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。
}N3V5cab %*lp< D function FF=frft_PXJ(N,alpha);
6*IpAIh %matrix
KP3n^
$~ % FF is the kernel matrix of fractional Fourier transform
6*u,c^a % \copyright: zjliu
9)+@0fG) % Author's email:
zjliu2001@163.com ?^ZXU0IkP Ts=sqrt(2*pi/N); t=-(N-1)/2:(N-1)/2; t=t'; t=t*Ts;
BQ#3QL't variance=N/2/pi; HH=zeros(N); HH(:,1)=1; HH(:,2)=2*t;
rH&G<o&, for k=3:N;
V!4a*,Pz HH(:,k)=HH(:,k-1).*t*2-2*(k-2)*HH(:,k-2);
#~^btL'dHF end
o(*F])d; HH(:,1)=1/sqrt(sqrt(variance))*HH(:,1).*exp(-t.*t/2);
'-vE%U@< for k=2:N;
o0ZIsrr
HH(:,k)=exp(-t.*t/2).*HH(:,k)/sqrt(2.^(k-1)*...
c<wavvfUo factorial(k-1)*sqrt(variance));
%}q.cV end
%KtU1A([" if mod(N,2)==1;
B0d%c&N${ W=0:N-1; k=exp(-i*alpha*W); D=diag(k);
m9$ a"$c else
B^fT>1P W=0:N-2; W=cat(2,W,[N]); k=exp(-i*alpha*W); D=diag(k);
O:Va&Cyj* end
q-nER< FF=Ts*HH*D*HH'*2;
o#>a 5 % Reference:
KOey8tB)1 % by 平先军.一种新的分数阶傅立叶变换快速算法.电子学报.
2j&v;dmh< % 2001(3),Vol.29:406-408.