F(2)=4∑f(x)/x=4-11 f(1) 2时 =1/2 =0 f(2) (f(3) f(0) 3时,F3)=4∑(x如2=j-1- f(1) x=0 f(2) (f(3) 在N=4时,傅立叶变换以矩阵形式表示为 F(u)= Af(l) x1/ 2 ( (3) (2) (1) (0) (2) ( ) [1 1 1 1] 4 1 3 0 4 1 =             =  = − − − = f f f f F f x e jπ π u=2时 x , u=3时, 在N=4时，傅立叶变换以矩阵形式表示为 F(u)= =Af(x) 0 ( (3) (2) (1) (0) (3) ( ) [1 1 ] 4 3 / 2 1 3 0 4 1 =             =  = − − − = f f f f F f x e j j j π x x x y -1 1 j -j                         − − − − − − 0 1 0 1 1 1 1 1 1 1 1 1 1 1 1 1 4 1 j j j j