中文说明：自己编写的伯德图、尼奎斯特图、根轨迹图的matlab绘图程序，虽然小、简单，却很实用。便于大家教学中分析习题。
English Description：
The MATLAB drawing program of Bode diagram, Nyquist chart and root locus chart is small and simple, but it is very practical. It is convenient for everyone to analyze exercises in teaching.