快速傅立叶变换的matlab算法实现。（是一个按照时间抽取的基-2快速傅里（基-2 FFT-DIT）。输入倒位序，输出自然顺序。-Fast Fourier Transform algorithm matlab. (Which is a time of extraction in accordance with the base-2 Fast Fu-ri (base-2 FFT-DIT). Enter the inversion sequence, the output of natural order.