Questions tagged [computational-geometry]

The study of computer algorithms which admit geometric descriptions, and geometric problems arising in association with such algorithms. The two major classes of problems are (a) efficient design of algorithms and data classes using geometric concepts and (b) representation and modelling of curves and surfaces.

1221 questions
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How to fit largest circle within Voronoi cells?

I have a list of Voronoi cells and would like to place the largest circle possible within each cell. What is the best way to do that? Many thanks, Arthur
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How can I approximate a complicated polygon, such that the curvature never exceeds some set limit?

This question is inspired by CNC toolpath generation, although I've become interested in it from a more theoretical perspective as well; the practical answer may be to find a CAD software tool that does exactly what I'm asking, but I am more curious…
monguin
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What is the best approach to find the nearest line segment (x1,y1), (x2,y2) from a point (x,y)?

Let's suppose the are three line segments in a plane, each line segment has coordinates (x1, y1) and (x2, y2). What is the best approach to find out the nearest line segment from a point (x, y)? Hint: use vectors dot product.
Ahmad Shakir
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Data structure to check if there are any points under query line segment

Let P be a set of points, where no three points are colinear and no two points have the same x- or y-coordinates. What is a good way of preprocessing P so that one can easily do queries in the below form: Given a line segment q, are there any points…
Joe 2.0
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Geometry: formula for 2D perspective transformation

Is there a way of describing an perspective transformation for one point in the 2dimenstion world? I know you can write translation for one point for instance as: $(x*a,y*b) = (x',y')$ where $a$ describes the translation in the $X$ dimension and $b$…
flor1an
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Precision in Programming Möbius transformations of the Riemann Sphere

Apologies if this is better asked on StackOverflow, but I thought the community here would be more likely to have an answer, even though it's related to coding. I'm coding up a little library for experimenting with the inversive geometry of the…
John
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What is a pseudodisk?

I'm reading a paper on computational geometry and the term pseudodisk popped up. A simple googling doesn't provide me with any mathematical definitions. Could anyone please explain to me the definition of a pseudodisk? Edit: For more context: "It…
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How to find the smallest enclosing quadrilateral for an irregular polygon

The context here is geo-location/geo-fencing. I need to compute the smallest enclosing quadrilaterals for a large sequence of irregular polygons (latitude/longitude value pairs) in order to approximately place a location in the right "polygon" with…
DroidOS
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Shortest path in a maze

There is a maze, which is nothing but made of $2$ parallel polylines, which looks like a zig-zag road. We have to find the shortest path between the entrance and exit. Any ideas on how to proceed? Does it involve dynamic programming? The maze can be…
V Shreyas
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Maximum Side of a Square Dissected into Rectangles

Suppose a $m \times m$ square can be dissected into $7$ rectangles such that no two rectangles have a common interior point and the side lengths of the rectangles form the set $\{1,2,3,4,5,6,7,8,9,10,11,12,13,14\}$. Find the maximum value of $m$. I…
Fawkes4494d3
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Voronoi average number of vertices $< 6$

My text says "the average number of vertices of the Voronoi cells is less than six". Then it creates the vertex "at infinity", connects the half-infinite edges to this vertex and shows the equation: $$(v + 1) - e + n = 2$$ where v = number of…
PeteUK
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Link and its Intersection

Let $K$ be a simplicial complex in $R^2$ such that $|K|$ is a simple polygon with inside. An internal edge $ab \in K$ is an edge such that both of its two endpoints a and b are NOT on the boundary of $|K|$. Prove or disprove that: link($ab$) =…
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Cover a polygon using a minimal set of rectangles

Given some polygon and rectangles all of a fixed height and width, how I can calculate the number and placement of the rectangles so that no point within or on the polygon is not contained within at least one rectangle. The rectangles are allowed to…
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Length of the voronoi diagram

Does there exist an algorithm for computing the length of the voronoi diagram of a set of points or just gives the intersection points of the voronoi diagram?
mrk
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Art Gallery Problem - is covering the edges enough?

The question is quite straight-forward but I can't seem to find the correct keywords to get my answer on the internet. For those who are not familiar with the problem, given a polygon P we are asked to find the minimum number of guards which…
John Katsantas
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