Thats explained in the documentation. Look for stop objects.
Christian -- Christian Schulte, www.ict.kth.se/~cschulte/ From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Mauricio Toro Sent: Thursday, June 19, 2008 7:59 AM To: gecode list Subject: [gecode-users] about the backtrack Hello Juan Carlos, Guido and all, Can you give some information about how to run the BAB search with a time limit? I am interesting in that too. Thanks, Mauricio 2008/6/18 Juan Carlos <[EMAIL PROTECTED]>: Exactly! is large neighborhood search. And I get your idea is very clever. thanks. Juan Carlos. On Wed, Jun 18, 2008 at 3:08 PM, Guido Tack <[EMAIL PROTECTED]> wrote: Juan Carlos wrote: Now I see, I was confused about how the backtrack works. The idea is a Local Search Method, first find a basic solution, and then make little changes till the best solution is found, here are the steps: 1)choose the best value for each variable (this value is selected by a function based on external information), once all the variables had been assigned thats a basic solution. 2) Based on that solution , re-assign some variables in order to find a better solution in a fast way. The variables that are going to be re-inserted are chosen by a function based on external information and the value is chosen by the same function of step 1. 3) repeat 2 till no solution left. By external information I mean the information of the problem instance. Now I have some ideas about how to implement this local search but they are not clear yet. Any suggestions are welcome. That sounds a lot like large neighborhood search. I'd try using a plain BAB search to find a solution, and then start a nested search, where you create a new space, assign some of the variables, and run some limited BAB (e.g. using a time limit). Once you find a better solution there, you reuse that for the original, "master" BAB search. If you don't find a better solution within the time limit, just go on in the master search. To implement this, you'll probably have to implement your own search engines or at least modifiy ours, but it should be possible. Cheers, Guido _______________________________________________ Gecode users mailing list [EMAIL PROTECTED] https://www.gecode.org/mailman/listinfo/gecode-users -- Mauricio Toro Bermudez Estudiante de Ingeniería de Sistemas Pontificia Universidad Javeriana, Colombia Stagiare à l'Ircam 1, place Igor-Stravinsky 75004 Paris, France de 2008 à 2009 -- Mauricio Toro Bermudez Estudiante de Ingeniería de Sistemas Pontificia Universidad Javeriana, Colombia Stagiare à l'Ircam 1, place Igor-Stravinsky 75004 Paris, France de 2008 à 2009
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