fagan2888 / pyqtree

A pure Python quad tree spatial index for GIS or rendering usage

Pyqtree

Pyqtree is a pure Python spatial index for GIS or rendering usage. It stores and quickly retrieves items from a 2x2 rectangular grid area, and grows in depth and detail as more items are added. The actual quad tree implementation is adapted from Matt Rasmussen's compbio library and extended for geospatial use.

Platforms

Python 2 and 3.

Dependencies

Pyqtree is written in pure Python and has no dependencies.

Installing It

Installing Pyqtree can be done by opening your terminal or commandline and typing:

pip install pyqtree

Alternatively, you can simply download the "pyqtree.py" file and place it anywhere Python can import it, such as the Python site-packages folder.

Example Usage

Start your script by importing the quad tree.

from pyqtree import Index

Setup the spatial index, giving it a bounding box area to keep track of. The bounding box being in a four-tuple: (xmin, ymin, xmax, ymax).

spindex = Index(bbox=(0, 0, 100, 100))

Populate the index with items that you want to be retrieved at a later point, along with each item's geographic bbox.

# this example assumes you have a list of items with bbox attribute
for item in items:
    spindex.insert(item, item.bbox)

Then when you have a region of interest and you wish to retrieve items from that region, just use the index's intersect method. This quickly gives you a list of the stored items whose bboxes intersects your region of interests.

overlapbbox = (51, 51, 86, 86)
matches = spindex.intersect(overlapbbox)

There are other things that can be done as well, but that's it for the main usage!

More Information:

• Home Page
• API Documentation

License:

This code is free to share, use, reuse, and modify according to the MIT license, see LICENSE.txt.

Credits:

• Karim Bahgat (2015)
• Joschua Gandert (2016)

Changes

0.25.0 (2016-06-22)

• Misc user contributions and bug fixes

0.24.0 (2015-06-18)

• Previous stable PyPI version.