<br><font size=2 face="sans-serif">Kish,</font>
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<br><font size=2 face="sans-serif">Yes please send program - I do want
to find the bug but can't reproduce on my computer.</font>
<br>
<br><font size=2 face="sans-serif">John Forrest</font>
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<td width=40%><font size=1 face="sans-serif"><b>Kish Shen <ks15@icparc.ic.ac.uk></b>
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<br><font size=1 face="sans-serif">Sent by: coin-lpsolver-bounces@list.coin-or.org</font>
<p><font size=1 face="sans-serif">08/15/2005 04:40 PM</font>
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<div align=right><font size=1 face="sans-serif">To</font></div>
<td valign=top><font size=1 face="sans-serif">coin-lpsolver@list.coin-or.org</font>
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<div align=right><font size=1 face="sans-serif">cc</font></div>
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<div align=right><font size=1 face="sans-serif">Subject</font></div>
<td valign=top><font size=1 face="sans-serif">Re: [Coin-lpsolver] checkClear()
in createRim() and NDEBUG compilation
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<br><font size=2><tt>Hi John,<br>
<br>
John Forrest <jjforre@us.ibm.com> wrote:<br>
<br>
>If it fails it is a serious bug. The checkClear is expensive
so should not be<br>
>in for production work. Try if a clear() before gets rid of error
and if so<br>
<br>
I am also running into this assert failure in several problems, when I
use Clp<br>
in conjunction with Cbc:<br>
<br>
Cbc0015I Node 40 Obj 931.231 Unsat 77 depth 26<br>
Coin0507I Presolve determined that the problem was infeasible with tolerance
of 1e-08<br>
eclipse.exe: ClpSimplex.cpp:3367: bool ClpSimplex::createRim(int, bool,
int): Assertion `rowArray_[iRow]->capacity()==length' failed.<br>
Signal 6<br>
<br>
I have been trying various MIP problems with Osi/Cbc/Clp combination, and<br>
out of 20 problem instances, 4 problems aborted with assert failures, and<br>
at least 2 of these aborted at the above capacity()==length. I don't know<br>
if the problems are due to Cbc or Clp, but the assert failures are in Cbc.<br>
<br>
We are using Cbc/Clp as a MP solver for our own ECLiPSe system, and the<br>
problem is loaded into a CoinPackedMatrix in a column-wise fashion. I have<br>
managed to log the calls to Osi from our system, and I have been able to<br>
compile these logged calls as a C++ program, and running this program<br>
reproduce the problem above. If you are willing to look at this problem
(I<br>
am afraid I don't know enough about Simplex or Cbc/Clp to look at this<br>
problem myself :-(), I can send you this program.<br>
<br>
[the logged program is quite large, as it records all the calls to setting<br>
the matrix coefficients, but it gzips down to about 42K.]<br>
<br>
Yours sincerely,<br>
<br>
Kish Shen<br>
IC-Parc<br>
Imperial College London<br>
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