[Couenne] Informations about Gap and Couenne

[Pietro Belotti]

Dear Pierre-Hakim,

in the option file couenne.opt, add the following line:

bb_log_level 1

Then, if Couenne did not find a global optimum, the output should contain 
a line like the following:

Cbc0005I Partial search - best objective -3500 (best possible -6960.9), 
took 321 iterations and 0 nodes (1.93 seconds)

which gives you the upper bound (-3500) and a lower bound (-6960.9), that 
allows to compute a gap. If instead Couenne terminates with a global 
optimum, you will see a line such as the following

Cbc0001I Search completed - best objective -7.487442645409277, took 162 
iterations and 10 nodes (0.09 seconds)

Hope this helps. Please direct all of your future questions to the Couenne 
mailing list, couenne at list.coin-or.org

Regards,
Pietro

--
Pietro Belotti
Dept. of Mathematical Sciences
Clemson University
email: pbelott at clemson.edu
phone: 864-656-6765
www:   myweb.clemson.edu/~pbelott

On Wed, 22 Sep 2010, BOUGATTAYA Pierre-Hakim wrote:

> Dear Mister Belotti,
>
> I'm working on differents problems, and I use Couenne to solve them.
> I use Couenne on Neos solver and I want to know if it is possible to have
> the Gap (lower bound & upper bound) when Couenne sends me his resolution
> report.
> I think if it's not possible, I will have to install Couenne on my computer.
>
> With anticipated thanks for your help,
> best regards
>
> Pierre-Hakim Bougattaya
>