我是Matlab的新手，正在尝试摆脱Java / C ++习惯。
问题是“我如何摆脱这些循环。”
我试图使用nchoosek（n0,2）摆脱其中一个循环，但又出现了另一个问题。（nchoosek的性能）
for j=2:n0 for i=1:j-1 %wij is the number of rows of A that have 1 at both column i and column j %summing col i and j to find #of common 1's wij = length(find((A(:,i)+A(:,j))==2)); %store it W(1,j)=wij; %testing whether the intersection of any two columns is too large if wij>= (1+epsilon)*u2; %create and edge between col ij end end end
回答：
我假设A是只有0和1的数组。
然后，您可以通过写入来创建一个nCol-by-nCol数组B，其中各列之间有“距离”
B = A'*A; %'# B(i,j) = length(find((A(:,i)+A(:,j))==2)) %# threshold largeIntersection = B >= u2; %# find i,j of large intersections [largeIJ(:,1),largeIJ(:,2)] = find(largeIntersection); %# make sure we only get unique i,j pairs largeIJ = unique(sort(largeIJ,2),'rows');
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