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Questions tagged [convex-hull]

Convex-hull of a set of points X in a Euclidean space is the convex set with smallest area that contains all points of X.

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largest prefix of array of vertices that forms a convex polygon

Related to: Polygon Decomposition - Removing Concave Points to Form Convex Polygons I am looking for an algorithm to do the following: The input is an array of 2D points (P0…PN-1). The length N of the array varies (3 ≤ N < ∞) For any M ≤ N there…
finnw
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Maximum distance between points in a convex hull

I am solving a problem in which I need to find the maximum distance between two points on a plane (2D) .So there is an O(n^2) approach in which I calculate distance between every point in the graph . I also implemented a convex hull algorithm now my…
sid597
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Find two most distant points in a set of points in 3D space

I need to find the diameter of the points cloud (two points with maximum distance between them) in 3-dimensional space. As a temporary solution, right now I'm just iterating through all possible pairs and comparing the distance between them, which…
Chan Kha Vu
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Android Google Maps PolygonOptions not plotted from given set of coordinates

I am trying to plot a complex polygon around a route, following its steps with a given radius. To do so I drew 50-sided uniform polygons (which are practically circles) around each step (coordinate) of the route. Now I obtain a set of coordinates of…
AymanKun
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Algorithm to order a set of points clockwise and make sure the path connecting the points is closed

I have been going about this problem in many different ways, and after a month of trying to do it on my own I think it is time for fresh eyes to take a look at it. I am trying to make an image scaling application for re-sizing 8-bit sprites and…
Jedi_Maseter_Sam
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Is there a linear-time algorithm for finding the convex hull of a complex polygon?

I know there's a worst-case O(n log n) algorithm for finding the convex hull of a complex polygon and a worst-case O(n) algorithm for finding the convex hull of a simple polygon. Is there a worst-case O(n) algorithm for finding the convex hull of a…
Daniel Stutzbach
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How can I make convex hulls of multiple group network nodes in D3.js

I am trying to make network diagram in which the nodes are grouped by a property, and in which they are bundled by group with both location (force layout) and using a convex hull. Like this but without the click to collapse/expand. That model/code…
Aaron Bramson
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Polygon/contour around subset of vertices on graph (more precise than mark.groups in igraph)

Problem definition I need to produce a number of specific graphs, and on these graphs, highlight subsets of vertices (nodes) by drawing a contour/polygon/range around or over them (see image below). A graph may have multiple of these…
user3554004
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How can I count the number of tips in an image in OpenCV?

I have a set of hiragana characters and I would like to count the number of end points/ tips the character have. example: input image: desired output image: I have tried using convex hull code: (based on opencv tutorial here) …
R.A.
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Converting convex hull to binary mask

I want to generate a binary mask that has ones for all voxels inside and zeros for all voxels outside a volume. The volume is defined by the convex hull around a set of 3D coordinates (<100; some of the coordinates are inside the volume). I can get…
Jonas
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Algorithm intersecting polytope and half line

I am looking for an algorithm in R to intersect a convex polytope with a line segment. I found several post here on stack exchange for in the plane but I am wondering if this algorithms exists in higher dimensions. My google searches didn't really…
MrOperator
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How can I find if a point lies inside or outside of ConvexHull?

I have array of points in numpy and I compute their ConvexHull by (scipy.spatial.ConvexHull not scipy.spatial.Delaunay.convex_hull), now I wanna know if I add new point to my array is this point lies inside the convexhull of the point cloud or not?…
Am1rr3zA
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Smooth Convex Hull

I have started working a convex hull algorithm and was wondering what method I could employ to smooth the polygon edge. The outline of the hull is not smooth. What I would like to do is make the lines through the vertices smoother, so that they are…
beliskna
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Convex hulls with ggbiplot

Based on the help below I tried this script for plotting PCA with Convex hulls without success, any idea how can I solve it? library(ggbiplot) library(plyr) data <-read.csv("C:/Users/AAA.csv") my.pca <- prcomp(data[,1:9] , scale. =…
wrek
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Finding the upper (convex) hull in higher dimension (3+)

Sorry for my broken English. I want to find the lower envelope of a plenty of linear equations. This is mapped to the problem of finding the upper (convex) hull in its dual plane. As I surveyed, there are a couple methods to find an upper hull, but…
Phychus
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