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Corrected separately complex number counting.

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Aleksejs Mirnijs
2019-12-25 11:08:18 +02:00
parent 790c73cab6
commit e04020511a
1 changed files with 17 additions and 9 deletions
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matlab/myfft4_real_imag.m
+17 -9
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@@ -5,7 +5,7 @@
clear; % clears all previus values from memory
clc; % clear command window
fs = 44100; % samplinf freq.
fftLength=512; % windowlength
fftLength=128; % windowlength
stage_num = log2(fftLength);
% signal frequencies
max = 2048 - 1 ;
@@ -90,8 +90,11 @@ real_n = zeros(bits+1,fftLength);
imag_n = zeros(bits+1,fftLength);
Wn = zeros(1,fftLength/2); % complex
Wr = zeros(1,fftLength/2); % real
Wi = zeros(1,fftLength/2); % imag
%Wr = zeros(1,fftLength/2); % real
%Wi = zeros(1,fftLength/2); % imag
%
% Wr_sfi = zeros(1,fftLength/2);
% Wi_sfi = zeros(1,fftLength/2);
%% New stages
@@ -104,24 +107,29 @@ for st = 0 : stage_num;
else st > 0;
for n = 1 : fftLength/2;
Wn(n) = exp(-j * (n-1) * 2 * pi/ 2^(st) );
Wr(n) = real(Wn(n));
Wi(n) = imag(Wn(n));
Wr(n) = real(Wn(n));%sfi(real(Wn(n)),16,15);%
Wi(n) = imag(Wn(n));%sfi(imag(Wn(n)),16,15);%
end
for i = 1 : 2^st : fftLength;
for k = 0 : 2^(st-1)-1;
% Even
stage(st+1,i+k) = stage(st,i+k) + Wn(k+1)*stage(st,i+k+2^(st-1));
real_n(st+1,i+k) = real_n(st,i+k) + Wn(k+1)*real_n(st,i+k+2^(st-1));
imag_n(st+1,i+k) = imag_n(st,i+k) + Wn(k+1)*imag_n(st,i+k+2^(st-1));
real_n(st+1,i+k) = real_n(st,i+k) + Wr(k+1)*real_n(st,i+k+2^(st-1)) - Wi(k+1)*imag_n(st,i+k+2^(st-1));
imag_n(st+1,i+k) = imag_n(st,i+k) + Wi(k+1)*real_n(st,i+k+2^(st-1)) + + Wr(k+1)*imag_n(st,i+k+2^(st-1));
% Odd
stage(st+1,i+k+2^(st-1)) = stage(st,i+k) - Wn(k+1)*stage(st,i+k+2^(st-1));
real_n(st+1,i+k+2^(st-1)) = real_n(st,i+k) - Wn(k+1)*real_n(st,i+k+2^(st-1));
imag_n(st+1,i+k+2^(st-1)) = imag_n(st,i+k) - Wn(k+1)*imag_n(st,i+k+2^(st-1));
real_n(st+1,i+k+2^(st-1)) = real_n(st,i+k) - Wr(k+1)*real_n(st,i+k+2^(st-1)) + Wi(k+1)*imag_n(st,i+k+2^(st-1));
imag_n(st+1,i+k+2^(st-1)) = imag_n(st,i+k) - Wi(k+1)*real_n(st,i+k+2^(st-1)) - Wr(k+1)*imag_n(st,i+k+2^(st-1));
end
end
end
end
% for n = 1 : fftLength/2;
% Wr_sfi(n) = sfi(real(Wn(n)),16,15);
% Wi_sfi(n) = sfi(imag(Wn(n)),16,15);
% end
%% Ploting out
% slowly plot result
figure(5)