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。
YXTd^M~@D ~H`(z zk function FF=frft_PXJ(N,alpha);
{i:Ayhq~& %matrix
k0-,qM#p;X % FF is the kernel matrix of fractional Fourier transform
F0+@FS0 % \copyright: zjliu
2(NN QU@Uz % Author's email:
zjliu2001@163.com )Jd{WC. Ts=sqrt(2*pi/N); t=-(N-1)/2:(N-1)/2; t=t'; t=t*Ts;
<,(Ww variance=N/2/pi; HH=zeros(N); HH(:,1)=1; HH(:,2)=2*t;
__,}/|K2 for k=3:N;
1EA} [x HH(:,k)=HH(:,k-1).*t*2-2*(k-2)*HH(:,k-2);
R>`TV(W`9 end
Z$ Mc{ HH(:,1)=1/sqrt(sqrt(variance))*HH(:,1).*exp(-t.*t/2);
O.wk*m!9 for k=2:N;
Dq~D4 | HH(:,k)=exp(-t.*t/2).*HH(:,k)/sqrt(2.^(k-1)*...
t+ O7dZt%r factorial(k-1)*sqrt(variance));
e{`DvfY21 end
T \$r| if mod(N,2)==1;
sBWLgJz?C W=0:N-1; k=exp(-i*alpha*W); D=diag(k);
9y5n G else
K7gqF~5x~ W=0:N-2; W=cat(2,W,[N]); k=exp(-i*alpha*W); D=diag(k);
uHpSE?y/ end
? Glkhf7( FF=Ts*HH*D*HH'*2;
&oqzQ+H % Reference:
>,QW74o % by 平先军.一种新的分数阶傅立叶变换快速算法.电子学报.
NW@guhK . % 2001(3),Vol.29:406-408.
