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。
p2vUt iC+H; s5< function FF=frft_PXJ(N,alpha);
w&cyGd D5 %matrix
a&VJ YAB % FF is the kernel matrix of fractional Fourier transform
{-`OE % \copyright: zjliu
c] R![sa % Author's email:
zjliu2001@163.com Ru aJ9O Ts=sqrt(2*pi/N); t=-(N-1)/2:(N-1)/2; t=t'; t=t*Ts;
^JDV4>S\ variance=N/2/pi; HH=zeros(N); HH(:,1)=1; HH(:,2)=2*t;
!jq6cND for k=3:N;
H&IP>8Dk HH(:,k)=HH(:,k-1).*t*2-2*(k-2)*HH(:,k-2);
2^ M+s\p end
&LQab>{*K HH(:,1)=1/sqrt(sqrt(variance))*HH(:,1).*exp(-t.*t/2);
FN`kSTm*0! for k=2:N;
"FIx^ HH(:,k)=exp(-t.*t/2).*HH(:,k)/sqrt(2.^(k-1)*...
[eP]8G\
W factorial(k-1)*sqrt(variance));
2=M!lB
* end
V\hct$ 7Vm if mod(N,2)==1;
s? #lhI W=0:N-1; k=exp(-i*alpha*W); D=diag(k);
L^s;kkB else
+`3ZH9 W=0:N-2; W=cat(2,W,[N]); k=exp(-i*alpha*W); D=diag(k);
~(]DNXB8I` end
IE f^.Z FF=Ts*HH*D*HH'*2;
+r P<m % Reference:
G.e\#_RR? % by 平先军.一种新的分数阶傅立叶变换快速算法.电子学报.
deY<+! % 2001(3),Vol.29:406-408.
