Tag+Space constraints

[catalin]

Hi,
I've checked the data again and it seems that I needed more Course rooms.... When I added them FET could solve the timetable even with 100% all contraints

One more question: is it possible to have for students one free day? For teachers I use "max days per week for all/one teacher/s"
Thanks
Catalin

[Liviu Lalescu]

Hi,
I've checked the data again and it seems that I needed more Course rooms.... When I added them FET could solve the timetable even with 100% all contraints

That is good to hear!

One more question: is it possible to have for students one free day? For teachers I use "max days per week for all/one teacher/s"
Thanks
Catalin

There is no direct constraint. There is possible this trick: use constraint students interval max days per week, interval = whole day, max days=n_days_per_week-1. Let me know if it works.

[catalin]

It does not... it allocates about 480/560 activities this way...
questions:
-why does this constraint (students work in an hourly interval max days per week) has to weight 100%?
-why max days per week for all/one teacher/s has to be 100%?

if the weight could be lowered it would be more flexible, isn't it?

Thanks,
Catalin

[Liviu Lalescu]

It does not... it allocates about 480/560 activities this way...

Maybe you could try to see which students set has problems and remove this constraint from it (FET will tell you the impossible activity, and the students are of this activity).

questions:
-why does this constraint (students work in an hourly interval max days per week) has to weight 100%?
-why max days per week for all/one teacher/s has to be 100%?

if the weight could be lowered it would be more flexible, isn't it?

Thanks,
Catalin

Hmm...sensitive part.

I could not make it. I would like. But the fact is that FET will not respect this constraint unless it has a very high weight, say >99.99. And normal users don't know this. Also, weight under 100% for these constraints will complicate things a lot.

I hope people learning my current algorithm will come up with a better one.

Now let me tell you something: a person told me this: aSc timetables (commercial program), he generated timetables, and aSc, which automatically tries to minimize teachers' gaps, found a solution with 4 gaps per week. When this person put maximum gaps 2 per week, aSc was again able to find a solution. What can we learn? That constraint max gaps per week for teachers with less than 100% weight will not find the optimal solution (aSc probably adds a constraint max gaps per week for teachers with weight <100% if you don't specifically tell it the maximum gaps per week, in which case it adds a constraint with 100% weight).

So, if you put weight under 100%, you'll get worse timetables than it is possible.

Let me know if I was clear.