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。
JP=Z Uu ti_u!kNv function FF=frft_PXJ(N,alpha);
TOT
PzB %matrix
.Q\\dESn" % FF is the kernel matrix of fractional Fourier transform
DeQDH5X" % \copyright: zjliu
3H8Al % Author's email:
zjliu2001@163.com tOg=zXm Ts=sqrt(2*pi/N); t=-(N-1)/2:(N-1)/2; t=t'; t=t*Ts;
==9ZFdf variance=N/2/pi; HH=zeros(N); HH(:,1)=1; HH(:,2)=2*t;
JAP (| for k=3:N;
J$[Q?8
ka HH(:,k)=HH(:,k-1).*t*2-2*(k-2)*HH(:,k-2);
f=_ g8+}h end
)I9aC~eAD HH(:,1)=1/sqrt(sqrt(variance))*HH(:,1).*exp(-t.*t/2);
z7=fDe
- for k=2:N;
80&D"" HH(:,k)=exp(-t.*t/2).*HH(:,k)/sqrt(2.^(k-1)*...
a%J /0'(d factorial(k-1)*sqrt(variance));
> oY^Gx end
}$aN Of %: if mod(N,2)==1;
7),*3c ') W=0:N-1; k=exp(-i*alpha*W); D=diag(k);
T$ c+m\j6 else
{D(,ft;s^ W=0:N-2; W=cat(2,W,[N]); k=exp(-i*alpha*W); D=diag(k);
!S,pRS+ end
_*`q(dY cf FF=Ts*HH*D*HH'*2;
ScJu_A f % Reference:
hqW$k w % by 平先军.一种新的分数阶傅立叶变换快速算法.电子学报.
_rjB c ;a % 2001(3),Vol.29:406-408.
