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2008-12-02 10:26 |
实现分数傅立叶变换的matlab程序
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。 ,u^{zYoW
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function FF=frft_PXJ(N,alpha); kaQ NcMcq
%matrix J5F @<vi
% FF is the kernel matrix of fractional Fourier transform 5@ r6'Z
% \copyright: zjliu C|Y[T{g?t
% Author's email: zjliu2001@163.com 7FPSBvU#/
Ts=sqrt(2*pi/N); t=-(N-1)/2:(N-1)/2; t=t'; t=t*Ts; /YUW)?o!^N
variance=N/2/pi; HH=zeros(N); HH(:,1)=1; HH(:,2)=2*t; Q W,:'\G
for k=3:N; 3u[8;1}7Q
HH(:,k)=HH(:,k-1).*t*2-2*(k-2)*HH(:,k-2); Jn d_cJ ]a
end $#+D :W)az
HH(:,1)=1/sqrt(sqrt(variance))*HH(:,1).*exp(-t.*t/2); W|Sab $h
for k=2:N; RCYv 2=m>Q
HH(:,k)=exp(-t.*t/2).*HH(:,k)/sqrt(2.^(k-1)*... HfhI9f_ x
factorial(k-1)*sqrt(variance)); Kr'? h 'F
end 9 Xl#$d5
if mod(N,2)==1; QICxSk
W=0:N-1; k=exp(-i*alpha*W); D=diag(k); :L+ xEL
else #9r}Kr =P
W=0:N-2; W=cat(2,W,[N]); k=exp(-i*alpha*W); D=diag(k); r5UV BV8T
end (B$>o.(JA
FF=Ts*HH*D*HH'*2; -6I*k |%8T
% Reference: T 30f p
% by 平先军.一种新的分数阶傅立叶变换快速算法.电子学报. lb}RPvQE
% 2001(3),Vol.29:406-408.
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