Started by Liviu Lalescu, April 04, 2008, 05:46:46 PM
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QuoteOne more thing....I've notice that If you generated new time table.... some results had soft conflicts in it. Maybe after couple of times regenerate the time table.... FINALLY it shows 0 soft conflicts.... It means that FET can make no soft conflicts if u try many times... I'm just wondering, but why don't FET shows only the result for 0 soft conflicts. Maybe FET can optionally shows result that have some soft conflicts in it... Any suggestions??
QuoteThere is a little misunderstanding here: each time you generate, you start a new process, not depending on the previous process
QuoteYes... that part I understand. But wouldn't it better if FET can generate only 0 soft conflicts?? I have a suggestion. Maybe FET can be instructed to generate the time table UNTIL it can generate output of 0 soft conflicts in a certain amount of time like in the "generate multiple variants".... If it fail.... then we know that it is impossibly to achieve 0 soft conflicts.... Maybe after that FET can be instructed to find the remaining weight soft conflicts... For example below 3.0, below 1.5 etc.... Lower the weight figure, lower the soft conflicts in the time table right??? just a suggestion....u know the best... tq
QuoteThe best method is to generate, then strengthen one or more constraints, then try again, then again raise the weights to some constraints, until impossible to generate a new timetable, then go back one step.
QuoteI know another timetabling tool which has no weight for constraints
Quotebut I do not know how do they do it.
QuoteYes.... u can try to change this and that. But the way I see is like this, FET generate randomly according to the constraints right? For the first run , let say u got 3.0 soft conflicts and u made some adjusments. On the 2nd run, it changes everything because FET generate randomly...What I'm trying to say that becoz of FET generate randomly, sometimes the change we made before that doesn't change the output/outcome... Isn't it???
QuoteQuoteI know another timetabling tool which has no weight for constraintswhich one?? do you have their name and website?
QuoteQuotebut I do not know how do they do it.just ask them... hehe
QuoteI am sorry, but I do not understand. If you raise the weights, then probably the timetable will have less conflicts, but not always. But you can generate again.
QuoteI added that in the TODO, but I am not sure if a solution exists.Edit: it is impossible. FET cannot generate a solution with maximum say 2 (or 10) soft conflicts. The solution is generated gradually and it is impossible for the algorithm to do that. If it were a way, I would have done it a long time ago.
Quote(ii) longer run time to generate time table with increasing value for remaining soft conflicts (0.5, 1.0, 1.5 etc)
QuoteI think that is not a good idea.Reason:A user might increase the value for remaining soft conflicts and he might be unhappy about the results (if he ever get it. Think about a user that add low weights and low remaining soft conflicts, that guys will NEVER get a solution, because it will restart every few minutes without a result.)The problem is, that a user might not understand, that he can increase the weight to get a perfect timetable.So users that don't understand this mixed weight and value for remaining soft conflicts will get bad or even no timetable.Only the value for remaining soft conflicts (without weight) is bad, because a user can't affect single constraints anymore.