<br><font size=2 face="sans-serif">Renaud,</font>
<br>
<br><font size=2 face="sans-serif">I have modified OsiClpSolverInterface
in trunk version so that you can pass in options which will be used in
initialSolve. These options are from ClpSolve and so are more general
than just barrier, but I thought it could be useful. So you can play
around using stand-alone "clp" to see which options work and
then transfer code to your driver. There is a sample program "barrier.cpp"
in Cbc/examples (I know that it is nothing to do with Cbc, but there is
no Osi/examples directory). </font>
<br>
<br><font size=2 face="sans-serif">However the standard barrier in Clp
is not good if you do not use a third-party ordering and factorization
code. One from the University of Florida is suitable. If I
get time next week I will try and make it easier to use with the svn version
of Coin - It was working in the old cvs version. This what you have
to do - add to your configure</font>
<br>
<br><font size=2 face="sans-serif">ADD_CXXFLAGS="-DUFL_BARRIER -I(directory
with amd.h) -L(directory with libamd.a) -lamd</font>
<br>
<br><font size=2 face="sans-serif">You will get mild warnings that -lamd
is being ignored for compilation.</font>
<br>
<br><font size=2 face="sans-serif">Then play with clp using -chol UFL</font>
<br>
<br><font size=2 face="sans-serif">Barrier.cpp will also work but you have
to add an extra -lamd in Makefile (before -lm). As I said I will
try and make prettier next week.</font>
<br>
<br><font size=2 face="sans-serif">You might also try the dualCuts.cpp
example in Clp/examples which might work well with a problem of the shape
you describe. If you then want to convert to Osi the function calls
would be very similar.</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>"Renaud Lepere"
<renaud.lepere@alma.fr></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">10/16/2006 06:15 AM</font>
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<div align=center><font size=1 face="sans-serif">Please respond to<br>
Discussions about open source software for Operations Research
<coin-discuss@list.coin-or.org></font></div></table>
<br>
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<td>
<div align=right><font size=1 face="sans-serif">To</font></div>
<td><font size=1 face="sans-serif"><coin-discuss@list.coin-or.org></font>
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<td>
<div align=right><font size=1 face="sans-serif">cc</font></div>
<td>
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<td>
<div align=right><font size=1 face="sans-serif">Subject</font></div>
<td><font size=1 face="sans-serif">[Coin-discuss] using CLP barrier with
OSI</font></table>
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<br></table>
<br>
<br>
<br><tt><font size=2>I am using linear programing and COIN-OR (osi and
clp) to optimize<br>
nesting problems. I have quite a lot of variables (up to 1000) <br>
representing positions of nested parts and approximatly the same<br>
order of magnitude of constaints (up to 5000). Those constraints<br>
corresponds to the non-overlapping condition between nested parts.<br>
<br>
I would like to solve those problems as fast as possible. I would like
<br>
to know if a barrier algorihtm can speed up my computation time ; and<br>
if it is possible to use the barrier algorithm included in CLP with OSI<br>
?<br>
<br>
Thanks<br>
<br>
Renaud<br>
<br>
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