How to apply operations (add/subtract) to only a certain row range between 2 matrics?

Lets say I have 2 matrics with n rows:

A = 1 2 6 
    3 5 6 
    2 4 6 
    .
    .
    .
    3 3 1 

B = 1 5 6 
    2 5 7 
    8 5 3 
    .
    .
    .
    3 4 5

And I want to add Row 2 to Row (n) of both matrics up (skipping row 1)

I know for this the coding should be:

.

C = A(2:n,:) + B(2:n,:)
.

So the result be like:

C = - - -
    5 10 13
    10 9 9
    .
    .
    .
    6 7 6

and after that another matric is to add Row 1 and, Row 3 to Row (n), of both matrics (skipping row 2)

D = 2  7 12
    -  - -
    10 9 9
    .
    .
    .
    6 7 6
.

then Row 1 and, Row 2 and, Row 4 to Row (n), of both matrics (skipping row 3) .

E = 2  7  12
    5  10 13
    -  -  -
    .
    .
    .
    6  7  6

all the way to Row 1 to Row (n-1) of both matrics. (skipping last row)

[Adam]

Please give an example of your desired output as well as input! The description is confusing me!

[luc]

the function A(n,:) selects the nth row, the function A(:,m) the mth column.

If you want to add row 2 of A, to B row 4 just type:

B(4,:)=B(4,:)+A(2,:)

I hope this helps

[hithere]

Sorry about the confusion. I try to put up a clearer explaination

[Adam]

Is this not just the equivalent of:

C = ( n - 1 ) * A + ( n - 1 ) * B;

if you keep adding your results to the result of the previous calculation?

Every row of A will be added to the equivalent row of B (n-1) times, only being missed out of the maths once each. Or am I misunderstanding what you are aiming for?

[hithere]

Sorry Adam, it's not adding up. It should result in different matrics. Eg, C, D, E, F .... So sorry

Answer 1

[Sarah]

To add the rows of the matrices, use A(i,:)+B(j,:) where i and j represent your row number.

Happy Coding.

Sarah