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。
K"^cq~ bQj`g2eyM function FF=frft_PXJ(N,alpha);
fp tIc#4 %matrix
qy&\Xgn;GA % FF is the kernel matrix of fractional Fourier transform
z{/LX
\ % \copyright: zjliu
2qXo{C3 % Author's email:
zjliu2001@163.com [Xq<EEb Ts=sqrt(2*pi/N); t=-(N-1)/2:(N-1)/2; t=t'; t=t*Ts;
OEI3eizgH variance=N/2/pi; HH=zeros(N); HH(:,1)=1; HH(:,2)=2*t;
-%i #j> for k=3:N;
1lsLG+Rpxi HH(:,k)=HH(:,k-1).*t*2-2*(k-2)*HH(:,k-2);
:cdQ(O.m end
r@Nl 2 HH(:,1)=1/sqrt(sqrt(variance))*HH(:,1).*exp(-t.*t/2);
& +] x;K for k=2:N;
3(o7co-f HH(:,k)=exp(-t.*t/2).*HH(:,k)/sqrt(2.^(k-1)*...
1OP" 5f factorial(k-1)*sqrt(variance));
dk8y>uLr_ end
1 w 17L]4 if mod(N,2)==1;
]!J<,f7W W=0:N-1; k=exp(-i*alpha*W); D=diag(k);
l#ZyB| else
y{92L ym W=0:N-2; W=cat(2,W,[N]); k=exp(-i*alpha*W); D=diag(k);
cyBW0wV1 end
}k| g%H J FF=Ts*HH*D*HH'*2;
!-ZP*V3}h % Reference:
7IQqN&J % by 平先军.一种新的分数阶傅立叶变换快速算法.电子学报.
P#v^"}.Wd % 2001(3),Vol.29:406-408.
