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<p>Sebastian,<br>
<br>
Thanks. As there is some intelligence in Coin or ClpCopyOfArray the simplest is always do the copy. I have modified in stable/1.11 - does that fix problem?<br>
<br>
John<br>
<br>
<img width="16" height="16" src="cid:1__=0ABBFC07DFA4C42E8f9e8a93df938@us.ibm.com" border="0" alt="Inactive hide details for "Sebastian Theophil" ---12/22/2009 04:33:23 AM---Hi, there seems to be a bug in ClpModel::gutsOfCopy "><font color="#424282">"Sebastian Theophil" ---12/22/2009 04:33:23 AM---Hi, there seems to be a bug in ClpModel::gutsOfCopy in the stable branch:</font><br>
<br>
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<font size="2">"Sebastian Theophil" <stheophil@think-cell.com></font></td></tr>
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<font size="2"><clp@list.coin-or.org></font></td></tr>
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<font size="2">John J Forrest/Watson/IBM@IBMUS</font></td></tr>
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<font size="2" color="#5F5F5F">Date:</font></td><td width="100%"><img width="1" height="1" src="cid:2__=0ABBFC07DFA4C42E8f9e8a93df938@us.ibm.com" border="0" alt=""><br>
<font size="2">12/22/2009 04:33 AM</font></td></tr>
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<font size="2">[Clp] Bug in ClpModel::gutsOfCopy (stable branch)</font></td></tr>
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<font size="2">clp-bounces@list.coin-or.org</font></td></tr>
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<br>
<br>
<tt>Hi,<br>
<br>
there seems to be a bug in ClpModel::gutsOfCopy in the stable branch:<br>
<br>
in lines 780 and following (i.e. if trueCopy && maximumRows_<0) there is<br>
the following code:<br>
<br>
if (rhs.rowActivity_) {<br>
rowActivity_= ClpCopyOfArray(rhs.rowActivity_, numberRows_);<br>
columnActivity_=<br>
ClpCopyOfArray(rhs.columnActivity_,numberColumns_);<br>
dual_= ClpCopyOfArray(rhs.dual_, numberRows_);<br>
reducedCost_= ClpCopyOfArray(rhs.reducedCost_, numberColumns_);<br>
} else {<br>
rowActivity_=NULL;<br>
columnActivity_=NULL;<br>
dual_=NULL;<br>
reducedCost_=NULL;<br>
}<br>
<br>
which seems wrong because rhs.reducedCost_ and rhs.columnActivity_ can<br>
be non zero if rhs has > 0 columns but zero rows:<br>
<br>
ClpSimplex solver;<br>
<br>
double afLower[] = { 0.0, 0.0 };<br>
double afUpper[] = { 1.0, 1.0 };<br>
double afObj[] = { 1.0, 0.0 };<br>
solver.addColumns( 2, afLower, afUpper, afObj, NULL );<br>
<br>
ClpSimplex solver2 = solver;<br>
<br>
solver has a valid columnActivity_ array, solver2 does not. Unless<br>
further columns are added to solver2, solving solver2 should cause a<br>
crash.<br>
<br>
>From what I see, ClpModel::gutsOfCopy should either not do any checks at<br>
all and just ClpCopyOfArray every array, or it should enforce strict<br>
consistency checks like<br>
<br>
if(numberRows_>0) {<br>
rowActivity_ = copy_and_assert_not_null(rhs.rowActivity_,<br>
numberRows_)<br>
...<br>
}<br>
if(numberColumns_>0) {<br>
...<br>
}<br>
<br>
Regards,<br>
Sebastian<br>
<br>
--<br>
Sebastian Theophil . stheophil@think-cell.com<br>
Software Engineer<br>
<br>
think-cell Software GmbH . Chausseestr. 8/E . 10115 Berlin, Germany <br>
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