inpoly-python | A fast 'point-in-polygon ' test for Python

inpoly-python is a Python library. inpoly-python has no bugs, it has no vulnerabilities, it has build file available and it has low support. However inpoly-python has a Non-SPDX License. You can install using 'pip install inpoly-python' or download it from GitHub, PyPI.

A fast 'point(s)-in-polygon' routine for Python. INPOLY returns the "inside/outside" status for a set of vertices VERT and a general polygon (PSLG) embedded in the two-dimensional plane. General non-convex and multiply-connected polygonal regions can be handled. INPOLY is based on a 'crossing-number' test, counting the number of times a line extending from each point past the right-most region of the polygon intersects with the polygonal boundary. Points with odd counts are 'inside'. A simple implementation requires that each edge intersection be checked for each point, leading to (slow) O(N*M) overall complexity. This implementation seeks to improve these bounds. Query points are sorted by y-value and candidate intersection sets are determined via binary-search. Given a configuration with N test points, M edges and an average point-edge 'overlap' of H, the overall complexity scales like O(M*H + M*LOG(N) + N*LOG(N)), where O(N*LOG(N)) operations are required for the initial sorting, O(M*LOG(N)) operations are required for the set of binary-searches, and O(M*H) operations are required for the actual intersection tests. H is typically small on average, such that H << N. Overall, this leads to fast O((N+M)*LOG(N)) complexity for average cases.