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Questions tagged [quadtree]

A quadtree is a geometric data structure for storing points in two-dimensional space. Quadtrees recursively partition a space into four quadrants.

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How to handle duplicate points for R-trees and Quad trees?

I am looking at implementing a quad tree and r-tree data structures to test some ideas on dealing with distribution of 2 dimension points. My question is, how do these algorithms handle duplicate points? Or what are some techniques for handling…
Stefan Orr
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Split a node in a Quadtree

I'm implementing an immutable Quadtree in Scala and I can't understand what happens/when to split a node. These are my main references: Article 1, Article 2 and a third one I can't find now. I understand these 3 key points of a quadtree: A node…
ColOfAbRiX
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Cost/Benefit of Reverse Lookup in Quadtree Implementation

I recently wrote a point quadtree implementation, in which points are inserted based on (x, y) coordinates. Each point has a unique point_id. It has no reverse lookup right now – if you want to find a point, you need to pass coordinates. Are there…
David K.
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Quad Tree Implementation Operator++

I was wondering how you can implement an operator++ for a quad tree. I know that I have to go to the farthest child of the tree and then go to right.But not sure how to though. Any help would be appreciated. Thank You!
Daniel Choi
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Collision detection in R

I have a matrix of positions returned from any of the igraph layouts, e.g., layout=layout.fruchterman.reingold(g) This just has a set of points: [,1] [,2] [1,] 22.0952841 -25.0292619 [2,] 14.0612662 13.0353858 [3,] …
SOUser
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How to efficiently insert non-point objects into a quadtree

I'm trying to create a Quadtree structure in python for detecting collisions amongst polygons, and I've gotten pretty far (see end of the post). However, I realized that this structure only works for points, because I'm deciding which leaf to put…
nathan lachenmyer
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find area of a square recursively

I have a big square, which is made of small square-tiles of fixed size. The area of these small square-tiles are known. One of the tile is shown on the upper left corner. Now, Each square can be broken down into 4 subsquares. And each square has a…
Sounak
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KD-Tree on secondary memory?

I know some of the range searching data structure, for example kd-tree, Range tree and quad-tree. But all the implementation is in memory, how can I implementation them on secondary memory with high performance I/O efficiency? Here is the…
Zhao Yuhao
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Terrain LOD Camera Moving Crack

I have a grid based terrain and a quadtree for lod. In one simulation step i do the following: handle input. update matrices. build quadtree (view frustum culling, distance check). close cracks. copy enabled points to the vertex array. draw vertex…
Meldryt
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maximum recursion depth exceeded when inserting points into a quadtree using Python (dying looking for the bug)

I am trying to build a point region quadtree which stores points on a 2D map with Python, but when I try to insert two points which are close (not too close) to each other, I run into an error: RuntimeError: maximum recursion depth exceeded in cmp.…
Gordon Vanderbilt
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Recursive algorithm to return nested structure of a recursive QuadTree

I've been using this recurivse Quadtree from http://www.astroml.org/book_figures/chapter2/fig_quadtree_example.html on some data. But I now need a nested representation of the structure of the result. The structure is something…
James
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Syntax error on confusing compound Python statement

I'm try to run a quadtree example (first bit of code on that page) from pygame but am getting a syntax error on a very confusing line: in_nw = item.left <= cx and item.top <= cy The syntax error points at the second equals sign in the…
Airuno2L
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XY coordinates to quadtree in Javascript

I want to convert Converts tile XY coordinates into a QuadKey at a specified level of detail. I need to do this in Javascript. To Illustrate the problematic you will find an exact description here:…
Simon S.
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Implementing Insertion/Deletion/QueryRange in a Region-Quad tree?

When you're using a quad tree to store regions instead of just points, how exactly should your implementation change? I can't find a good source code example on the web of how one might implement a PR-QuadTree. The only examples I can find are of…
kjh
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quadtree decomposition of wavelet coefficients

After retrieving image coeffients (both approximate and detailed) in wavelet decomposition, i want quadtree structure for appoximate and detailed coefficients. but every time i am getting same error. Please help. I tried to make it power of 3…
TG29
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