skmeans seems to only do 2 clusters #181

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1. g-roma commented on Jun 27, 2022

   

   g-roma

   on Jun 27, 2022

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   I can't check the Max help file, does it also happen in SC? Swapping SKMeans in the KMeans help file code works as expected for me: 4 clusters, but based on angle. In some runs you may end up with an empty cluster.
2. tremblap commented on Jun 29, 2022

   

   tremblap

   on Jun 29, 2022

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   It does happen in SC too:

   b = FluidDataSet(s)
   b.read(FluidFilesPath() ++ "../Data/circles.json")
   b.print
   
   c = FluidSKMeans(s,numClusters: 4)
   
   d = FluidLabelSet(s)
   
   // run this many times. always 2 classes full 2 empty
   c.clear
   c.fitPredict(b,d,{|x|x.postln})
   
   d.dump{|i|e=i}
   b.dump{|i|f=i}
   // e.postln
   // f.postln
   
   // graphic evidence
   ~fp = FluidPlotter(bounds:Rect(200,200,600,600),dict:f).categories_(e);
   
3. g-roma commented on Jun 30, 2022

   

   g-roma

   on Jun 30, 2022

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   The data in circles.json does not really have 4 clusters in the angular direction, so I would not expect the algorithm to find them. The code below generates a set of points clustered by angle. The algorithm may still fail due to random initialization (especially with smaller datasets), but most of the time it finds them (substitute in the FluidKMeans help file).

   ~points = (4.collect{|i|
   128.collect{
   var angle = 0.1.rand + (i * pi / 2);
   var r = 1.0.rand;
   [r* angle.cos, r * angle.sin]
   }}).flatten(1);
4. tremblap commented on Oct 19, 2024

   

   tremblap

   on Oct 19, 2024

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   ok it happens that the data needs to be centred on 0 to behave quickly on our code. I'll add a note to the helpfile and add an example that makes it clear.
5. tremblap commented on Dec 10, 2025

   

   tremblap

   on Dec 10, 2025

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   fixed by #286