QuadTrees

A PHP implementation of the Point QuadTree data structure

This uses a Generator for the search() method, returning a single result for each "iteration" or call to current(), so it requires PHP >= 5.5. The main purpose of this implementation is to show an example of a genuine use case for recursive generators.

The /examples folder contains a couple of examples to demonstrate its use:

citySearch.php

allows a search on a defined bounding box, and will display a list of cities that fall within that bounding box

usage:

 php citySearch.php <latitude> <longitude> <width> <height>

 latitude   Latitude of the centre point of the bounding box
              (as a floating-point value in degrees, positive values
              for East, negative for West)
 longitude  Longitude of the centre point of the bounding box
              (as a floating-point value in degrees, positive values
              for North, negative for South)
 width      Width of the bounding box 
              (as a floating-point value in degrees)
 height     Height of the bounding box
              (as a floating-point value in degrees)

Data for the list of cities is from geonames.org, licensed under a Creative Commons Attribution 3.0 License, and provided "as is" without warranty or any representation of accuracy, timeliness or completeness.

lunarLandingSearch.php

allows a search on a defined bounding box, and will display a list of moon landings that fall within that bounding box

usage:

 php lunarLandingSearch.php <latitude> <longitude> <width> <height>

 latitude   Latitude of the centre point of the bounding box
              (as a floating-point value in degrees, positive values
              for East, negative for West)
 longitude  Longitude of the centre point of the bounding box
              (as a floating-point value in degrees, positive values
              for North, negative for South)
 width      Width of the bounding box 
              (as a floating-point value in degrees)
 height     Height of the bounding box
              (as a floating-point value in degrees)

MarkBaker/GeneratorQuadTrees

QuadTrees