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。
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5|2v6W!e function FF=frft_PXJ(N,alpha);
|/K+tH %matrix
oK1"8k|Z % FF is the kernel matrix of fractional Fourier transform
- '& 4No % \copyright: zjliu
c$aTl9e % Author's email:
zjliu2001@163.com HPVW2Y0_N Ts=sqrt(2*pi/N); t=-(N-1)/2:(N-1)/2; t=t'; t=t*Ts;
n|`L>@aw, variance=N/2/pi; HH=zeros(N); HH(:,1)=1; HH(:,2)=2*t;
J{8_4s!Xt> for k=3:N;
jR<yV HH(:,k)=HH(:,k-1).*t*2-2*(k-2)*HH(:,k-2);
zh7#[#>t end
]eA< HH(:,1)=1/sqrt(sqrt(variance))*HH(:,1).*exp(-t.*t/2);
ldcYw@KQ for k=2:N;
7MIu- x| HH(:,k)=exp(-t.*t/2).*HH(:,k)/sqrt(2.^(k-1)*...
fF !Mmm" factorial(k-1)*sqrt(variance));
Gw3eO&X3i end
41 sClC" if mod(N,2)==1;
}m NP[L W=0:N-1; k=exp(-i*alpha*W); D=diag(k);
jSbO1 go# else
I,dH\]^h= W=0:N-2; W=cat(2,W,[N]); k=exp(-i*alpha*W); D=diag(k);
4Fhiac end
Kl. xe&t@j FF=Ts*HH*D*HH'*2;
zA [6rYXY % Reference:
<]I[|4J 7 % by 平先军.一种新的分数阶傅立叶变换快速算法.电子学报.
fhqc[@Y[ % 2001(3),Vol.29:406-408.
