[rules-users] newbie: Can rules planner provide me with the "single-steps" to the optimal binpacking solution ?

Geoffrey De Smet ge0ffrey.spam at gmail.com
Wed Nov 9 10:48:48 EST 2011


Drools Planner can solve this problem for you.
Here's a presentation that shows the code for a 3D bin packing problem:
   
http://www.slideshare.net/ge0ffrey/judcon-london-2011-bin-packing-with-drools-planner-by-example
To try it yourself, download the planner zip and run the example 
"CloudBalance".

Note that A* can't solve bin packing in scalable manner, because bin 
packing is np complete.
> Each change (movement of items between bins) has a certain cost, and I 
> would like to have a list of the least-cost path.
The roaddef2012 machinereassignement example (new on master) has the 
same problem.
The trick is that each Assignment holds the time, changeCost, the 
originalBin and the newBin. The newBin is the planning variable.
Then just add score rules that add the changeCost to the score when 
originalBin != newBin.

Op 09-11-11 15:45, Itai Frenkel schreef:
>
> Hello,
>
> I would like to solve a 2D binpacking problem. I have an existing 
> bin-packing solution and would like to make it more "optimized". Each 
> change (movement of items between bins) has a certain cost, and I 
> would like to have a list of the least-cost path. There is more than 
> one solution that is optimal.
>
> Given an existing bin-packing solution I can tell if it is the optimal 
> solution, and if not I can have a gross estimate to the distance to 
> the optimal solution (although it is not guaranteed to be less than 
> the actual distance).
>
> It sounds to me that I need something like the A-Star algorithm. Can 
> Drools help me in solving this problem ?
>
> Thanks,
>
> Itai
>
>
> _______________________________________________
> rules-users mailing list
> rules-users at lists.jboss.org
> https://lists.jboss.org/mailman/listinfo/rules-users

-- 
With kind regards,
Geoffrey De Smet

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