algorithm like convex hull, but that return the lower area polygon containing all points

Question

I have a spatial software, In a database I have for each street in several cities, the lat/long of each street. And every street belongs to a zone. I'm trying to get polygons for each zone, and to do this, I need an algorithm that give me as result the smallest polygon that covers a number of points. Very similar to convex hull. convex hull is useless because it resolved it like this:

enter image description here

And, what I need is this:

enter image description here

score 2 · Answer 1 · answered Nov 08 '13 at 19:24

2

I think I have the answer, Concave hull algorithm.

answered Nov 08 '13 at 19:24

Ariel Larraburu

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has any implementation? – sendreams Aug 03 '14 at 10:26

score 0 · Answer 2 · answered Jan 28 '15 at 09:26

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There is a working npm module for calculating concave hull here: https://www.npmjs.com/package/hull.js

I use it. It's written in javascript and you can use it on server with Node.js.

answered Jan 28 '15 at 09:26

karakulj

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algorithm like convex hull, but that return the lower area polygon containing all points

2 Answers2