KFFT

代码说明：

  计算离散傅里叶变换的一种快速算法，简称FFT。快速傅里叶变换是1965年由J.W.库利和T.W.图基提出的。采用这种算法能使计算机计算离散傅里叶变换所需要的乘法次数大为减少，特别是被变换的抽样点数N越多，FFT算法计算量的节省就越显著。(A computing discrete Fourier transform fast algorithm, referred to as FFT. Fast Fourier Transform in 1965 by the JW Cooley and TW Tuji Ti out. Using this algorithm enables a computer to calculate the number of multiplications needed for the discrete Fourier transform greatly reduced, especially sampling points N is transformed more and save FFT algorithm to calculate the amount of the more remarkable.)