Originally posted by: Capablanca93

IloActivity act;
IloModel model;
// act = ...
// model = ...
IloIntVar startDate(env);
IloConstraint ct1 = act.startsAt(startDate);
IloConstraint ct = ((startDate % (60*5)) == 0); // 5 minutes
model.add(ct && ct1);

with only ct1, model extracts, with ct && ct1, the model can't extract (because of ct according to the exception message).
Where am I wrong ?

Sincerly.
#CPOptimizer
#DecisionOptimization

Originally posted by: SystemAdmin

Hello,
In fact, the modulo expression (%) is not supported in Solver. If you want to remove some possible values from the domain of the start time of an activity, you have two options:

(1) either directly define a start variable with the discrete set of possible values:

// Option (1) IloIntArray possStarts(env); 

for (IloInt i=0; i<horizon; i+=300) 
{ possStarts.add(i); 
} IloIntVar startDate(env, possStarts); model.add(act.startsAt(startDate));

(2) or, in Scheduler by defining a calendar on a resource with shift objects:

// Option (2) IloDiscreteResource res(env, 10000); 
// Large capacity IloIntervalList noStart(env, 0, horizon); 

for (IloInt i=0; i<horizon; i+=300) 
{ noStart.addInterval(i+1, i+300); 
// Activities cannot start on [i+1,i+300) 
} IloShiftListObject shifts(env, noStart, IloShiftListObject::OnStart); IloCalendar cal(env); cal.addShiftObject(shifts); res.setCalendar(cal); model.add(act.requires(res));

The advantage of the second option is that the calendar will be applied to all activities requiring the resource.
In a more general context, you could also replace (x%a) by (x - a*IloDiv(x,a)).

Hope it helps.
#CPOptimizer
#DecisionOptimization