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。
(P|[< Sd ;'7(gAE function FF=frft_PXJ(N,alpha);
Z`S# > o %matrix
|7|S>h^ % FF is the kernel matrix of fractional Fourier transform
=:]ps<Qx % \copyright: zjliu
53i]Q;k [ % Author's email:
zjliu2001@163.com ;{ifLI0# Ts=sqrt(2*pi/N); t=-(N-1)/2:(N-1)/2; t=t'; t=t*Ts;
:PO./IBX variance=N/2/pi; HH=zeros(N); HH(:,1)=1; HH(:,2)=2*t;
%O \@rws for k=3:N;
.t "VsY| HH(:,k)=HH(:,k-1).*t*2-2*(k-2)*HH(:,k-2);
6
VEB2F end
/v
8"i^;} HH(:,1)=1/sqrt(sqrt(variance))*HH(:,1).*exp(-t.*t/2);
*Al@|5 for k=2:N;
Ob$``31{s HH(:,k)=exp(-t.*t/2).*HH(:,k)/sqrt(2.^(k-1)*...
Nfa&r factorial(k-1)*sqrt(variance));
25SWIpgG end
=[( 34 # if mod(N,2)==1;
~5KcbGD~ W=0:N-1; k=exp(-i*alpha*W); D=diag(k);
o "VKAP else
n~^SwOt~;5 W=0:N-2; W=cat(2,W,[N]); k=exp(-i*alpha*W); D=diag(k);
& A0OYV3i. end
=CLPz8 FF=Ts*HH*D*HH'*2;
2R/|/>T v % Reference:
%f]#P8V P % by 平先军.一种新的分数阶傅立叶变换快速算法.电子学报.
QOWGQl%! % 2001(3),Vol.29:406-408.
