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。
(w#t V* }04mJY[ function FF=frft_PXJ(N,alpha);
xI1{Wo*2C} %matrix
A$r$g\5+ % FF is the kernel matrix of fractional Fourier transform
:^WF%X % \copyright: zjliu
4")`}T % Author's email:
zjliu2001@163.com H)i|?3Ip Ts=sqrt(2*pi/N); t=-(N-1)/2:(N-1)/2; t=t'; t=t*Ts;
&}[P{53sr variance=N/2/pi; HH=zeros(N); HH(:,1)=1; HH(:,2)=2*t;
'St6a* for k=3:N;
:u./"[G HH(:,k)=HH(:,k-1).*t*2-2*(k-2)*HH(:,k-2);
(z>t 4(%\ end
>9rZVNMU HH(:,1)=1/sqrt(sqrt(variance))*HH(:,1).*exp(-t.*t/2);
7jIBE for k=2:N;
^L5-2;s<U' HH(:,k)=exp(-t.*t/2).*HH(:,k)/sqrt(2.^(k-1)*...
n'v\2(&uYN factorial(k-1)*sqrt(variance));
UL-_z++G end
VO8rd>b4 if mod(N,2)==1;
R8k4?_W?T W=0:N-1; k=exp(-i*alpha*W); D=diag(k);
HB8s[]A:D else
Nw'03Jzx_ W=0:N-2; W=cat(2,W,[N]); k=exp(-i*alpha*W); D=diag(k);
K\rQb end
A$3Rbn}" FF=Ts*HH*D*HH'*2;
m9oOH5@K~ % Reference:
-1,0hmn=+ % by 平先军.一种新的分数阶傅立叶变换快速算法.电子学报.
RC/ 3\' % 2001(3),Vol.29:406-408.