生成原始信号，做出FFT模值、幅度频率曲线、相位频率曲线 不是我写的程序，是别人下载的程序却无法运行，我帮他改好的(The original signal is generated, and the FFT modulus, amplitude frequency curve and phase frequency curve are made I did not write the program, the program is downloaded by others, but can