I am doing clustering and have a plot as below:-

GaussianRandomData[n_Integer,p_,sigma_]:=Table[p+{Re[#],Im[#],RandomReal[NormalDistribution[0,sigma]]}&[RandomReal[NormalDistribution[0,sigma]] E^(I RandomReal[{0,2 π}])],{n}];

The plot of virus outbreak

Is it possible to wrap the points up by some surfaces (either transparent or not; either just coloring at the boundaries or filled up; either elliptic or irregular)? That would be similar to the following 2D case:-

enter image description here

If being wrapped by surfaces is not possible, is it possible to just add lines linking the points of the same cluster?

Many thanks!

  • $\begingroup$ Look at ConvexHullMesh $\endgroup$ – OkkesDulgerci Jun 13 '18 at 13:58
 Show[ListPointPlot3D[data1, PlotTheme -> "Business", 
  PlotStyle -> {AbsolutePointSize[3]}], 
    Style[2, ColorData[97, i], Opacity[0.2]]]}, {i, 3}]]

enter image description here

| improve this answer | |
  • $\begingroup$ Thanks for reply. Is there a way to change the surfaces into 3 different colors? I think the change should be at Style[2, Opacity[0.5]]? $\endgroup$ – H42 Jun 13 '18 at 14:30
  • $\begingroup$ Style[2, Orange, Opacity[0.5]] $\endgroup$ – OkkesDulgerci Jun 13 '18 at 14:37
  • $\begingroup$ Is this what you are looking for or what you want is smallest ball or ellipsoid that contain all points? $\endgroup$ – OkkesDulgerci Jun 13 '18 at 14:39
  • $\begingroup$ I just want a clear illustration to show separated clusters. In my real data, there are several thousand points and there are around 20 to 100 clusters overlapping each other. It is likely that I will keep refreshing the plot with different parameters to analyze the data, so I hope the selected method would be more computationally efficient (or not too worse) than the other methods. $\endgroup$ – H42 Jun 13 '18 at 14:52
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    $\begingroup$ For my real case in which the clusters overlapping each other, I noted that ConvexHullMesh is a better solution than BoundingRegion[#,"FastEllipsoid"]&, since the ellipsoid would be much larger than the hull, making the graph less illustrative since the large ellipsoids overlap each other too much. $\endgroup$ – H42 Jun 13 '18 at 15:42

Yu could use BoundingRegion with the "FastEllipsoid" as second argument:

    ColorData[97] /@ Range[3],
    Point /@ data1
    ColorData[97] /@ Range[3], 
    BoundingRegion[#, "FastEllipsoid"] & /@ data1
 Lighting -> "Neutral"

enter image description here

See also the documenttion of BoundingRegion for further bounding shapes.

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