Sum a value in a matrix

Hi!

How could I sum a value in a row of a Matrix? Imagine I have:

(0,0,0;0,0,0;0,0,0;0,0,0) and I would like to have (0,0,0;3,3,3;0,0,0;0,0,0)

How could I get this result?

Thank you

Answer 1

[KSSV]

A = zeros(4,3) ; 
A(2,:) = 3 ;

Answer 2

[Ameer Hamza]

If you want to sum it to an arbitrary matrix row, then you can try the following methods

M = [1 2 3; 4 5 6; 7 8 9; 10 11; 12];
M_new = M + [0; 3; 0; 0];

This will add 3 to the second row of M. Similarly; you can also use the following equivalent statement

M_new = M;
M_new(2,:) = M_new(2,:)+3;