remove duplicates from an array of lon / lat points

def remove_duplicate_lonlat(lon, lat):
    """
    remove duplicates from an array of lon / lat points
    """

    a = np.ascontiguousarray(np.vstack((lon, lat)).T)
    unique_a = np.unique(a.view([('', a.dtype)]*a.shape[1]))
    llunique = unique_a.view(a.dtype).reshape((unique_a.shape[0], a.shape[1]))

    lon1 = llunique[:,0]
    lat1 = llunique[:,1]

    return lon1, lat1