How to creat a pairwise comparison matrix using a for loop ?

i have this matrix:

A=[2 3

4 7

5 4

2 1];

I need to get the following comparasion matrix

B=[

2-4 3-7

2-5 3-4

2-2 3-1

4-5 7-4

4-2 7-1

5-2 4-1]

B=

-2 -4

-3 -1

0 2

-1 3

2 6

3 3

Answer 1

[Jan]

A=[2    3; ...
   4    7; ...
   5    4; ...
   2    1];
idx = nchoosek(1:size(A, 1), 2);
B   = A(idx(:, 1), :) - A(idx(:, 2), :)

B = 6×2

-2 -4 -3 -1 0 2 -1 3 2 6 3 3

[Alejandrina Segura Delgado]

Thank you for answering my question.