How to create a matrix with the data of a comparison, upper triangular the percentage of similarity and lower triangular the times that were compared?

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German Preciat Gonzalez
评论： German Preciat Gonzalez 2016-6-29
I have a matrix with N rows and 4 columns. Each row represent a comparison of a file between different sources, columns represent the sources, each of the elements of the matrix can take values form 1-4 or NaN.
Column 1 have values of 1 or NaN
Column 2 have values of 1,2 or NaN
Column 3 have values of 1,2,3 or NaN
Column 4 have values of 1,2,3,4 or NaN
An example is:
M = [1 NaN 3 3;
1 2 NaN 2;
NaN 2 2 4;
1 2 1 1;
1 1 3 1;
1 1 3 4]
For example in row 1
[1 NaN 3 3]
sources 3 and 4 are similar, in source 2 there is not data, and source 1 is no similar to any other.
If I compare of M, source 1 with source 2 it was compared 4 times (because of NaN in M(1,2) and M(3,1)) and the similarity is 50% (2/4)
I would like to have a square matrix (4x4) with this data where the upper triangular matrix is the percentage of similarity and the lower triangular matrix the times that were compared, like this:
0 50* 25 40
4* 0 25 40
4 4 0 40
5 5 5 0
The stars are for the example when I compared source 1 with source 2 (indexes (1,2) and (2,1)).
I did that using a lot of IF and the script looks so ugly haha, "If" you can recomend me something I would really appreciate it

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采纳的回答

Andrei Bobrov
Andrei Bobrov 2016-6-29
a = permute(M,[3,2,1]);
b = permute(M,[2,3,1]);
x = sum(bsxfun(@eq,a,b),3);
y = sum(~isnan(bsxfun(@plus,a,b)),3);
out = tril(y,-1) + triu(x./y'*100,1);

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