How to capture the outline of a data point so that it looks like the outline of an island

Help
1

The results are as follows:
image

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I have tried convex hull but its effect is not what I want. What I want is a way to fit the outline of the small island around the data point like the picture I uploaded.

4

Have a look at

Or alternatively d3-contour:

5

Thank you very much for your answer, it has inspired me how to solve this problem

6

I also found this more relevant to my needs.

7

Nice! Note that this link is an unchanged fork of Fil’s notebook @fil/alpha-shapes:

8

Excellent thread! Thank you all!