中文说明：单频干扰陷波器源码。自适应陷波器，与一般陷波器比较，有两大优点：（1）能够自适应地准确跟踪干扰频率。（2）容易控制带宽.
English Description：
Single frequency interference notch filter source code. Compared with the conventional notch filter, the adaptive notch filter has two advantages: (1) it can track the interference frequency adaptively and accurately. (2) Easy to control bandwidth