how to assign the equality relationship for the elements symmetry to the diagnoal of a matrix

Hi, I have a 4 by 4 matrix which is

x0=[xo(1),xo(2),xo(3),xo(4)
    xo(5),xo(6),xo(7),xo(8)
    x0(9),xo(10),xo(11),xo(12)
    xo(13),xo(14),xo(15),xo(16)]

And I am trying to assign a relationship between elements in this matrix that elements which are symmetry to the diagonal are equal, to be specific, ( i ignored xo),

2=5, 3=9, 4=13, 7=10, 8=14, 12=15. Is is possible to use a for loop to assign this relationship?

Answer 1

[Bruno Luong]

% random test matrix
A = rand(4)

% symmetrize of A by copying the lower part to upper part
B = tril(A)+tril(A,-1).'

for i=1:0 % because you require a for-loop
end