replace a row of a matrix

[Trung BUI]

Hello users,

For examples, I have a matrix A = J(4,4,0) and other matrices: A1=(1, 4, 2, 1) , A2 = (3, 4, 2, 3). How could I replace the first row of matrix A with matrix A1, second row of matrix A with matrix A2, ...?

Thanks a lot in advance.

[Nick Cox]

. mat A1 = (1, 4, 2, 1) 

. mat A2 = (3, 4, 2, 3)

. mat A = A1 \ A2 

. mat li A 

A[2,4]
    c1  c2  c3  c4
r1   1   4   2   1
r1   3   4   2   3

and so on.

[Christophe Kolodziejczyk]

You can also use subscripts (Matrix A has 4 rows).

mat A[1,1]  =A1
mat A2[2,1] = A2

If you're planning to do something more complicated with matrices I suggest you use Mata.

[Trung BUI]

Thank you very much. Your codes are amazing.