I have a set of points on a circumference:
points = Map[Normalize, RandomReal[{-1, 1}, {3000, 2}]]
And I want to plot them and color the plot according to the density of points. You see, ListPlot[points]
will just give me that, a simple plot, on which I can't see the distribution of the points on the circle.
Maybe there is an option?
I hope you guys can understand what I'm asking.
Edit/Follow-up
I used SmoothDensityHistogram[points, ColorFunction -> "Rainbow"]
Now, it's not really what I'm looking for. I kind of wanted it to look like the original plot, just the circumference.
Answer
Here is what I think you wanted:
points = Map[Normalize, RandomReal[{-1, 1}, {3000, 2}]];
d = SmoothKernelDistribution[points];
colors = Hue /@ Rescale[PDF[d, #] & /@ points];
Graphics[Transpose[{colors, Point /@ points}]]
Here the SmoothKernelDistribution
is evaluated in the plane, giving you a two-dimensional interpretation of density. One could also understand your question as asking for a one-dimensional density of points only on the circle. But I followed the simplest interpretation here.
For completeness, here is an implementation using ListPlot
. The colors are contained in PlotStyle
, but in order to make them apply to each point individually I have to add another level of depth to the list points
:
ListPlot[Map[List, points], PlotStyle -> colors,
AspectRatio -> Automatic]
I may as well add the treatment of the density as purely one-dimensional on the circle: here I convert the elements of points
to their polar angle coordinate, and then calculate the density in this polar angle:
arc = ArcTan /@ points;
d = SmoothKernelDistribution[arc];
colors = Hue /@ Rescale[PDF[d, #] & /@ arc];
Then proceed with the plots as above. One can of course play more with the options of SmoothKernelDistribution
, depending on your application.
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