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Questions tagged [concave-hull]

56 questions
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Geting sorted edge points from concave polygon

I have a set of points that form a concave polygon. I've performed a Delaunay triangulation on them that gives me this: Delaunay. I then used the descartes.PolygonPatch function to give me the concave polygon I want: Polygon. Now I want to recover…
phalanx
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OpenCV how to find contour (Concave hull) for list of points - Java

I'm new to openCV and find it really difficult to do some even basic stuff so I'll really appreciate Your help. My problem looks like that: I have a list of points consisting of geo coordinates (latitude, longitude) in format as (49.074454444,…
mkapiczy
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Number of spatial lines

Is there a way to find out the number of continuous spatial lines in a SpatialLinesDataFrame ? EG this would be 2 (the outer one and the inner one) : And this would be 1 : (Also, is there a way to get the total length of each of them ?)
François M.
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Filling in a concave polygon represented as a binary matrix

In my task, I represent a concave polygon as a matrix of ones and zeros, where one means that the given point belongs to the polygon. For instance, the following are a simple square and a u-shaped polygon: 0 0 0 0 0 0 0 0 0 0 0 0 1 1 0 0 1 1…
John Manak
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How to set up an array of objects to be in format { x: {Number}, y: {Number} }? Javascript

I'm trying to use: https://www.npmjs.com/package/concavehull And I don't know how to assign an array in order to use it with ConcaveHull npm. The documentation says "all you have to do is pass an array of objects that conform to the { x: {Number},…
karakulj
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Hull.js npm module Node.js returns convex hull instead of concave hull

I use this node.js module: https://www.npmjs.com/package/hull.js to calculate concave hull. On this link in the section "How it works" there are 3 steps about how it works. But in my case the algorithm stops on the 2nd step. So, it gives me convex…
karakulj
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find 3D concave Hull, surfaces given

I have a list of Surfaces defining a 3D Object. Those surfaces have the following constraints: each surface is defined with an array of vertices defining its border no holes are inside of an surface surfaces do not overlap or go through other…
Shiga
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How to create arcs on boundary points of voronoi?

I am writing some 2D graphic software. And in my project i used Voronoi algorithm. And result is correct as I expected (Pic 1). Then i want to add some feature on boundary points just like (Pic 2). So i think i need to implement Concave hull on…
Edmon
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Concave Hull From GPS Coordinates in Javascript

this is my first question in stackoverflow after reading a lot about concave hulls and alpha shapes but unfortunately I still have not found a working solution :( My input is a big array of GPS-Coordinates (lat,lon) (around 1000-2000 points)…
Patrick Stahel
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find polygon from bool-grid

I have a 2-dimensional array of bool like this The shape won't have any holes -- even if it has -- I'll ignore them. Now I want to find the Polygon embracing my shape: Is there any algorithm ready to use for this case? I couldn't find any, but I'm…
user2033412
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Points reconstruction

I would like to ask about one idea that I had and I haven't figured out the solution, my idea is about: Having a set of GPS coordinates point, which are covered by a rectangle, how to connect those points according to its shape, as I tried Quick…
bluewonder
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