Re: [tablix-list] Hard Timetables

From: Nicholas Robinson <>
Date: Thu Jun 09 2005 - 01:01:51 CEST


On Wednesday 08 June 2005 18:10, Tomaz Solc wrote:
> Hash: SHA1
> Hi
> > Paring down the problem, it seems that it is the high incidence of double
> > lessons combined with zero free lessons for classes and very few free
> > lessons for teachers. Of these, it always seems to be the doubles
> > (especially those that are 'same-time-as' another class or three) that
> > contribute the largest number of contributions to the fitness score.
> I think part of the problem is in your "" module. I've
> made a very simple ttf test case for it (consecutive-1.xml) and Tablix
> only finds a solution in 3 of 10 tries. The fitness function should
> probably be rewritten so that it would not try to enforce a specific
> order of tuples (see my earlier post).

I have made the change in test but although it has an effect in terms of speed
of convergence, in the relatively sparse reduced timetable such as I describe
here it doesn't affect the outcome. I'll send the diff through soon.

> I haven't yet looked at your "forcesametime.c" module though.

Intuitively, this should be less likely to have a problem as it is testing
equality rather than a difference.
> > So, if I can schedule the doubles as just described and then somehow
> > alter the configuration file for the remaining lessons to include the
> > doubles as fixed then I think I will be able to use tablix for real.
> This is probably the best way to do it right now.

I'll make a start in the next few days.

> I've made a few remarks in the Wiki about how this problem could be
> handled better in future versions (see bottom
> > 2. The 'fixed-period' handler would be implemented so that it removed all
> > other time, class, room and teacher resources in the resource domains for
> > the appropriate event tuple.
> This module is similar to fixed.c example in the Modules HOWTO.
I've checked my makedoc and I am getting errors, something about command dot
being missing -although I seem to be getting more useable documentation
within - I'll have a look for fixed.c

Best wishes

Received on Thu Jun 09 01:01:44 2005

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