What's an efficient way to find if a point lies in the convex hull of a point cloud?

I have a point cloud of coordinates in numpy. For a high number of points, I want to find out if the points lie in the convex hull of the point cloud.

I tried pyhull but I cant figure out how to check if a point is in the ConvexHull:

hull = ConvexHull(np.array([(1, 2), (3, 4), (3, 6)]))
for s in hull.simplices:
    s.in_simplex(np.array([2, 3]))

raises LinAlgError: Array must be square.