hyper.py 文件源码

def _eval_rewrite_as_Sum(self, ap, bq, z):
        from sympy.functions import factorial, RisingFactorial, Piecewise
        n = C.Dummy("n", integer=True)
        rfap = Tuple(*[RisingFactorial(a, n) for a in ap])
        rfbq = Tuple(*[RisingFactorial(b, n) for b in bq])
        coeff = Mul(*rfap) / Mul(*rfbq)
        return Piecewise((C.Sum(coeff * z**n / factorial(n), (n, 0, oo)),
                         self.convergence_statement), (self, True))