<br><font size=2 face="sans-serif">Carlos,</font>
<br>
<br><font size=2 face="sans-serif">If you send me some driver which gives
flavor of what you want to do then I can have a quick look. Maybe
one small and one large model. You may be able to do a lot better
especially on the long thin models. If you add violated constraints
then you may wish to add costed slacks to make feasible and then use a
slightly modified version of Clp/examples/sprint.cpp</font>
<br>
<br><font size=2 face="sans-serif">John Forrest</font>
<br>
<br>
<br>
<br>
<br>
<table width=100%>
<tr valign=top>
<td><font size=1 color=#5f5f5f face="sans-serif">From:</font>
<td><font size=1 face="sans-serif">Carlos Eduardo Knippschild <carlos.eduardo@audaces.com.br></font>
<tr valign=top>
<td><font size=1 color=#5f5f5f face="sans-serif">To:</font>
<td><font size=1 face="sans-serif">CLP user list <clp@list.coin-or.org></font>
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<td><font size=1 color=#5f5f5f face="sans-serif">Date:</font>
<td><font size=1 face="sans-serif">02/05/2010 12:48 PM</font>
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<td><font size=1 color=#5f5f5f face="sans-serif">Subject:</font>
<td><font size=1 face="sans-serif">[Clp] Solving a lot of small and similar
LPs</font>
<tr valign=top>
<td><font size=1 color=#5f5f5f face="sans-serif">Sent by:</font>
<td><font size=1 face="sans-serif">clp-bounces@list.coin-or.org</font></table>
<br>
<hr noshade>
<br>
<br>
<br><font size=3>Hello.</font>
<br>
<br><font size=3>I'd like to know if anyone has some suggestions on how
to improve solving performance for our case, for which we're currently
using CLP.</font>
<br>
<br><font size=3>We're trying to solve tens to hundreds of thousands of dynamically generated
LPs, ranging from 30 variables by 500 constraints to a maximum of 400 variables
by 100 000 constraints. Each new generated LP is a small modification from
the one previously solved, where these modifications are always the addition
or removal of constraints (the number of variables remains always the same)
by using methods "addRow" and "deleteRows" on the existing
model.</font>
<br>
<br><font size=3>I've already played a little bit with some of the parameters
I've found, and so far I discovered that by disabling presolve and scaling
we improve a little our times.</font>
<br>
<br><font size=3>So, does anyone have any ideas on how to get even better
results? Are there better ways of keeping this ever changing model? What
other parameters should I play with?</font>
<br>
<br><font size=3>Or even, if another project from COIN-OR would be more
suitable for our case. Recently I read about DyLP: would it be an interesting
option for this case?</font>
<br>
<br>
<br><font size=3>Thank you for your time! Any help will be much appreciated.</font>
<br>
<br><font size=3>Regards,</font>
<br><font size=3>--<br>
Carlos E. Knippschild</font><tt><font size=2>_______________________________________________<br>
Clp mailing list<br>
Clp@list.coin-or.org<br>
</font></tt><a href="http://list.coin-or.org/mailman/listinfo/clp"><tt><font size=2>http://list.coin-or.org/mailman/listinfo/clp</font></tt></a><tt><font size=2><br>
</font></tt>
<br>
<br>