Originally posted by: SergeyPolyakovskiy

Dear All,

In my problem, I would like to have a flexible duration, yet a flexible contribution dependent on a set of variables for a job used in the cumulative function. For example, let interval variable a be of size 10 and consume 10 units of a resource when variable x in {0,1} takes the value of 1. Otherwise, when x=0, let a be of size 5 and consume 5 units.

Is there any smart way to implement this case without using any additional variables?

All the best,

Sergey

Originally posted by: rdumeur

Dear Sergei,

I think you could use two optional interval vars (One with size 10 and another with size 5).

Each interval var would be associated with a pulse (with height 10 and 5 respectively).

You can then use the 'alternative' constraint to represent such a choice, and then use presenceOf(resource_10) instead of having an additional variable x as in the following example:

dvar interval resource_5 optional size 5;
dvar interval resource_10 optional size 10;
dvar interval resource_choice;

cumulFunction c = pulse(resource_5, 5) + pulse(resource_10, 10);
dexpr int x = presenceOf(resource_10);

subject to {
        alternative(resource_choice, append(resource_5, resource_10));
}

execute {
        writeln("resource_5 " + resource_5);
        writeln("resource_10 " + resource_10);
        writeln("x " + x);
        writeln("c " + c);
}

Cheers,