quadtree-py

Quadtree is an essential data structure in the realm of GIS (Geographic Information System) which is able to build spatial index, perform spatial analysis, and compress data.

The visualization of quadtree is displayed as following:

Usage

from quadtree import QuadTree, Bounds, Point
import json

if __name__ == '__main__':
    my_tree = QuadTree(Bounds(0, 0, 400, 400), max_objects=4, max_level=5)
    # get point data from json file
    with open('path/to/json/example_data.json', 'r') as f:
        json_data = json.loads(f.read())
        point_set = json_data['data']
    # insert points
    for point in point_set:
        my_tree.insert(Point(point['x'], point['y'], point['value']))   
    # visualize quadtree
    my_tree.visualize()
    # retrieve objects that may collide with given boundingbox
    objects = my_tree.retrieve(Bounds(200, 200, 50, 50))
    # retrive objects that intersects with provided boundingbox
    objects_intersects = my_tree.retrieve_intersections(Bounds(200, 200, 50, 50))
    # retrieve nearest neighbors
    nearest_neighbors = my_tree.nearest_neighbors(Point(225, 225), radius=25, max_num=20)

TODO

• visualization
• nearest neighbors
• spatial analysis
  • kernel density estimation (KDE)
  • spatial clustering

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