//A Marix
A = [ 10    5    2    56.1385
       2   10    5    61.8331
       5   10   17    46.2755
      10   17    5    70.5242
       5   17   30    66.5410
      30    5   17    86.5961]
      
b = [10 2]             
//Copy A to C
      
C=A

// interchange row 1 and row 2 of C
// you can interchange anything in C using A
// you kept the original matrix A unchanged.

C(1,:)=A(2,:)
C(2,:)=A(1,:)

// Setting row 1 and 2 to zero

C(1:2,:)=0

// Deleting row 1 and 2 of C

C(1:2,:)=[]

//adding a number in a row vector
//copy b to v
v=b
v=[v,5]

//another approach
//copy b to v
v=b
v(3,1)=5

v=b
v(1,3)=5  //If you know the location of element to be added