'It didn't work' is not a particularly helpful comment, rather you need to tell us what error you got, and why you think it didn't work:
sort is indeed the function you need, in particular the 2nd return value. You just then need to reorder the indices of the matrix according to that second value:
m = [0.6 0.27 0.03 0.5];
[~, order] = sort(m);
rank(order) = 1:numel(m)
Note that you don't have arrays in a matrix, but number. An array is the same as a matrix.
