A = [1.11 4.12 7.13 10.14
     2.21 5.22 8.23 11.24
     3.31 6.32 9.33 12.34]

[A(1),A(2),A(3),A(4),A(12)]

[A(1,1),A(2,1),A(3,1),A(1,2),A(3,4)]