pysal.lib.cg.alpha_shape_auto

pysal.lib.cg.alpha_shape_auto(xys, step=1, verbose=False)[source]

Computation of alpha-shape delineation with automated selection of alpha. …

This method uses the algorithm proposed by Edelsbrunner, Kirkpatrick & Seidel (1983) to return the tightest polygon that contains all points in xys. The algorithm ranks every point based on its radious and iterates over each point, checking whether the maximum alpha that would keep the point and all the other ones in the set with smaller radii results in a single polygon. If that is the case, it moves to the next point; otherwise, it retains the previous alpha value and returns the polygon as shapely geometry.

Returns:
poly : shapely.Polygon

Tightest alpha-shape polygon containing all points in xys

References

Edelsbrunner, H., Kirkpatrick, D., & Seidel, R. (1983). On the shape of
a set of points in the plane. IEEE Transactions on information theory, 29(4), 551-559.