Oh, I see. That means that there is most likely a bug (could also be ok) in your own propagator.
Normally, a propagator must be monotonic: it never propagates more when it is run on bigger variables domains. Or with other words: the smaller the domains the more it propagates. Some propagation algorithms do not follow this which might lead to indeterminstic behavior as you observed. Check 22.9 in MPG. But most likely it is a bug in your propagator. Or do you use parallel search with several threads? This can also lead to non-deterministic behavior. Cheers Christian -- Christian Schulte, www.ict.kth.se/~cschulte/ > -----Original Message----- > From: Pascal Francq (Mailing lists) [mailto:mailing-l...@francq.info] > Sent: Thursday, May 23, 2013 5:43 PM > To: cschu...@kth.se > Subject: Re: [gecode-users] Consecutive instances of Gecode produce different > results > > I use two Gecode::IntVarArray variables I and v. The code for the constraints and > the branching is the following one : > > // Maximal value <= 1 > rel(*this,1>=sum(v)); > > // Sum_(i)(2*v[i]-Sum_(j,j<>i)(I[i,j])>=0 > for(size_t i=0;i<4;i++) > { > IntVar tmp[3]; > size_t idx(0); > for(size_t j=0;j<4;j++) > { > if(i==j) > continue; > if(idx) > tmp[idx]=expr(*this,tmp[idx-1]-abs(I[i,j])); > else > tmp[idx]=expr(*this,-abs(I[i,j])); > idx++; > } > rel(*this, 0<=2*v[i]+tmp[idx-1]); > } > > // Call my own propagator > choquetPropagator(*this,Test,v,I,Cost); > > // Make the branch > branch(*this,v,INT_VAR_SIZE_MIN(),INT_VAL_MIN()); > branch(*this,I,INT_VAR_SIZE_MIN(),INT_VAL_MIN()); > > > Le 23/05/13 17:23, Christian Schulte a écrit : > > Could you tell us which constraints and which branchings you are using? > > > > Best > > Christian > > > > -- > > Christian Schulte, Professor of Computer Science, KTH, > > www.ict.kth.se/~cschulte/ > > > > > > -----Original Message----- > > From: users-boun...@gecode.org [mailto:users-boun...@gecode.org] On > > Behalf Of Pascal Francq (Mailing lists) > > Sent: Thursday, May 23, 2013 4:59 PM > > To: users@gecode.org > > Subject: [gecode-users] Consecutive instances of Gecode produce > > different results > > > > Hi, > > I have a strange problem : I have a function that runs a Gecode > > instance for a particular problem. When I call the function several > > times, the result of the first run sometimes differs from those of the other > ones. > > I have make some runs with valgrind, but I see nothing. Has anyone an > > idea where to search ? > > -- > > Dr. Pascal Francq > > Belgium > > > > _______________________________________________ > > Gecode users mailing list > > users@gecode.org > > https://www.gecode.org/mailman/listinfo/gecode-users > > > > > -- > Dr. Pascal Francq > Belgium _______________________________________________ Gecode users mailing list users@gecode.org https://www.gecode.org/mailman/listinfo/gecode-users
