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。
?'MkaG0g %R c#/y function FF=frft_PXJ(N,alpha);
2 ?t@<M ] %matrix
@Z~YFnEJi % FF is the kernel matrix of fractional Fourier transform
>&P M' k % \copyright: zjliu
2LtDS?)@ % Author's email:
zjliu2001@163.com _ nMd Ts=sqrt(2*pi/N); t=-(N-1)/2:(N-1)/2; t=t'; t=t*Ts;
\) ~d,M}kK variance=N/2/pi; HH=zeros(N); HH(:,1)=1; HH(:,2)=2*t;
PXMd=,} for k=3:N;
E )_n?>Ar HH(:,k)=HH(:,k-1).*t*2-2*(k-2)*HH(:,k-2);
d?*] /ZiR end
F/ s
n"2 HH(:,1)=1/sqrt(sqrt(variance))*HH(:,1).*exp(-t.*t/2);
, _e [P for k=2:N;
PAYw:/(P HH(:,k)=exp(-t.*t/2).*HH(:,k)/sqrt(2.^(k-1)*...
Ss>pNH@ c factorial(k-1)*sqrt(variance));
8_('[89m end
# DUfEZ if mod(N,2)==1;
duY?LJ @g W=0:N-1; k=exp(-i*alpha*W); D=diag(k);
4Hj)Av <O( else
z{rV |vQ W=0:N-2; W=cat(2,W,[N]); k=exp(-i*alpha*W); D=diag(k);
GT P'js end
%F 2h C
x FF=Ts*HH*D*HH'*2;
7?Wte&C];p % Reference:
H9*k(lnz` % by 平先军.一种新的分数阶傅立叶变换快速算法.电子学报.
NU=ru/ % 2001(3),Vol.29:406-408.
