Minimum distance between afternoon

[Andrea Giordano]

My student have 2 afternoons per week.
I've been requested to locate this 2 afternoons non in consequent days but with almost 1 day distance (say for ex: on monday and wednesday, or thusday- friday) something like this... how can I do this since the constraint student  "max interval n days per week" is not provided.

[Liviu Lalescu]

Maybe there are some other tricks, but I see only one:

Don't you have two activities which you know for sure they are in the afternoon in different days? So add min days between them to 1? Or fix some 2 activities like that? (with constraint activities preferred time slots in the afternoon).

[Liviu Lalescu]

I think you can use the new constraint, activities occupy max time slots from selection. Activities = all activities of a students set. Time slots = Monday first slot of afternoon and Tuesday first slot of afternoon, Max occupied = 1. You need to add n_days_per_week-1 constraints for each students set.

The new constraint is available in the new snapshot, see Snapshots section here on forum. If it is not available anymore, it means the new FET-5.15.0 is ready for official download.

Please let me know.

[Frans]

Dear Liviu

Forgive me if I am a little slow. I refer to your previous posting.

My question is why is maximum occupied equal to 1? If classes must be on Tuesday late and Thursday late it means it is a maximum  of 2 and not 1.

Probably I do not understand the new constraint 100%, but I will get there.

Kind regards.

(I already read the help on the new constraint but is still not up to date.)

Frans

[Liviu Lalescu]

I meant reject working both on Monday and Tuesday afternoon, reject working both on Tuesday and Wednesday afternoon, Wed&Thu, Thu&Fri, Fri&Sat -> n_days_per_week-1 constraints.