How i can add all elements inside a matrix?

For example i have matrix 3X3 [-10 10 20 ; -20 20 10 ; -10 20 20 ] First want to add row1 elements,then row2, then row3,after getting row1,row2,row3 values,then want to add all the values of row1+row2+row3 to get a single value.Plese any help

Answer 1

[Torsten]

S_rows = sum(A,2);
S_complete = sum(S_rows);

Best wishes

Torsten.