fɔːɹ mˈoːɹ dʒˈɛnɚɹəl dˌiːvɪˈeɪʃənz fɹʌm sˌɜːkjʊlˈæɹᵻɾi ˈaɪ.ˈiː., wˌɛn wiː kænˈɑːt nᵻɡlˈɛkt ðə hˈaɪɚɹˈɔːɹdɚ tˈɜːmz ɪnðə tˈeɪlɚɹ ɛkspˈænʃən ʌv dʒˈeɪ, ˈiːɾə mˈeɪ biː ɛkspˈændᵻd ɪn ɐ fˈoːɹiɚ sˈɪɹiz, ˈiː.dʒˈiː.,
For more general deviations from circularity (i.e., when we cannot neglect the higher-order terms in the Taylor expansion of J ), η may be expanded in a Fourier series, e.g.,