@classmethod
    def eval(cls, n, m, theta, phi):
        n, m, th, ph = [sympify(x) for x in (n, m, theta, phi)]

        if m.is_positive:
            zz = (Ynm(n, m, th, ph) + Ynm_c(n, m, th, ph)) / sqrt(2)
            return zz
        elif m.is_zero:
            return Ynm(n, m, th, ph)
        elif m.is_negative:
            zz = (Ynm(n, m, th, ph) - Ynm_c(n, m, th, ph)) / (sqrt(2)*I)
            return zz
dataset/ETHPy150Open sympy/sympy/sympy/functions/special/spherical_harmonics.py/Znm.eval/original