How to vectorize this nested loop for optimized performance
显示 更早的评论
hello everybody, I have been trying to optimize this nested for loop which is very very slow, but with no success
for i=1:size(Sxx,2)-1
for j=1:size(Sxx,2)-1
A=Sxx(:,i).*conj(Sxx(:,j));
B= (ifft(A, 'symmetric'));
[~, T(i,j)] = max(B(1:round(end/2)));
end
end
any help is appreciated!
采纳的回答
My advice would be not to vectorize it completely (although there are ways to do so), but rather reduce it to one loop as below.
[m,n]=size(Sxx);
k=1:round(m/2);
SxxConj=conj(Sxx(:,1:n-1));
T=nan(n-1);
for i=1:n-1
B=ifft(Sxx(:,i).*SxxConj, [],1,'symmetric'); %If <R2016b use bsxfun
[~,T(i,:)]=max(B(k,:),[],1); %EDITED
end
You could also convert this to a parfor loop if the serial performance is insufficient.
1 个评论
Matt J
2017-12-19
Comment by Yodish:
Definitely faster (probably not enough yet though for my purposes) and more elegant, thanks Matt
PS. index of B needs to be swapped in second last line
更多回答（0 个）
类别
在 帮助中心 和 File Exchange 中查找有关 Loops and Conditional Statements 的更多信息
产品
Translated by 
