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。
F[|aDj@q e D #twS function FF=frft_PXJ(N,alpha);
0Z[8d0 %matrix
.7zdA IKW % FF is the kernel matrix of fractional Fourier transform
QXT *O % \copyright: zjliu
b~; +E#[* % Author's email:
zjliu2001@163.com UD r@ Ts=sqrt(2*pi/N); t=-(N-1)/2:(N-1)/2; t=t'; t=t*Ts;
78+PG(Q_M variance=N/2/pi; HH=zeros(N); HH(:,1)=1; HH(:,2)=2*t;
U@?Ro enn for k=3:N;
HQ8;d9cGir HH(:,k)=HH(:,k-1).*t*2-2*(k-2)*HH(:,k-2);
4THGHS^ end
m m<rdo(` HH(:,1)=1/sqrt(sqrt(variance))*HH(:,1).*exp(-t.*t/2);
n|iO)L\9aB for k=2:N;
r(qU~re'
HH(:,k)=exp(-t.*t/2).*HH(:,k)/sqrt(2.^(k-1)*...
ddjaM / .E factorial(k-1)*sqrt(variance));
VJ(#FA2 end
Z4Qq#iHZR if mod(N,2)==1;
ZgI1Byf W=0:N-1; k=exp(-i*alpha*W); D=diag(k);
b jJ2 12 J else
n.xW"omN W=0:N-2; W=cat(2,W,[N]); k=exp(-i*alpha*W); D=diag(k);
g)k::k)<e end
tm}0kWx FF=Ts*HH*D*HH'*2;
-z4pI= % Reference:
rOy-6og % by 平先军.一种新的分数阶傅立叶变换快速算法.电子学报.
J4ltHk.| % 2001(3),Vol.29:406-408.
