Number of students?

[Zsolt Udvari]

Hi all!

I get the next error:

Cannot generate timetable, because for activity with id==269 you have no allowed preferred room (from the allowed number of students and preferred room(s) constraints)

Does it mean that the specified activity has more student than the preferred rooms capacity? Or maybe is it a bug?
Because I've checked: its subject is Chem which room has 36 capacity. I must down manually the number of students to 30 to FET's accept. And it doesn't exist 100% weight... What's wrong?

[Liviu Lalescu]

I just checked the code. Indeed, it doesn't matter the weight. I might have judged at that time that the constraint is wrong and must be changed. Otherwise FET will lose time trying to fulfill it.

About the number of students, I think you have an error. Please check: the number of students for activity is -1 (computed automatically), there is only one students set, with the correct number of students, and the preferred rooms' capacities.

Best would be to send me your file.

[Zsolt Udvari]

About the number of students, I think you have an error. Please check: the number of students for activity is -1 (computed automatically), there is only one students set, with the correct number of students, and the preferred rooms' capacities.

I think I've checked all you said:
- number of students is -1
- there is only one students set
- capacity is ok

Here is the input-file.

[Liviu Lalescu]

Activity 267 has 36 students and, among others, preferred room 84% to room F3. Room F3 has capacity 30.

[Zsolt Udvari]

Activity 267 has 36 students and, among others, preferred room 84% to room F3. Room F3 has capacity 30.

Hm, you've right. Your eye is like eagle's eye Thanks!

Activity 267 has many preferred room with various weights (room of subject, room of class, any other) - sometimes can lower capacity than the number of students. If weight is lower than 100% should check the capacities?

[Liviu Lalescu]

Quote from my reply #1:

I just checked the code. Indeed, it doesn't matter the weight. I might have judged at that time that the constraint is wrong and must be changed. Otherwise FET will lose time trying to fulfill it.

Or a better argument, FET should indicate the user that the constraint is impossible.