Selecting unique pairs from a vector

26 views (last 30 days)
Afternoon all,
Suppose I have a vector
imax = [1;2;3;4;5;6];
I would like to find every set of pairs available in that matrix, so that
pairs = [1,2; 1,3; 1,4; 1,5; 1,6; 2,3; 2,4; 2,5; 2,6; 3,4; 3,5; 3,6; 4,5; 4,6; 5,6];
Where if we have the pair 1,2 we don't also have the pair 2,1. I have got this far, but it's obviously not working. Can anyone help me over the last little hurdle?
% Find every pairwise combination of indexes
[p,q] = meshgrid(imax, imax);
pairs = [p(:) q(:)];
pairs(pairs(:,1)==pairs(:,2),:) = [];
Many thanks

Accepted Answer

Azzi Abdelmalek
Azzi Abdelmalek on 9 Sep 2016
Edited: Azzi Abdelmalek on 9 Sep 2016
imax = [1;2;3;4;5;6]
out=nchoosek(imax,2)
  1 Comment
jlt199
jlt199 on 9 Sep 2016
That's a lot simpler than my answer:
[p,q] = meshgrid(imax, imax);
pairs = [p(:) q(:)];
pairs(pairs(:,1)>=pairs(:,2),:) = [];
Thank you very much

Sign in to comment.

More Answers (0)

Products

Community Treasure Hunt

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

Start Hunting!