<br><font size=2 face="sans-serif">Dr. Forrest, thanks for your response.</font>
<br>
<br><font size=2 face="sans-serif">The test application, which is provided
with Cbc, enables preprocessing by default, so we were indeed using it.
(See Cbc/Test/CbcMain.cpp, in the function main.)</font>
<br>
<br><font size=2 face="sans-serif">I turned it off and the results look
much better: the results from getColSolution and bestSolution are now very
similar and adhere to the constraints. The bestSolution vector has
some ignorable tiny deviations from 0 in some variable; the getColSolution
vector seems to lack these. Do you have any further advice or clarification?
Without it, I think we will go back to getColSolution for now.</font>
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<td width=40%><font size=1 face="sans-serif"><b>John J Forrest <jjforre@us.ibm.com></b>
</font>
<br><font size=1 face="sans-serif">Sent by: coin-discuss-bounces@list.coin-or.org</font>
<p><font size=1 face="sans-serif">01/18/2006 08:28 PM</font>
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<td valign=top><font size=1 face="sans-serif">Re: [Coin-discuss] Extracting
the best solution in Cbc.</font></table>
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<br><font size=2 face="sans-serif"><br>
Were you using pre-processing? If not it definitely should have worked.
If you are then there is now a cleaner way of doing pre-processing
using CbcStrategy - see Samples/repeat.cpp to give you a clue. If
you that fails it can you send me something to help debug - I did some
tests and it seemed Ok.</font><font size=3> <br>
</font><font size=2 face="sans-serif"><br>
John Forrest</font><font size=3> <br>
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<td width=64%><font size=1 face="sans-serif"><b>acw@ascent.com</b> <br>
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<p><font size=1 face="sans-serif">01/17/2006 05:07 PM</font><font size=3>
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<td><font size=1 face="sans-serif">[Coin-discuss] Extracting the best solution
in Cbc.</font></table>
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(Apologies if this message is a duplication; this message bounced the first
time because I had not properly joined the mailing list.)</font><font size=3>
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__________________</font><font size=3> </font><font size=2 face="sans-serif"><br>
<br>
We are using a COIN/Cbc application that we created by making slight modifications
to the test example provided with Cbc.</font><font size=3> </font><font size=2 face="sans-serif"><br>
<br>
What is the recommended way to extract the best feasible integer solution?
The documentation says to use CbcModel::bestSolution. We tried
this, and got bad (infeasible) results. The example application (in
its implementation of the SOLUTION command) uses CbcModel::getColSolution,
which is not documented. The documentation does mention OsiSolverInterface::getColSolution,
but this is deprecated (with somewhat ambiguous language) in favor of CbcModel::bestSolution.</font><font size=3>
</font><font size=2 face="sans-serif"><br>
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We decided to mimic the example, and tried the undocumented CbcModel::getColSolution.
This worked nicely with instances that ran to completion, but when
we added a time limit (with CbcModel::setMaximumSeconds) the reported solution
was again infeasible. (CbcModel::branchAndBound did report finding
several integer solutions in the running time available.)</font><font size=3>
</font><font size=2 face="sans-serif"><br>
<br>
Thank you for your assistance. We are finding Cbc, overall, quite
easy to work with and adapt to our needs.</font><font size=2><tt>_______________________________________________<br>
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