[Cbc] [CBC] Time limit in Cbc

[John J Forrest]

Mathieu,

Cbc does check time after each round of cuts and a solve.  When I played
around with a time limit,  I found that it was still going into heuristics
at root node.  This could be the problem, especially as the time limit
check in an expensive heuristic (i.e. one that does a small branch and
bound) checks the time it has spent against smaller of its time limit and
overall time limit.  It should be checking total time spent.

Will put in a few more checks and fix time check at weekend - see if that
helps.

Solution etc looks OK to me.

John


                                                                                             
  From:       Mathieu Lacroix <lacroix at isima.fr>                                             
                                                                                             
  To:         cbc at list.coin-or.org                                                           
                                                                                             
  Date:       08/19/2009 05:43 AM                                                            
                                                                                             
  Subject:    [Cbc] [CBC] Time limit in Cbc                                                  
                                                                                             
  Sent by:    cbc-bounces at list.coin-or.org                                                   
                                                                                             





Hello everybody,

It is possible to give a time limit to Cbc. However, it seems that cbc
checks whether the time limit is reached only before branching. As in my
problem, the time limit is reached before branching (due to cut
generation at the root node), is it possible to force cbc to check the
time limit after each cut generation? And if the time limit is reached,
how to stop cbc without loosing all the informations (upper bound, lower
bound and best solution found if any)?

Thanks you for any reply,
Cheers,

Mathieu LACROIX

--
Mathieu LACROIX
lacroix at lamsade.dauphine.fr
Laboratoire LAMSADE
Université Paris-Dauphine
Place du Maréchal de Lattre de Tassigny
75775 Paris cedex 16 - France
Tel: +33 (0)1 44 05 48 53
URL: http://epoc.isima.fr/~lacroix/



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