快速傅立叶变换（FFT）算法实现 将DFT算法与FFT算法计算时间进行比较，分析二者的效率和精确差异。-Fast Fourier Transform (FFT) algorithm to DFT algorithm and FFT algorithm for computing time to carry out comparative analysis between the two differences in the efficiency and precision.

实现dft基本功能。对频率分辨率有特殊说明，希望对您有帮助。-The realization of the basic functions of dft. Frequency resolution of special note, I hope for your help.