spline approximation

• 样条逼近,样条函数近似

spline approximation的用法和样例：

例句

1. While for the sinusoidal approximation method, a detail derivation of the amplitude of each sinusoidal function is re-derived for completeness.
   为完整性，文中亦详细推导正弦函数近似法中各个频率之振幅。