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Computer Science Stack Exchange

Questions tagged [space-partitioning]

24 questions
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A key-value datastructure with fast (on average) member move and nearest neighbors search?

I have a 3 dimensional float key search space (say a simulation world). I want to keep my values (ints, agent ids) in a data structure that can perform nearest neighbors search (with search for N neighbors in a range surrounding a given key) as fast…
DuckQueen
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Randomly partition an rectangle into N smaller rectangles

I'm looking for an algorithm that can partition a rectangle into N smaller rectangles, at random. N will be small (on the order of 5-10 in most cases). It need not be uniformly at random, but at the very least, I'd like to avoid algorithms which…
philomory
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1 answer

Closest point in embedded simplicial complex

Suppose I have a simplicial $k$-complex $\mathcal S$ whose vertices are embedded in Euclidean space $\mathbb R^n$, for roughly $k< n\leq 6$. Examples include triangle mesh surfaces ($k=2$) embedded in $\mathbb R^3$ ($n=3$) and one-dimensional chains…
Justin Solomon
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5
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1 answer

Why does RAID-5 require an additional disk for parity blocks?

I know that RAID-5 consists of block-level striping across multiple disks, but using an additional parity-check block on each disk .. and that at least two disks are required for striping. And it's obvious that each parity block is specific to each…
user6039980
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5
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1 answer

Query all bounding boxes which contain a point

I'm looking for the most efficient spatial-indexing data-structure for storing and querying bounding boxes which contain individual points. The points represent 2D coordinates on a grid, while the bounding boxes represent regions of the grid. The…
jocopa3
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4
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Arrange objects in space so that the outline takes the least surface/volume

Imagine you have a number of 2-dimensional objects. The question is how to fit them all in a rectangular space in such a way that this rectangle takes the smallest area possible. On the below image you can see (more or less) what I mean: The…
alex
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Data structure to hold and retrieve points in a plane

Definition 1: Point $(x,y)$ is controlling point $(x',y')$ if and only if $x < x'$ and $y < y'$. Definition 2: Point $(x,y)$ is controlled by point $(x',y')$ if and only if $x' < x $ and $ y' < y$. I'm trying to come up with data structure to…
triple fault
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3
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Given a list of points on a sphere find the place for another point such that most space is covered?

Suppose I knew my current location as a geographical point (Lat/Lng) and had a standard radius to search (meters). Now given a list of previously searched geographical points as the centers of circles with the same standard radius that are nearby my…
sethmlarson
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Data Structure for k Nearest Neighbour Search in D dimension using only point cloud as query points

I have a point cloud of N points in D-dimensional space with periodic boundary conditions, where N can range from 500 to 10^8 and D can range from 1 to 20. The distribution of points varies wildly, from completely uniform to very clumped together,…
user51106
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Represent an octree as a binary tree of thrice the depth?

In an octree, each node has up to eight child nodes. This can be implemented with eight pointers per node that are set to null pointers if the child is not used. Another implementation uses a byte as bit-mask that stores which children are used and…
danijar
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Algorithm to cut a sphere in half with a plane and maximize the number of points on the sphere surface on one side of the plane

Consider a sphere with a coordinate system like the earth. There are $N$ points on its surface at random positions. For all the infinite planes that cuts the sphere exactly in half (i.e. the sphere's center is on the plane), given the set of…
Jamesits
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2
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2 answers

Tree structure that is like a quadtree/octree but splits a different number of times in each dimension?

I'm looking for a data structure that is like a quadtree where each level is a subdivision of the previous. However, unlike a quadtree I need the subdivision to occur a different number of times in the horizontal direction to the vertical direction.…
James Bedford
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Detecting non-airtight geometry

I have a finite region of 3D space that some (arbitrarily-shaped, concave) geometry occupies, and I need to identify whether that geometry forms a closed 3D volume (or multiple disjoint closed 3D volumes). That is, I need to identify if, and where,…
Alex Barilaro
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Data Structure for finding all bounding boxes that overlap or are contained in a given bounding box

I am looking for a data structure that needs to have very fast and accurate queries to solve the following: The input: A set of 3 Dimensional axis-aligned bounding boxes B A separate 3D axis aligned bounding box b' The output: A list of bounding…
yo76yo
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balanced partitioning of nonconvex area between multiple agents in a grid world

In the original art gallery problem, there is a non-convex area provided and one has to divide it into regions based on infinite visibility of guards. We assume an unlimited number of guards. However, suppose we only have n number of guards with…
user_1_1_1
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