说明：  在FFT后信号的频率往往与谱线不相重合，而在两条谱线之间。为了要求得信号的频率、幅值和初始相角，必须要使用修正法来完成。这里给出一种修正法。
(After the signal in the FFT frequency spectrum often do not coincide, and in between the two lines. Request for a signal frequency, amplitude and initial phase angle, we must use to complete the Amendment Act. Here are a Amendment Act.)