pufeng_xihua_fushu.m

是信号处理方面欠采样的源程序 ,是很不错的程序,可以这方面的学者一些参考价值

function [f_fun,mag]=pufeng_ss(st_fs_fun,fs_fun,i)
N=length(st_fs_fun);
spectrum=abs(st_fs_fun);
%figure(11)
%plot((0:N-1)/N*fs_fun,spectrum)
%wz=i
if i==1
   wz=1; 
   mag=spectrum(i);
elseif i==N
   wz=N;
   mag=spectrum(i);
elseif spectrum(i+1)==spectrum(i-1)%2
   wz=i;
   mag=spectrum(i);
elseif spectrum(i+1)<spectrum(i-1)%3
   l=i;
   R=spectrum(l)/spectrum(l-1);
   delta_l=N/pi*atan(sin(pi/N)/(R+cos(pi/N)));
   mag=spectrum(i)/(sin(pi*delta_l)/sin(pi/N*delta_l))*N;
   wz=l-delta_l;
else
   l=i;
   R=spectrum(l)/spectrum(l+1);
   delta_l=N/pi*atan(sin(pi/N)/(R+cos(pi/N)));
   mag=spectrum(i)/(sin(pi*delta_l)/sin(pi/N*delta_l))*N;
   wz=l+delta_l;
end
f_fun=(wz-1)/N*fs_fun;