Operations between every 2 different elements in a cell?

Hi all,

I have a cell like this:

K>> ur

ur =

    4×3 cell array

      {[1]}    {'-1 -1'}    {1×201 cell}
      {[2]}    {'1 -1' }    {1×201 cell}
      {[4]}    {'1  1' }    {1×201 cell}
      {[3]}    {'-1  1'}    {1×201 cell}

I'd like to perform some operations between every 2 elements of the 3rd column of ur, manually be like this:

operation(ur{1, 3}, ur{2, 3}) % 1 and 2
operation(ur(1, 3), ur(3, 3)) % 1 and 3
operation(ur(1, 3), ur(4, 3)) % 1 and 4
operation(ur(2, 3), ur(3, 3)) % 2 and 3
operation(ur(2, 3), ur(4, 3)) % 2 and 4
operation(ur(3, 3), ur(4, 3)) % 3 and 4

The number of cell rows is not limited to 4. Is there a way to do this in a loop? Or whatever automatic? I think I just need to pick the correct index to perform the operation, but how?

Many thanks!

Edit: the operations should all be curly brackets:

operation(ur{m, 3}, ur{n, 3}) % m and n

[Jan]

What is operation? Why do you use curly braces in the first line and round parentheses afterwards?

[Xiaohan Du]

My mistake, it should all be curly brackets. Operation here is a function in my code, this function takes ur{m, 3} and ur{n, 3} and gives a matrix as a result.

Answer 1

[Jan]

Maybe you mean:

index = nchoosek(1:4, 2);
for k = 1:size(index, 1)
  operation(ur{index(k, 1), 3}, ur{index(k, 1), 3});
end

[Xiaohan Du]

Thanks Jan!