How is this code getting executed?

for i=1 : u 
    x(:,i) = y(:,ij(i-1))-y(:ij(i-2)) 
end

[David Hill]

What is your specific question? I have no idea what you are trying to do.

[Varun Rahul Lale]

So I have a matrix Y which is 10*7 and an ij array which is something like this :

ij = [1 2;

2 1;

3 4;

4 3;

5 6;

6 5;

7 8;

8 7;

9 10;

10 9;

9 11;

11 9;

10 11;

11 10];

I have to execute yij = yi -yj. I found the above loop in one of the papers that I was referring to. In the end, I have to find the rank of a matrix.

[DGM]

It's unclear what operations you're trying to do. Y is 10x7 and ij is 14x2. You want the result of yi-yj, neither of which are defined. Is this supposed to mean Y*ij(:,1) - Y*ij(:,2)? If so, the array size mismatch means that this won't work either as a matrix multiplication or as an elementwise multiplication. How does the loop example correspond to the problem statement?

[Walter Roberson]

for i=1 : u 
  x(:,i) = y(:,ij(i-1))-y(:,ij(i-2)) 
end

You were missing a comma