Well, yes. But one still needs to implement it... Maybe I'll announce a master thesis for some soft constraints because they are pretty useful and I got interested in them for some other reasons, too.
Christian -- Christian Schulte, www.it.kth.se/~cschulte/ -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Malcolm Ryan Sent: Monday, March 02, 2009 5:01 AM To: gecode list Subject: Re: [gecode-users] Reified Distinct Constraint Well a 'soft distinct' like this could easily be converted to a reified distinct: soft_distinct(args, nViolations); BoolVar b = post(space, ~(nViolations == 0)); Malcolm On 17/02/2009, at 8:36 PM, Christian Schulte wrote: > No, not really. I do not know what this distinct would be good for. > A more > useful one would be a soft distinct where the number of violations is > counted (there, one actually also could get some propagation). Check > for > example: > http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.3.7071 > > What do you need a reified distinct for? > > Christian > > -- > Christian Schulte, www.it.kth.se/~cschulte/ > > > -----Original Message----- > From: Max [mailto:[email protected]] > Sent: Tuesday, February 17, 2009 10:32 AM > To: Christian Schulte > Cc: 'gecode list' > Subject: Re: [gecode-users] Reified Distinct Constraint > > Thank you for the quick answer. > Is this feature planned for the release of GeCode3.0? > I just found a mail in the archive of somebody requesting the same > feature. > Currently i do use O(n^2) constraints for this, but i wanted to show > that i can transform it into a constant number of rules. > Thats why i would need the reified version. > > Max > > Christian Schulte wrote: >> No, there is no reified version. The best you can do at emulating >> is use >> excessive reification: Create O(n^2) reified disequality >> constraints for > all >> variable-variable pairs, and then the reified control variable is the >> conjunction of all the control variables from the disequalities. As >> said, >> not very good. >> >> Christian >> >> -- >> Christian Schulte, www.it.kth.se/~cschulte/ >> >> -----Original Message----- >> From: [email protected] [mailto:[email protected]] On >> Behalf >> Of Max Ostrowski >> Sent: Monday, February 16, 2009 2:21 PM >> To: gecode list >> Subject: [gecode-users] Reified Distinct Constraint >> >> I just found the distinct constraint, that hopefully makes all >> variables >> distinct. This could greatly reduce the number of constraints, as i >> am >> translating from a logic program. >> But i would need a reified version of the distinct constraint. >> I there any or can i at least emulate thie behaviour? >> >> Thank you in advance, >> Max >> > > > > _______________________________________________ > 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 _______________________________________________ Gecode users mailing list [email protected] https://www.gecode.org/mailman/listinfo/gecode-users
