A quadtree is a geometric data structure for storing points in two-dimensional space. Quadtrees recursively partition a space into four quadrants.
Questions tagged [quadtree]
380 questions
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votes
2 answers
How to find unique pairs of a quad tree?
I am using a quad tree data structure to find nearby objects on a 2D plane. I have already implemented a working quad tree which returns an array for each object including all of it's neighbours. The problem is, I need each unique pair of objects…
Jacob
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1 answer
How to improve performance of QuadTree code to prevent program from freezing
I'm simulating the collision of two star clusters, so basically doing an N-body problem, in C++. I'm using the Barnes-Hut method to help do this. I've written my QuadTree code and the main code to run the simulation and it works up until the…
Zachary
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1 answer
RecursiveFree Function - Warning: initialization from incompatible pointer type [-Wincompatible-pointer-types]
I have a function which recursively frees:
#include "treeStructure.h"
void destroyTree (Node* p)
{
if (p==NULL)
return;
Node* free_next = p -> child; //getting the address of the following item before p is freed
free (p);…
anon2000
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1 answer
OCaml Pathfinding in Quadtree maze
I have a quadTree type defined by that :
type 'a quadtree =
| Empty
| Leaf of 'a
| Node of 'a quadtree * 'a quadtree * 'a quadtree * 'a quadtree;;
Rooms defined by
type room = {
n : bool;
e : bool;
s : bool;
w : bool;
ps : coord;
exit :…
Victor Fanton
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2 answers
How to store a bmp file in a QuadTree in C++?
I would like to read and store a BMP file in a QuadTree:
An example of the BMP file would be:
P1
4 4
1 0 1 1
0 1 0 0
1 1 0 0
1 1 0 0
and the structure of the QuadTree I have thought of is:
struct QuadTreeNode{
int size;
struct QuadTreeNode…
Wryfyng
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votes
1 answer
When representing 2^n x 2^n matrices using quadtrees
I've just found the definition on my textbook and can't imagine what nexp is supposed to do/mean:
data (Eq a, Show a) => QT a = C a | Q (QT a) (QT a) (QT a) (QT a)
deriving (Eq, Show)
data (Eq a, Num a, Show a) => Mat a = Mat {
nexp ::…
gremo
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Which data structure should I use to store large 10,000 data set and do fastest search ,and take least memory?
*Suppose I have 10,000 circle(x,y,r) values , and i want to find a point (p1,p2) lies in which circle , to get fastest response for this query what data structure should i use to store those 10,000 circle data.
It is a static data ,means one time…
SK17
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1 answer
Efficient quadtree implementation in python
For a project I'm working on I'm trying to write some code to detect collisions between non-point particles in a 2D space. My goal is to try to detect collision for a few thousand particles at least a few times per time step which I know is a tall…
John Chabot
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1 answer
Flipping QuadTree in recursive abstract code
I'm trying to flip a quad tree about the vertical axis recursively, but without using a particular PL. In which case I've written the following, but I'm 100% it's not actually good, and I can't quite sure I understand it as well.
flip(quadtree) {
…
kx5
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1 answer
2d space indexing that supports efficient adding and removing static circular regions
I need to quickly set all pixels in a circle (x0,y0,r) to solid or empty on a big, per-pixel map. Like in worms or liero game when you blow up terrain with a bomb.
I considered quad tree and simple 2d array, but quad tree seems bad for…
ajuc
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2 answers
How do tree searches deal with edge errors in nearest-neighbor searches?
Concerning tree searching algorithms, particularly quad-tree and r-tree, how do they account for edge errors when finding nearest neighbors. I'm not good at explaining this with words so I made some pictures.
For the picture the input coordinate to…
wowohweewah
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1 answer
Having issue creating recursive constructor
I'm trying to build Quad-tree which receive array of points and split them into 4 cells. those 4 cells(cell1...cell4) are suppose to be created recursively but it doesn't works.
What I'm doing wrong? wasted all day trying fix it.
I erased some basic…
Dima B
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efficient C++ template implementation for 2D range queries
I need to store custom point objects (getX() and getY() are provided) in an efficient way to perform range queries. So i was looking for templated implementations of quadtree, kd-tree or similar. For example like this:…
the_ducky
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1 answer
Visualising a QuadTree in Java
I am trying to visualise my QuadTree in Java but I can't seem to get the positioning right. Basically, I want to recursively subdivide the canvas into rectangles if a node exists in the tree for that area. Here is what I have currently:
private…
Jonno_FTW
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presort data for balanced quadtree
The PMR Rectangle Quadtree is a quadtree which has an list of (Rectangle) objects in each leaf. This is called a bucket.
The structure of this quadtree is dependent on the order of inserting the elements.
The inventor of that quadtree proposed to…
AlexWien
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