Diagonal Elements of the Square Matrix
I am calculating Sorensen-Dice coefficient (2|A and B|/|A|+|B|) but diagonal elements (intersection with itself) of the square matrix is equal to zero. It is not a big problem but how can I convert them into ones. Thanks for the help.
v = [1 1 0 0 1 1 0; 1 1 0 1 0 0 0; 0 0 0 0 0 1 1]
d = squareform(pdist(v,@(a,b)(2 * sum((a.*b),2))./(sum(a) + sum(b,2))));
2 件の回答
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If the diagonal is already EXACTLY zero, then this will suffice:
M = M + eye(size(M));
If they are only approximately zero, then you could do this:
M(find(eye(size(M)))) = 1;
For example,
M = magic(5)
M =
17 24 1 8 15
23 5 7 14 16
4 6 13 20 22
10 12 19 21 3
11 18 25 2 9
M(find(eye(size(M)))) = 1;
M
M =
1 24 1 8 15
23 1 7 14 16
4 6 1 20 22
10 12 19 1 3
11 18 25 2 1
1 件のコメント
Thank you for your reply. It is working but I still didn't understand why I get zeros instead of ones.
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Another way:
M(1:size(M,1)+1:end) = 1;
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