Philipp Marcus wrote: > Hi, > > thanks for all your helpful replies. > > At 30.04.2010 03:48, Joachim Schimpf wrote: >> I really have to apologize to Marco, because he gave me his code years >> ago, and I never got round to update it for IC and to put it into the >> ECLiPSe distribution... >> > > are you still planing to port Marco's code to IC and if so, can you give > an estimate until when it would be finished? His code would be exactly > what I'd need but at the moment I don't feel experienced enough to port > it from FD to IC on my own. Dear Joachim and Philipp, there is no need for Joachim to apologize: I know he is very busy and works hard to make ECLiPSe the excellent platform it is now. I think the code by Joachim is correct; I remember a talk by Filippo Focacci at CPAIOR 02 on a similar method. Concerning the Pareto front, I must give two warnings to Philipp: - First, computing the Pareto front is VERY expensive: it will take a long time, and it will likely produce an exponentially long list of solutions. - Second, as for all NP-hard problems, there is no solution that is always the best. As for one-function minimization, one can use the 'continue' or the 'restart' strategy, and each works well in some cases. The method I proposed in ECAI02 was using the 'continue' strategy. However, the 'restart' strategy is probably easier to implement. Try the following example: run:- [A,B]::0..10, A+B #> 10, F1 #= A, F2 #= B, bb_min( ( repeat, ( bb_min( labeling([A,B]) ,F2,bb_options{strategy:restart}) -> write('found solution with cost '), writeln([F1,F2]) ; ! ) ) ,F1,bb_options{strategy:restart}). Of course, if you want a list of solutions you have to store them in some unbacktrackable data structure. Best, Marco -- Marco Gavanelli, Ph.D. in Computer Science Dept of Engineering University of Ferrara Tel/Fax +39-0532-97-4833 http://www.ing.unife.it/docenti/MarcoGavanelli/Received on Tue May 04 2010 - 08:40:38 CEST
This archive was generated by hypermail 2.3.0 : Tue Jun 04 2024 - 18:13:21 CEST