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。
G_S2Q @|Q HpIWH* function FF=frft_PXJ(N,alpha);
(O"-6`w[ %matrix
/wU4^8Hz % FF is the kernel matrix of fractional Fourier transform
'+v[z=.8] % \copyright: zjliu
B3&C=*y % Author's email:
zjliu2001@163.com b=XXp`h~a Ts=sqrt(2*pi/N); t=-(N-1)/2:(N-1)/2; t=t'; t=t*Ts;
dO4Jf9) variance=N/2/pi; HH=zeros(N); HH(:,1)=1; HH(:,2)=2*t;
C_;A~iI7 for k=3:N;
47!k!cHa HH(:,k)=HH(:,k-1).*t*2-2*(k-2)*HH(:,k-2);
Ru@ { b` end
" 2Q*- HH(:,1)=1/sqrt(sqrt(variance))*HH(:,1).*exp(-t.*t/2);
W~j>&PK,? for k=2:N;
0DX)%s,KO HH(:,k)=exp(-t.*t/2).*HH(:,k)/sqrt(2.^(k-1)*...
@t2S"s$m factorial(k-1)*sqrt(variance));
n;e.N:p end
RC!9@H5S# if mod(N,2)==1;
|p`}vRv
Uh W=0:N-1; k=exp(-i*alpha*W); D=diag(k);
y'C else
Ou{VDE W=0:N-2; W=cat(2,W,[N]); k=exp(-i*alpha*W); D=diag(k);
=0mn6b9-= end
o^W.53yX FF=Ts*HH*D*HH'*2;
FD/=uIXH2 % Reference:
R5=M{ % by 平先军.一种新的分数阶傅立叶变换快速算法.电子学报.
5M\bH'1 % 2001(3),Vol.29:406-408.