def ellipticity2phi_gamma(e1, e2):
    """
    :param e1: ellipticity component
    :param e2: ellipticity component
    :return: angle and abs value of ellipticity
    """
    phi = np.arctan2(e2, e1)/2
    gamma = np.sqrt(e1**2+e2**2)
    return phi, gamma
:param e1: ellipticity component
    :param e2: ellipticity component
    :return: angle and abs value of ellipticity