error_functions.py 文件源码

def _eval_rewrite_as_li(self, z):
        if isinstance(z, log):
            return li(z.args[0])
        # TODO:
        # Actually it only holds that:
        #  Ei(z) = li(exp(z))
        # for -pi < imag(z) <= pi
        return li(exp(z))