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Drools Planner can solve this problem for you.<br>
Here's a presentation that shows the code for a 3D bin packing
problem:<br>
<a class="moz-txt-link-freetext" href="http://www.slideshare.net/ge0ffrey/judcon-london-2011-bin-packing-with-drools-planner-by-example">http://www.slideshare.net/ge0ffrey/judcon-london-2011-bin-packing-with-drools-planner-by-example</a><br>
To try it yourself, download the planner zip and run the example
"CloudBalance".<br>
<br>
Note that A* can't solve bin packing in scalable manner, because bin
packing is np complete.<br>
<blockquote type="cite">Each change (movement of items between bins)
has a certain cost, and I would like to have a list of the
least-cost path.</blockquote>
The roaddef2012 machinereassignement example (new on master) has the
same problem.<br>
The trick is that each Assignment holds the time, changeCost, the
originalBin and the newBin. The newBin is the planning variable.<br>
Then just add score rules that add the changeCost to the score when
originalBin != newBin.<br>
<br>
Op 09-11-11 15:45, Itai Frenkel schreef:
<blockquote
cite="mid:937E2FF007587B4E85B50FAAE85799F530739AD298@IE2RD2XVS141.red002.local"
type="cite">
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<p class="MsoNormal" style="text-align: left; direction: ltr;
unicode-bidi: embed;">Hello,<o:p></o:p></p>
<p class="MsoNormal" style="text-align: left; direction: ltr;
unicode-bidi: embed;"><o:p> </o:p></p>
<p class="MsoNormal" style="text-align: left; direction: ltr;
unicode-bidi: embed;">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.<o:p></o:p></p>
<p class="MsoNormal" style="text-align: left; direction: ltr;
unicode-bidi: embed;"><o:p> </o:p></p>
<p class="MsoNormal" style="text-align: left; direction: ltr;
unicode-bidi: embed;">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). <o:p></o:p></p>
<p class="MsoNormal" style="text-align: left; direction: ltr;
unicode-bidi: embed;"><o:p> </o:p></p>
<p class="MsoNormal" style="text-align: left; direction: ltr;
unicode-bidi: embed;">It sounds to me that I need something
like the A-Star algorithm. Can Drools help me in solving this
problem ?<o:p></o:p></p>
<p class="MsoNormal" style="text-align: left; direction: ltr;
unicode-bidi: embed;"><o:p> </o:p></p>
<p class="MsoNormal" style="text-align: left; direction: ltr;
unicode-bidi: embed;">Thanks,<o:p></o:p></p>
<p class="MsoNormal" style="text-align: left; direction: ltr;
unicode-bidi: embed;">Itai<o:p></o:p></p>
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<pre class="moz-signature" cols="72">--
With kind regards,
Geoffrey De Smet</pre>
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