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Calculate the remaining index of my data

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If i have
x= 1 2
3 4
2 5
1 5
is the index of my data. i want to get on remaining of these index but not need index that have i=j i.e [ (1 1) (2 2) (3 3)(4 4)(5 5) and not need fliplr of x i.e [(2 1)(4 3)(5 2)(5 1)]. so i want to the result
result=
1 3
1 4
2 3
2 4
3 5
4 5
that should not contain fliplr of any index.
  1 Comment
Rik
Rik on 27 Sep 2017
It is not clear what your question is. It sounds like you could solve your problem with logical indexing, or even find (and maybe a call to ismember(fliplr(A),A)), but without understanding your problem better I can't help you with actual code.

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Accepted Answer

the cyclist
the cyclist on 27 Sep 2017
Here is one way.
x= [1 2
3 4
2 5
1 5];
result = zeros(5*2,2);
ri = 1;
for ii=1:5
for jj = ii+1:5
result(ri,:) = [ii jj];
ri = ri+1;
end
end
isRowToRemove = ismember(result,x,'rows');
result(isRowToRemove,:) = [];
There is certainly a better way to pre-populate the array result with all possible row values than using the loops, but I got lazy.

More Answers (1)

OCDER
OCDER on 27 Sep 2017
%Getting index of an arbitrary matrix
[x, y] = find(ones(5, 'logical'));
x = [x y];
%Remove index i == j
x(x(:,1) == x(:,2), :) = [];
%Get unique x,y and not those that are y,x
x = unique(sort(x, 2), 'rows');
x =
1 2
1 3
1 4
1 5
2 3
2 4
2 5
3 4
3 5
4 5

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