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Oct 3, 2024 · A very fast 2D concave hull algorithm. Credits goes to: https://github.com/mapbox/concaveman. https://github.com/sadaszewski/concaveman-cpp. Online document: https://concave-hull.readthedocs.io/en/latest/.
- Overview
- Install
- Usage
A very fast 2D concave hull algorithm.
Credits goes to:
•https://github.com/mapbox/concaveman
•https://github.com/sadaszewski/concaveman-cpp
via pip from source
Or (you can build wheels for later reuse by pip wheel git+https://github.com/cubao/concave_hull.git)
Signature:
•concavity is a relative measure of concavity. 1 results in a relatively detailed shape, Infinity results in a convex hull. You can use values lower than 1, but they can produce pretty crazy shapes.
•length_threshold: when a segment length is under this threshold, it stops being considered for further detalization. Higher values result in simpler shapes.
(document from https://github.com/mapbox/concaveman)
Jul 30, 2019 · Here is a github repo on finding the concave hull for a set of points using python. My recommendation to you is the following. Create a set of points using the endpoints of each line. Then use the linked to code to generate a concave hull for these points, with some guess for the value of alpha.
Concavity is a small python module that implements a concave hull algorithm following Moreira, Adriano & Santos, Maribel. (2007) [1], based on k-nearest-neighbors. It also implements an algorithm for concave and convex vertices detection on a polygon's exterior and interiors, and plot them for EDA.
R has the alphahull module, which has excellent documentation on computing alpha shapes. Also check this detailed background on alpha shapes. If you only want to compute convex/concave hulls, check out lasboundary, part of lastools, it scales well and can handle millions of input points.
Sep 28, 2024 · It is a "manual" code, and it used the Delaunay function. The code template I took from here: https://deeplearning.lipingyang.org/wp-content/uploads/2019/07/Drawing-Boundaries-In-Python.pdf. Not ideal, but it works better. —————. I still try to build a concave hull algorithm implementation.
People also ask
What is concave Hull Python?
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Apr 16, 2021 · Generate an Alpha Shape (α = 0.0) (Convex Hull) Every convex hull is an alpha shape, but not every alpha shape is a convex hull. When the alphashape function is called with an alpha parameter of 0, a convex hull will always be returned.
