def geometric_mean(points):
    """Gets centroid in a series of points

    Parameters
    ----------
    points : list of list of float
        List of (x, y) coordinates

    Returns
    -------
    tuple
        The centroid of a list of points
    """
    avg_x = sum([float(p[0]) for p in points]) / len(points)
    avg_y = sum([float(p[1]) for p in points]) / len(points)
    return (avg_x, avg_y)