Computes distances to polygon edges and vertices and can check whether points are inside/outside.
This library is optimized to perform well with hundreds or thousands of polygons and thousands or millions of points.
Example timings (190 polygons, 1 M reference points, run on 12th Gen Intel i7-12700T at 4.6 GHz):
- distances to nearest edges: 320 ms
- distances to nearest vertices: 290 ms
- check whether points are inside or outside: 45 ms
$ pip install polygons - Python: 3.10 - 3.13
- Operating systems: Linux, macOS, and Windows
- Check whether points are inside or outside polygons
- Nearest distances to edges
- Nearest distances to vertices
If you use this tool in a program or publication, please acknowledge its author(s):
@misc{polygons, author = {Bast, Radovan}, title = {Polygons: Fast points-in-polygon test and distances to polygons}, month = {03}, year = {2025}, publisher = {Zenodo}, version = {v0.3.5}, doi = {10.5281/zenodo.3825616}, url = {https://doi.org/10.5281/zenodo.3825616} }import polygons # polygon_points is a list of lists # the library has been developed to perform # with very many polygons - this is just to have a simple example # in this example the polygons have the same number of points but there # is no restriction like this, this is only an example polygon_points = [ [(0.0, 0.0), (1.0, 0.0), (1.0, 1.0), (0.0, 1.0)], [(0.0, 2.0), (1.0, 2.0), (1.0, 3.0), (0.0, 3.0)], ] # the more points you compute in one go, the better # here using two points to make a simple example but if you have many points # then compute a thousand or a million in one go # so that the library can parallelize over the points points = [(0.5, 0.5), (0.5, -0.5)] # parameters for the tree construction: # - each tree node has 4 children nodes # - each leaf collects 4 edges # you can try different parameters and check the timing # they (should) have no effect on the results apart from timing num_edges_children = 4 num_nodes_children = 4 tree = polygons.build_search_tree( polygon_points, num_edges_children, num_nodes_children ) inside = polygons.points_are_inside(tree, points) print(inside) # [True, False] # indices are the indices of the nearest polygon vertices (counted # consecutively) indices, distances = polygons.distances_nearest_vertices(tree, points) print(indices) # [0, 0] print(distances) # [0.7071067811865476, 0.7071067811865476] distances = polygons.distances_nearest_edges(tree, points) print(distances) # [0.5, 0.5] indices, distances = polygons.distances_nearest_vertices( tree, [(0.6, 0.6), (0.5, -0.5)] ) print(indices) # [2, 0] print(distances) # [0.5656854249492381, 0.7071067811865476]- http://geomalgorithms.com/a03-_inclusion.html
- https://en.wikipedia.org/wiki/Point_in_polygon
- https://en.wikipedia.org/wiki/Binary_space_partitioning
Running the benchmark:
$ cargo test --release -- --ignored --nocapture Python interface inspired by https://github.com/dev-cafe/rustafarian.
Building and testing the Python interface:
$ maturin develop Social media preview generated using https://github.com/qrohlf/trianglify.