以DFT为例: X(k)=DFx(m)=∑x(m)W0≤k≤N-1 H=0 计算机运算时(编程实现): k=0X(0)=x(0W0+x(1)WN0+…+x(N-1-10 k=1X(1)=x(0X+x(1W+…+x(N-1)WX) (N-1)2 N个点 k=2X￥(2)=x(02+x(1)W2+…+x(N-1)WN k=N-1X(N-1)=x0+x()w+…+x(N-1)Wy-1 N次复乘,N-1次复加计算机运算时（编程实现）： k = 0 0 0 1 0 ( 1) 0 (0) (0) (1) ( 1)   −  = + + + − N N N N WN X x W x W  x k =1 01 11 ( 1) 1 (1) (0) (1) ( 1) N X x W x W x N W N N N   −  = + + + − k = 2 0 2 1 2 ( 1) 2 (2) (0) (1) ( 1) N X x W x W x N W N N N   −  = + + + − k = N −1 0 1 1 1 ( 1) 1 ( 1) (0) (1) ( 1) N N N N X N x W x W x N W N N N  −  − −  − − = + + + − N次复乘，N-1次复加 N个点 ( ) [ ( )] ( ) 0 1 1 0 = =    − − = X k DFT x n x n W k N N n nk N 以DFT为例：