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。
6J%SkuxR EXa6"D function FF=frft_PXJ(N,alpha);
L 8bq3Q'p %matrix
wk9tJ#} % FF is the kernel matrix of fractional Fourier transform
?N11R? 8 % \copyright: zjliu
JB%6G|Z % Author's email:
zjliu2001@163.com `9K'I-hv<8 Ts=sqrt(2*pi/N); t=-(N-1)/2:(N-1)/2; t=t'; t=t*Ts;
Om}&`AP}; variance=N/2/pi; HH=zeros(N); HH(:,1)=1; HH(:,2)=2*t;
Tj:+:B(HB for k=3:N;
~d{E> J77j HH(:,k)=HH(:,k-1).*t*2-2*(k-2)*HH(:,k-2);
b17p; wS end
#Q'i/|g HH(:,1)=1/sqrt(sqrt(variance))*HH(:,1).*exp(-t.*t/2);
}=f}@JlFB for k=2:N;
JH)&Ca >S HH(:,k)=exp(-t.*t/2).*HH(:,k)/sqrt(2.^(k-1)*...
E&& 80[tN] factorial(k-1)*sqrt(variance));
6_XX[.% end
U4N
S.`V if mod(N,2)==1;
N_gjOE`x5 W=0:N-1; k=exp(-i*alpha*W); D=diag(k);
-\NB*|9m| else
{ @-Q1 W=0:N-2; W=cat(2,W,[N]); k=exp(-i*alpha*W); D=diag(k);
(4g; -*N end
'rR\H 2b
FF=Ts*HH*D*HH'*2;
e#zGLxa % Reference:
#;mZ3[+i5 % by 平先军.一种新的分数阶傅立叶变换快速算法.电子学报.
W _DO8n X % 2001(3),Vol.29:406-408.
