此程序为c++实现频谱分析，可用于对傅里叶变换进行分析-This procedure for the c++ to achieve spectral analysis, Fourier transform can be used to analyze

实现了一个复杂文件的读入，并显示频谱图。需要注意的是，纵坐标需要控制长度。(To achieve a complex file read, and show the spectrum. Note that the ordinate requires control of length.)