[rules-users] Planner with a list of planning variables

[Geoffrey De Smet]

On 15-01-14 21:36, jonathan.labin wrote:
> I have a related question and I'd like to ask it by extending the domain
> described here.
>
> Say that instead of the solution being one recipe, I am building a
> multiple-course meal of recipes.
> The problem will define the course slots including the maximum number of
> ingredients that can be used and the list of ingredients allowed for the
> slots of that course.
> Not all courses must have a recipe built.  If the constraints of the guests
> can be satisfied with fewer courses, the caterer saves money.
>
> Each course is one recipe as described here: a list of ingredients
> (in my case i don't particularly care about the order of the ingredients
> within the recipe).  Certainly each recipe does not need to use it's maximum
> number of ingredients.
>
> In my current implementation, I have a flattened list of assignment Planning
> Entities where each assignment represents an ingredient slot of a course
> mapped ingredient).
> For example if the first course has a maximum of 5 ingredients, the second
> course has a maximum of 10 ingredients, and the third has a maximum of 3
> ingredients, my problem would have a list containing 18 Planning Entities
> all in one list.
>
> The trouble with this approach is that each slot is a separate entity.  This
> means that assigning the ingredient to each of the 5 possible slots of first
> course is considered a separate solution when in reality it doesn't matter
> which slot of the course the ingredient ends up in.  This makes the search
> space much larger than it needs to be and results in a lot of swapping of
> ingredient assignments within the same course which results in no change in
> score.
The curriculum course example had the same problem:
Lectures (= entities) belonging to the same course are interchangeable.
Therefore, I configured the swapMoveSelector as such:
       <swapMoveSelector>
<filterClass>org.optaplanner.examples.curriculumcourse.solver.move.DifferentCourseSwapMoveFilter</filterClass>
       </swapMoveSelector>
>
> Is there a recommended pattern to model this domain efficiently?  Is there a
> modification that I can apply to my current representation of this domain
> which will allow an ingredient assigned to any slot of a course to be
> considered the same?
This cannot (currently) be expressed declaratively on the domain.
We might want to support that in the future (so the filterClass is 
automatically applied on the swapMoveSelector etc),
feel free to create a jira.
>
> Thanks,
>
> Jon
>
>
>
> --
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