Hi, please have a look at some of the examples that come with Gecode, there you find how branch (which in turn creates simple variable/value branchings) is used with different heuristics. There are two examples (black-hole.cc and queen-armies.cc) that have simple custom branchings which might give you some additional hints.
The current trunk has more support for predefined branchings (randomized, tie-breaking, etc) that should make it into Gecode 3.* (scheduled to be released around Sep/Oct). All the best Christian -- Christian Schulte, www.ict.kth.se/~cschulte/ -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Oliver Kullmann Sent: Friday, June 06, 2008 9:55 PM To: [EMAIL PROTECTED] Subject: [gecode-users] implementing branching heuristics Hello, based on my general theory of branching heuristics, I would like to take some standard backtracking CSP solvers, where I can just replace the variable ordering heuristics (responsible for choosing the branching variable), and there I would like to plug-in my generic heuristics instead --- I expect relevant performance gains. The whole theory has been developed in the context of SAT, but it is applicable for any width of branchings (not just binary branchings), and this is actually one of its strengths. If somebody wants to read about it, please have a look at report #7 at http://www.swan.ac.uk/compsci/research/reports/2008/index.html It should be fairly easy to apply my generic heuristics. I looked a bit at Minion, but this looks too much black-box to me. I guess in principle with gecode it should be doable. But the documentation is rather terse, and I also couldn't find some standard solvers, where I just would replace some functions regarding the heuristics. Perhaps somebody can help me here? Or, if somebody is interested, we could have a collaboration. I actually expect a "quick victory", i.e., it should be quickly implementable, and it should yield some nice improvements under fairly general circumstances. So, I hope somebody is interest in a quick paper which will revolutionise CSP ;-) Actually, I think it will be interesting. Oliver P.S. Another field for possible collaboration would be library development: I am developing the OKlibrary (http://www.ok-sat-library.org), a generative library for generalised SAT solving. In principle the OKlibrary covers also CSP, but I'm yet "pre-alpha" :-(. P.S.P.S. I noticed in the documentation of gecode that "branchings" etc. are used in a from my point of view somewhat non-standard sense. I'm using "branching" etc. as used by the SAT community and as explained in my article, but this seems to me also compatible to the notions used in the Handbook of Constraint Satisfaction. -- Dr. Oliver Kullmann Computer Science Department Swansea University Faraday Building, Singleton Park Swansea SA2 8PP, UK http://cs.swan.ac.uk/~csoliver/ _______________________________________________ Gecode users mailing list [EMAIL PROTECTED] https://www.gecode.org/mailman/listinfo/gecode-users _______________________________________________ Gecode users mailing list [EMAIL PROTECTED] https://www.gecode.org/mailman/listinfo/gecode-users
