def METHOD_NAME():
    """Test period finding in the direction"""
    arr = np.concatenate((np.arange(5), np.arange(5))).astype(float)
    assert num.find_direction_period(arr) == 5
    arr[1] = np.nan
    arr[7] = None
    assert num.find_direction_period(arr) == 5
    arr = np.array([1, 2, 3, 1, 2, 1, 2, 3])
    assert num.find_direction_period(arr) is None
    arr = np.ones(10)
    assert num.find_direction_period(arr) is np.inf