**Info**

This question is closed. Reopen it to edit or answer.

# How to operate on different rows of the same matrix?

1 view (last 30 days)

Show older comments

Good morning folks, I need your help to figure out a possible solution for my issue. I can't find a way out.

Let's consider this matrix A:

1 4 -2 0

2 0 -2 0

3 0 -3 0

4 2 -2 0

I want to operate on the rows, in order to do some operations. Let's stick, for easiness' sake, to this problem: I want to pair the first elements of two different rows. I.e.:

[1, 2]; [1, 3]; [1, 4]; [2, 3]; [2, 4]; [3, 4]

so, it's the first row with the second, the first with the third, the first with the fourth, the second with the third, the second with the fourth, so on...

I had the job done with nested for cycles, but... my supervisor wants me to use a different solution. I need help as I can't find a way out but I desperately need this!

##### 8 Comments

Rik
on 28 Oct 2020

### Answers (1)

Sudhakar Shinde
on 28 Oct 2020

Try this:

[A(1,1) A(2,1)] %[1 2]

[A(1,1) A(3,1)] %[1 3]

[A(1,1) A(4,1)] %[1 4]

[A(2,1) A(3,1)] %[2 3]

[A(2,1) A(4,1)] %[2 4]

[A(3,1) A(4,1)] %[3 4]

##### 5 Comments

Rik
on 28 Oct 2020

Or you don't use a nested loop with a dynamically exanding variable:

B=nchoosek(1:size(A,1),2);

B=mat2cell(B,ones(size(B,1),1),2);

### See Also

### Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!