 0, 102)">#3 0x00007ffff783b052 in CbcModel::doOneNode (this=0x60dcd0, baseModel=0x60dcd0, </span><br style="font-family:courier new,monospace;color:rgb(0, 0, 102)">
<span style="font-family:courier new,monospace;color:rgb(0, 0, 102)"> node=@0x7fffffff5298, newNode=@0x7fffffff53a0) at CbcModel.cpp:14299</span><br style="font-family:courier new,monospace;color:rgb(0, 0, 102)">
<span style="font-family:courier new,monospace;color:rgb(0, 0, 102)">#4 0x00007ffff78108f5 in CbcModel::branchAndBound (this=0x60dcd0, doStatistics=0)</span><br style="font-family:courier new,monospace;color:rgb(0, 0, 102)">
<span style="font-family:courier new,monospace;color:rgb(0, 0, 102)"> at CbcModel.cpp:3797</span><br style="font-family:courier new,monospace;color:rgb(0, 0, 102)"><span style="font-family:courier new,monospace;color:rgb(0, 0, 102)">#5 0x00007ffff7b7be8b in CbcMain1 (argc=11, argv=0x7fffffffdef8, model=..., </span><br style="font-family:courier new,monospace;color:rgb(0, 0, 102)">
<span style="font-family:courier new,monospace;color:rgb(0, 0, 102)"> callBack=0x7ffff7b67569 <dummyCallBack(CbcModel*, int)>) at CbcSolver.cpp:5589</span><br style="font-family:courier new,monospace;color:rgb(0, 0, 102)">
<span style="font-family:courier new,monospace;color:rgb(0, 0, 102)">#6 0x00007ffff7b67bb5 in CbcMain1 (argc=11, argv=0x7fffffffdef8, model=...) at CbcSolver.cpp:1111</span><br style="font-family:courier new,monospace;color:rgb(0, 0, 102)">
<span style="font-family:courier new,monospace;color:rgb(0, 0, 102)">#7 0x0000000000400f47 in main (argc=11, argv=0x7fffffffdef8) at CoinSolve.cpp:336</span><br style="font-family:courier new,monospace;color:rgb(0, 0, 102)">
<br>Cheers, <br><br>Haroldo<br style="color:rgb(0, 0, 102)"><br>-- <br>=============================================================<br>Haroldo Gambini Santos<br>Computing Department - Universidade Federal de Ouro Preto - UFOP<br>
email: haroldo [at ] <a href="http://iceb.ufop.br" target="_blank">iceb.ufop.br</a><br>home/research page: <a href="http://www.decom.ufop.br/haroldo/" target="_blank">www.decom.ufop.br/haroldo/</a><br> <br>"Computer science is no more about computers than astronomy <br>
is about telescopes." Edsger Dijkstra<br> <br>
</blockquote></div><br><br clear="all"><br>-- <br>=============================================================<br>Haroldo Gambini Santos<br>Computing Department - Universidade Federal de Ouro Preto - UFOP<br>email: haroldo [at ] <a href="http://iceb.ufop.br" target="_blank">iceb.ufop.br</a><br>
home/research page: <a href="http://www.decom.ufop.br/haroldo/" target="_blank">www.decom.ufop.br/haroldo/</a><br> <br>"Computer science is no more about computers than astronomy <br>is about telescopes." Edsger Dijkstra<br>
<br>