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。
e "_"vbk R Kk" function FF=frft_PXJ(N,alpha);
VjTAN= %matrix
sT1j F3 % FF is the kernel matrix of fractional Fourier transform
<2)v9c % \copyright: zjliu
7'UWRRsxUF % Author's email:
zjliu2001@163.com _IKQ3 6= Ts=sqrt(2*pi/N); t=-(N-1)/2:(N-1)/2; t=t'; t=t*Ts;
a71}y;W variance=N/2/pi; HH=zeros(N); HH(:,1)=1; HH(:,2)=2*t;
)"~=7)~<^ for k=3:N;
4K #^dJnC HH(:,k)=HH(:,k-1).*t*2-2*(k-2)*HH(:,k-2);
Y[,U_GX/R end
jl@K!=q HH(:,1)=1/sqrt(sqrt(variance))*HH(:,1).*exp(-t.*t/2);
4 Q&mC" for k=2:N;
y`+<X{V5L HH(:,k)=exp(-t.*t/2).*HH(:,k)/sqrt(2.^(k-1)*...
C~_q^ fXJt factorial(k-1)*sqrt(variance));
05 g?jV end
>I: 9'"` if mod(N,2)==1;
@`2ozi~lO W=0:N-1; k=exp(-i*alpha*W); D=diag(k);
cJV!> 0ua else
4ioN A/E W=0:N-2; W=cat(2,W,[N]); k=exp(-i*alpha*W); D=diag(k);
.m'N7`VB end
]E..43 FF=Ts*HH*D*HH'*2;
KM@`YV_"g % Reference:
|{!Ns +' % by 平先军.一种新的分数阶傅立叶变换快速算法.电子学报.
v/(__xN`B % 2001(3),Vol.29:406-408.
