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pythonscipyspatialconvex-hull

Check if points lies inside a convex hull

I am making a convex hull using the scipy.spatial package http://docs.scipy.org/doc/scipy/reference/generated/scipy.spatial.ConvexHull.html#scipy.spatial.ConvexHull

I've tried searching, but have yet to know if there is an easy way to find if any point (latitude/longitude) lies inside the convex hull. Any suggestions?

Solution

  • The method that I've used before is using the Path class matplotlib. This has a contains_point method which does exactly that. As well as a contains_points which allows you to query an array of points.

    To use this you would do

    from scipy.spatial import ConvexHull
from matplotlib.path import Path

hull = ConvexHull( points )

hull_path = Path( points[hull.vertices] )

print hull_path.contains_point((1,2)) # Is (1,2) in the convex hull?