Average matrix values across diagonal

Hi all :)

I have an asymmetric structural connectivity matrix size 376 by 376 where the elements Cij and Cji are different. What I am trying to do is to average the values contained in Cij and Cji so that I have a symmetric matrix. Sp basically I am trying to average values "across the diagonal" of my matrix.

Any help would be appreciated!

Thanks :)

Answer 1

[Asmit Singh]

Hey, I think this is what you require. This basically takes a mean over the diagonally opposite numbers, to create a symmetrical matrix.

% replace with the needed matrix
matrix = [1,2,3 ; 4,5,6 ; 7,8,9];
display(matrix)

% row/column size
siz = size(matrix);
n = siz(1);

for i= 1:n
    for j = i:n
        
        matrix(i,j) = (matrix(i,j)+matrix(j,i))/2;
        matrix(j,i) = matrix(i,j);

    end
end

display(matrix);

[Johanna Popp]

awesome, thank you so much!