<br><font size=2 face="sans-serif">Clp stores slacks as -1.0 (i.e. not
really slack but row activity). There is a comment about this in
OsiClpsolverInterface but something is obviously wrong. CglGomory.cpp
uses CoinFactorization directly so does not have this problem.</font>
<br>
<br><font size=2 face="sans-serif">I will try and look at it this weekend.</font>
<br>
<br><font size=2 face="sans-serif">John Forrest</font>
<br>
<br>
<br>
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<td width=40%><font size=1 face="sans-serif"><b>Anureet Saxena <anureet@yahoo.com></b>
</font>
<br><font size=1 face="sans-serif">Sent by: coin-lpsolver-bounces@list.coin-or.org</font>
<p><font size=1 face="sans-serif">09/15/2005 05:34 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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<td>
<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">[Coin-lpsolver] problems
with BInvCol and BInvRow</font></table>
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<br><font size=3>hi,<br>
<br>
There seems to be some trouble with the <br>
OsiSimplexInterface::getBInvCol() and<br>
OsiSimplexInterface::getBInvRow() functions.<br>
<br>
In particular, constructing the basis inverse via these two functions gives<br>
different results (after transposing). Furthermore, the problem is specifically<br>
in those rows whose corresponding basic variable is a slack variable. <br>
<br>
A small example (3 rows and 5 variables) and relevent code can be downloaded<br>
from the following link:<br>
</font><font size=3 color=blue><u><br>
</u></font><a href=http://www.andrew.cmu.edu/user/anureets/tmp/ target=_blank><font size=3 color=#003399><u>http://www.andrew.cmu.edu/user/anureets/tmp/</u></font></a><font size=3><br>
File Name: BInvCol_case.tgz<br>
<br>
It will be very nice if someone could point out and/or rectify the error.</font>
<br><font size=3> </font>
<br><font size=3>On a different note, OsiSimplexInterface has a function:</font>
<br><font size=3> </font>
<br><font size=3>enableSimplexInterface(bool doingPrimal).</font>
<br><font size=3> </font>
<br><font size=3>The role of the parameter "doingPrimal" is not
adequately described in the doxygen documentation. Could someone please
give some idea as to what this parameter accomplishes. </font>
<br><font size=3><br>
<br>
regards,<br>
Anureet Saxena<br>
ACO Doctoral Student,<br>
Tepper School of Business,<br>
Carnegie Mellon University.<br>
<br>
</font>
<br><font size=3><br>
<br>
Anureet Saxena<br>
anureet@cmu.edu<br>
anureet@yahoo.com<br>
<br>
--This mail was delivered to you on 100% recyclable electrons.</font>
<p>
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