Sorry it's RIchard again, you meant :
2014-06-12 11:50 GMT+02:00 Mikael Zayenz Lagerkvist <zay...@gmail.com>: > Richard Portelli skrev 12/06/14 10:32: > > Hello Christian, >> I would like to know if there is an easy way to implement a special >> constraint. >> I have an array with 10 numbers. >> My constraint would be : if you plot the array values in function of the >> index, you should have a wave aspect /\. >> For example with 10 numbers >> >> 1 3 5 9 11 7 6 5 4 2 0 (increasing then decreasing) There is no >> importance at witch index there is the inflexion point. >> >> Would you have an idea how to implement that in a clean way? >> >> > For reference, this is similar to the inflexion constraint ( > http://www.emn.fr/z-info/sdemasse/gccat/Cinflexion.html) with the number > of inflexions set to 1 (assuming that valleys are also ok). > > The simplest way in my opinion to model this constraint would be the > following. > > Assume the sequence of numbers is called x and has n entries. > Define a new boolean array of variables y with n-1 values. > For each place i in y, add the constraint > y[i] = (x[i] < y[i]) > (that is, reified ordering). > On the y variables, add the constraint regular(y, 1*0*) > > The ordering constraint and the regular expression can be modified to suit > your particular needs. > > Cheers, > Mikael > > _______________________________________________ > Gecode users mailing list > users@gecode.org > https://www.gecode.org/mailman/listinfo/gecode-users >
_______________________________________________ Gecode users mailing list users@gecode.org https://www.gecode.org/mailman/listinfo/gecode-users
