Exemplo n.º 1
0
    def _eval_apply(self, arg):
        arg = Basic.sympify(arg)

        if isinstance(arg, Basic.Number):
            if isinstance(arg, Basic.NaN):
                return S.NaN
            elif isinstance(arg, Basic.Zero):
                return S.Zero
            elif arg.is_negative:
                return -self(-arg)
        else:
            i_coeff = arg.as_coefficient(S.ImaginaryUnit)

            if i_coeff is not None:
                return S.ImaginaryUnit * Basic.tanh(i_coeff)
            else:
                pi_coeff = arg.as_coefficient(S.Pi)

                if pi_coeff is not None:
                    if pi_coeff.is_integer:
                        return S.Zero
                    elif isinstance(pi_coeff, Basic.Rational):
                        cst_table = {
                           #2 : S.ComplexInfinity,
                            3 : Basic.sqrt(3),
                            4 : S.One,
                            6 : 1 / Basic.sqrt(3),
                        }

                        try:
                            result = cst_table[pi_coeff.q]

                            if (2*pi_coeff.p // pi_coeff.q) % 4 in (1, 3):
                                return -result
                            else:
                                return result
                        except KeyError:
                            pass

                coeff, terms = arg.as_coeff_terms()

                if coeff.is_negative:
                    return -self(-arg)