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。
(jQ]<q%P `bXP
)$ function FF=frft_PXJ(N,alpha);
@C\>P49 %matrix
a3i;r M2 % FF is the kernel matrix of fractional Fourier transform
TF0DQP % \copyright: zjliu
"XvM1G&s` % Author's email:
zjliu2001@163.com wO\,?SI4 Ts=sqrt(2*pi/N); t=-(N-1)/2:(N-1)/2; t=t'; t=t*Ts;
wXj!bh8\r variance=N/2/pi; HH=zeros(N); HH(:,1)=1; HH(:,2)=2*t;
{/Mz/|% for k=3:N;
J2tD).G HH(:,k)=HH(:,k-1).*t*2-2*(k-2)*HH(:,k-2);
D)0pm?*5A end
:i{$p00
G HH(:,1)=1/sqrt(sqrt(variance))*HH(:,1).*exp(-t.*t/2);
mn5mdrv3WZ for k=2:N;
&RSUB;ymL HH(:,k)=exp(-t.*t/2).*HH(:,k)/sqrt(2.^(k-1)*...
Kterp%J? factorial(k-1)*sqrt(variance));
RDFOUqS end
W
PDL$y if mod(N,2)==1;
Z{'.fq2A W=0:N-1; k=exp(-i*alpha*W); D=diag(k);
1w30Vj2< else
.nGYx W=0:N-2; W=cat(2,W,[N]); k=exp(-i*alpha*W); D=diag(k);
c UJUZ@ol end
Y$tgz) FF=Ts*HH*D*HH'*2;
{'(1c)q> % Reference:
A4C4xts]N % by 平先军.一种新的分数阶傅立叶变换快速算法.电子学报.
h ~\bJ*Zp % 2001(3),Vol.29:406-408.