Space constraints problem

Started by plaldw, March 23, 2014, 11:12:22 AM

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plaldw

my school has two campus, a teacher may teaching in campus A in am (hour 1.2.3.4), and teaching in campus B in pm (hour 5.6.7.8), but can not change campus in am or pm.
FET has constraint "Min gaps between building changes for a teacher", but there's no gap in hour 4 and 5. which constraint is applicable  to this ? thanks!

Liviu Lalescu

To use official FET, I think you could double the number of days and consider each day to have 4 hours. The first FET day is Monday 1-4, the second FET day is Monday 5-8, the third FET day is Tuesday 1-4, and so on.

The only ugly thing might be the final aspect of the timetables, with a double number of days and half the length of the days.

Volker Dirr

Or an other workaround:

currently there are hours 1, 2, 3, 4, 5, 6, 7 and 8

now add add a new pseudo hours. 1, 2, 3, 4, p1, p2, p3, p4, 5, 6 ,7 , 8
and add constraint min gaps between building changes = 4.

plaldw

"add a new pseudo hours" is a good idea, but i think a new type of  constraint "building not change in a duration" is necessary.

Liviu Lalescu

I added this in the TODO:

Max building changes in a time interval.

But I won't make this soon, I think. Thank you for your suggestion!

Zsolt Udvari

If can know which activities are in campusA and campusB I think you should add a time constraint.

Eg. if activity1,2,3 and 4 are in campusA and 5,6,7,8 in campusB should add "An activity has a preferred starting time" and set to hour 1,2,3,4 and activity5,6,7,8 set to hour5,6,7.