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Messages - Volker Dirr

#2881
Get Help / Re: University Timetable
December 21, 2009, 10:23:26 PM
pss: hmmm... maybe a better solution (better, because it fit better into fet style and maybe is also easier to code) is this:
the current constraint "preferred rooms" need a radio buttion, so you can select different options:
1. radio button: "take one of the selected rooms" (this is the current style)
2. radio button: "take all of the seleted rooms" (that is what maybe help you, but it mean it will select exactly your selected rooms. that style is good to "gesamtschulen", i am not sure about your situation.)

Maybe insted of radio button just an integer selection of "you X of the seleted rooms" (so current style is "1" and the X can be increased up to number of selected rooms)
#2882
Get Help / Re: University Timetable
December 21, 2009, 08:47:13 PM
Quote[...]
One problem I came accross is the following:
Here is an example of a course:

Choose 3 subjects from 18 subjects.
Choose one subject from 3 subjects
Choose one subject from 2 subjects
Compulaory subjects are 10

One method of solving this is to make use of many dummy activities [...]

Is there any one that do have a solution for my problem? it will be highly appreciated.

The only simplify i can think of are the "choose "1" subject" courses if you can do a conflict free activity planning. (so i mean each of that subject is teached by an other teacher.).

you have two times "choose 1 subject", just call it with a good name (you now better then me):
Choose one subject from 3 subjects: maybe call it "compulsory elective 1"
Choose one subject from 2 subjects: maybe call it "compulsory elective 2"

so you just use one activity with subject "compulsory elective 1", but all teachers and the whole group into this activity.

the "problem" is: you still need to add a dummy activity with same starting time constraint if you need room constraints.

would it help you if you do it that way and you can choose something like "each teacher need his own room". (so this attribute is related to an activity?!)
i am not sure if it is (easy) to code. i am sure some schools (that school systems are called "Gesamtschule" in germany) also need such a feature.

let's wait for livius answer.

ps: i think an activity attribute like "number of needed rooms" would be better then my previous suggustion, but i am not sure how to care about the room capacity correct in that case. so there are more settings needed?
#2883
Get Help / Re: A difficult course
December 11, 2009, 06:49:49 PM
to understand the problem better allow all 14:30 periods to teacher GILMA DE LA PAZ.

generate my simplified samplefile and you will see it is solveable. think yourself why it is no solveable - why it is not solveable if you disallow the periods.

just allowing that to your whole samplefile is not enough. if you want to solve your whole samplefile you must remove some constraints.

did you check the statistics? maybe you add to many activities? if not: you need to allow more teacher periods.
#2884
Get Help / Re: A difficult course
December 11, 2009, 06:31:06 PM
i can't see the 3+3+3+3+2 activities.

also your samplefile is impossible in group SECRETARIADO I, because you disallowed to many teacher hours.

compare attached minimilizied file. it is not solveable, because you need to allow also some late periods to some teachers.
#2885
Get Help / Re: A difficult course
December 10, 2009, 06:45:40 PM
A 3+3+3+3+2 activity is possible. compare attachment.

you must have done an (other) misstake. (Maybe the teacher has only 4 allowed working days, ...).

If you publish your sampleset we maybe can check it.
#2886
Get Help / Re: Rooms not being calculated in timetable
November 05, 2009, 07:19:07 PM
please use "an activity has a prefered room". it refer only to a split (sub)activity. Not to the whole activity.
#2887
Get Help / Re: teachers assigned continuously
October 15, 2009, 08:30:23 PM
i am not 100% sure if i understood correct, but i think you can tag each activity ans use a max hours continously constraint for that tag.
#2888
Get Help / Re: teachers assigned continuously
October 13, 2009, 09:06:22 PM
please explain your problem with an example.
#2889
Quote
it would be great work if you make xml file with the initial order of placing activities at the Generating progress start so that we can read this file to know the activities order,
then you can only update text file with the max placed activities and the time of max placed activities.
then: we will find the last activity id at the xml file according to the max placed activities,so we can find the difficult Activity.

that doesn't work, because the order (can) change while generating.
#2890
writing it in a file will also need very much space on hard disc.

if you use linux you can also see a logging in the shell/command line.
#2891
QuoteThe only thing that gives me a lot of problems is this:
I have like 50 teachers. Aproximately 10 of them work part time and should do a min and a max of 3 days. the other 40 teachers work a min and a max of 5 days. if I use this constraint for all teachers, there's no way that the specific restriction of "min/max days for a teacher" works. The min days is exclusive. I should enter min days for a teacher 50 times. Is there a way that min days for all teachers is overwritten by more specific restriction of min days for a teacher?

