Since any approximations, such as numerical Laplace inversion, backward differentiation formula, nonlinear model of switch, do not exist, the new algorithms are accurate.

• 由于该方法不存在任何极限近似问题（数值拉普拉斯反变换法，后向差分法，非线性开关模型法等），因而它是一种精确计算方法。