matlab中的自相關

Question

我想問一下如何在聲波中的每一幀做自動相關函數，我的手並沒有內置函數，我做了一個代碼，我不知道它是對還是錯請幫助 也是我想要得到的基音週期

[sound, Fs]= wavread('aa.wav'); 

subplot(5,1,1);plot (sound);title('The Orignal Wave') 
frameSize= 10/10^3; 
overlapSize= 5/10^3; 

frameSize_samples = round(Fs*frameSize); 
overlapSize_samples= round(overlapSize* Fs); 

shift = frameSize_samples-overlapSize_samples; 

nframes=ceil((length(sound)-frameSize_samples)/shift); 

frames = zeros(nframes, frameSize_samples); 
for i=1:nframes 
     frames(i,:) = sound(((i-1)*shift+ 1):((i-1)*shift+ frameSize_samples))'; 
end 

subplot(5,1,2);plot (frames(:));title(' Wave after framing') 


w = rectwin(frameSize_samples)'; 

frames1 = zeros(nframes, frameSize_samples); 

for i=1:nframes 
    frames1(i,:)=(frames(i,:).*w); 
end 

%///////////////////////////////////////////////////////// 

% calc energy 
numSamples = length(sound); 
energy = zeros(1,nframes); 
for frame = 1:nframes 
    energy(frame) = sum(frames1(frame).^2);    %# Calculate frame energy 
end 
subplot(5,1,3);plot (energy(:));title(' Energy') 


% calc autocorrelation 


autocorrelation = zeros(1,nframes); 
for i=1:nframes 
    for k = 0:frameSize_samples 
     autocorrelation(i,:)= sum(frames(i)*frames(i+k)); 
    end 
end 


subplot(5,1,4);plot (autocorrelation(:));title(' autocorrelation') 

Answer 1

基於方程here。自相關方程看起來很好。但我很困惑frames。您將其定義爲2-D矩陣，但會將其線性編入索引（frames(i)）。

另外，for循環for k=0:frameSize_samples沒有做任何事;您將在每次迭代中分配相同的變量autocorrelation(i, :)，因此它將被覆蓋。