转载一个实现分数傅立叶变换的matlab程序,作者信息在程序中有。
L4y4RG/SJ: h>OfOx/{q9 function FF=frft_PXJ(N,alpha);
p0<\G %matrix
/J6rv(( % FF is the kernel matrix of fractional Fourier transform
N_[*H % \copyright: zjliu
!f&g-V % Author's email:
zjliu2001@163.com 001FmiV Ts=sqrt(2*pi/N); t=-(N-1)/2:(N-1)/2; t=t'; t=t*Ts;
vTw>JNVI variance=N/2/pi; HH=zeros(N); HH(:,1)=1; HH(:,2)=2*t;
vn"{I&L+w0 for k=3:N;
WbqWG^W HH(:,k)=HH(:,k-1).*t*2-2*(k-2)*HH(:,k-2);
d)f :)Ew end
#],&>n7' HH(:,1)=1/sqrt(sqrt(variance))*HH(:,1).*exp(-t.*t/2);
#"iu|D for k=2:N;
t" Z6[XG HH(:,k)=exp(-t.*t/2).*HH(:,k)/sqrt(2.^(k-1)*...
j^rIH#V factorial(k-1)*sqrt(variance));
`~CQU end
q;>7*Y& if mod(N,2)==1;
/{--+
C W=0:N-1; k=exp(-i*alpha*W); D=diag(k);
!^Y(^RS@ else
=h73s0] W=0:N-2; W=cat(2,W,[N]); k=exp(-i*alpha*W); D=diag(k);
tS8u end
B%+T2=&$7 FF=Ts*HH*D*HH'*2;
ax5<#3__ % Reference:
MfQ?W`Kop % by 平先军.一种新的分数阶傅立叶变换快速算法.电子学报.
M%;hB*9 % 2001(3),Vol.29:406-408.