There are 3 variants possible:

1. variant: like liviu (and you) desriped: add a constraint to every teacher.

2. variant: add a min n days constraint with 4 days to all teachers. also add a min n days constraint with 5 days to each single teacher that need 5 days. (so overall you add 1+40=41 constraints.)

3. variant: add a min n day constraint with 5 days to all teachers. also add an pseudo activity to each of the 10 teachers that also should have min 4 days. that activity must of course lock a whole day (so it might be a little bit more complicated if you also use a midday break or things like that.). so overall you need to add 1 constraint and 10 activitities.
If you don't like the displayed html table in this variant, you just need to load the solution as soon as you generated the final timetable. delete the pseudo activities and the min n day constraint and generate again (that just need a second, because all activities are locked).
#2892
Get Help / Re: Question about spreading subactivities...
September 29, 2009, 11:39:16 PM
QuoteI have a 5 hours activity splitted 2+1+1+1.

How can I constraint those subactivities to obtain that never the 2 hours component can be placed near a 1 hour subactivity?

what do you mean with "near"?

If you mean "not at the same day", then you can:

solution a:
add another min 1 day constraint with 100% so s1 and s2.
add another min 1 day constraint with 100% so s1 and s3.
add another min 1 day constraint with 100% so s1 and s4.

or
solution b:
give this activity an activity tag.
add constraint activity tag max 2 hours per day


if you mean "there must be a 'free' day bewteen", then:
solution c:
add another min 2 day constraint with 100% so s1 and s2.
add another min 2 day constraint with 100% so s1 and s3.
add another min 2 day constraint with 100% so s1 and s4.

if you have only a 5 days week, then it also mean s1 can be only monday or friday, so you can also use a constraint preferd time for s1 (that will improve speed).
#2893
Get Help / Re: combination of constraints
September 26, 2009, 12:20:19 PM
QuoteTwo periods incommpatible same day
so teacher/students can have lesson either periods 3-4 or 5-6 but not both

You can do that with the new constraint that is included in the current snapshot.
just add an activity tag "lunch" and say the activity tag is allowed only once per day.
but it doesn't always help, because it mean you need an activity "lunch". that will be difficult if you have teachers that teach only a few hours per week and also use a max gaps constraint.

similar if you just simply use a min n day constraint.

Quote
2-we can also deal with Silvia's case by a new constraint like this:
Max hours continuosely for a teacher in an interval
Silvia would set: Max=1 for period 5-7

by this you don't need a "lunch" activity. yes, that is maybe a nice solution. i am not 100% sure if it fit to all teachers, because i don't know about silvias teachers that work only half time.

#2894
Get Help / Re: How to print statistics !!?
September 02, 2009, 07:36:43 PM
the statistics can be sadly pretty hugh.
most webbrowsers have problems to print so hugh papers.

so my only hint is:
use landscape format.
if you want to print for example subjects-studendts-statistics please also check the students-subjects-statistic. it is the "same". select the table that is smaller (fronm left to right).
then reduce the fontsize until you can see in the print preview that it fit on the paper (from left to right). (fireofox has as "automatic" selection for that.) and print.

(so my hint is: if you can't print on a single sheet, then the width should fir on a single sheet. the hight can be printed on several sheets.)


what do you think, should i print in the statistics only the hours but not seperated by activity tags? that will save some space. i guess most guys don't need to know the activity tags and the seperated hours of the different activity tags in the statistics.
#2895
Get Help / Re: Display HTML
September 01, 2009, 04:37:05 PM
if you sent me your file also sent me the css file.
or better: sent the fet file.

if you want to print like last year, just go into fet->settings and disable "print activities with same starting time". (of course you need the generate (a solution) again.)