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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def get_points_within_r(center_points, target_points, r):
 r"""Get all target_points within a specified radius of a center point. All data must be in same coordinate system, or you will get undetermined results. Parameters center_points: (X, Y) ndarray location from which to grab surrounding points within r target_points: (X, Y) ndarray points from which to return if they are within r of center_points r: integer search radius around center_points to grab target_points Returns ------- matches: (X, Y) ndarray A list of points within r distance of, and in the same order as, center_points """

    tree = cKDTree(target_points)
    indices = tree.query_ball_point(center_points, r)
    return tree.data[indices].T