Yes, sure it's useful, thank you. I'm just wondering whether a modification of the unary might be more efficient or not. In such a case, I could modify the source files of Gecode, by adding another (modified) unary constraint, otherwise... should I write an user-defined propagator?
I've the same doubt regarding the nooverlap, I'd like to achieve a generalization of it. In this generalization rectangles of the same "group" can overlap eachother, but they cannot overlap other rectangles of other groups. So the new nooverlap will take in input an IntArgs array which contains the group IDs. In your guide I read: "The constraints [nooverlap] are implemented by a naive propagator (considering pairwise no- overlap between rectangles including constructive disjunction, see also GCCAT: diffn), this will change in the future. " I could add a condition within the implementation of the nooverlap, that checks if the two rectangles belong to two different groups. Is it right? Do you have any suggestion? Thank you, Andrea On Wed, Oct 30, 2013 at 1:05 PM, Christian Schulte <cschu...@kth.se> wrote: > Hi,**** > > ** ** > > There is a generic trick for situations like this: you introduce new > variables tend', tstart' and tdur' and only enforce that they are equal to > tend, tstart, tdur respectively when the Boolean variable is 1. That means > if the Boolean variable is 0, the new variables can have whatever value.** > ** > > ** ** > > Hope that helps**** > > Christian**** > > ** ** > > --**** > > Christian Schulte, Professor of Computer Science, KTH, > www.ict.kth.se/~cschulte/**** > > ** ** > > *From:* users-boun...@gecode.org [mailto:users-boun...@gecode.org] *On > Behalf Of *Andrea Peano > *Sent:* Tuesday, October 29, 2013 10:21 AM > *To:* users@gecode.org > *Subject:* [gecode-users] Unary: Allow for negative durations when task > is not mandatory**** > > ** ** > > Hello all,**** > > I would modify the unary constraint in order to allow negative durations > (tend<tstart) when the boolvar m (mandatory) is 0.**** > > ** ** > > Is there an easy way to do this?**** > > ** ** > > Thank you,**** > > Andrea**** > -- Andrea Peano - PhD student Department of Engineering - University of Ferrara Tel: +39 0532 97 4827
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