Switch signs to positive in the diagonal of a matrix

Hi

So I have an already existing 6x6 matrix, but I would like to make sure that the diagonals are all positive.

Thus, how do I transform/replace the diagonal of my matrix to be all positive?

I have tried to seach for, how to replace the diagonal with a vector, but without luck.

If I could replace the original diagonal with the absolute diagonal, this would also do it.

Answer 1

[David Hill]

m=randi(10,6)-5

m = 6×6

0 2 1 2 5 -3 1 -3 1 -1 5 -2 4 1 -4 2 4 -1 -3 2 1 -4 2 -2 3 5 3 1 5 4 3 5 5 -2 5 0

d=abs(diag(m));
M=m.*~eye(size(m))+diag(d)

M = 6×6

0 2 1 2 5 -3 1 3 1 -1 5 -2 4 1 4 2 4 -1 -3 2 1 4 2 -2 3 5 3 1 5 4 3 5 5 -2 5 0

[Jonas]

Thank you so much, David! Worked just the way I wanted to! :-)