[Osi] a problem about osil,COUENNE,and avion2

[Gus Gassmann]

On 29 Mar 2011 at 22:04, Kipp Martin wrote:

> Hi:
> 
> > In few days ago, I tested OS-2.1.1-win32-msvc9, a binary version downloadfrom  www.coin-or.org/download/binary/OS.When I ran the command  "OSSolverService -solver couenne -osil ../data/osilFiles/avion2.osil", COIN-OS told me "Problem size before reformulation: 49 variables (0 integer), 15 constraints",and the execution stop . Why canTMt couenne solve avion2?  Has been this problem solved in stable source code version OS-2.3.0.zip ?
> >
> 
> I downloaded and tested OS-2.1.1-win32-msvc9 on my system.  If you are 
> interested in solving avion2, then
> 
> OSSolverService -solver ipopt -osil ../data/osilFiles/avion2.osil
> 
> OSSolverService -solver bonmin -osil ../data/osilFiles/avion2.osil
> 
> work fine. So I suggest you try ipopt or bonmin first. Also, I tested 
> couenne on several problems such as
> 
> OSSolverService -solver couenne -osil ../data/osilFiles/rosenbrockmod.osil
> 
> and it worked fine.
> 
> Yes, I did have problems with
> 
> 
> OSSolverService -solver couenne -osil ../data/osilFiles/avion2.osil
> 
> on my system.  I suspect this may be a Couenne problem and not an OS 
> problem. I suggest you download the Couenne project and see if you can 
> get avion2 to work directly on Couenne.

It definitely is a couenne problem. I am currently running the problem in a 
Couenne executable (without going through OS), and the program seems to 
have trouble proving optimality. It gets stuck in a loop, adding more and more 
nodes to the search tree (currently 40,000) and I suspect that it will 
eventually run out of memory or disk space and crash.

My suggestion would be to try a different test problem or, as Kipp suggested, 
use a different solver.

Cheers

gus gassmann
-------------------------------------------------------

gus gassmann          (Horand.Gassmann at dal.ca)

School of Business Administration, Dalhousie University
6100 University Avenue
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ph. (902) 494-1844
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http://myweb.dal.ca/gassmann/