>> A = [1 2 3;
        4 5 6];

>> B = repelem(A, 2, 3)

B =

     1     1     1     2     2     2     3     3     3
     1     1     1     2     2     2     3     3     3
     4     4     4     5     5     5     6     6     6
     4     4     4     5     5     5     6     6     6