MATLAB: Find a subset of unique permutations

permsunique

I have many arrays A of varying length. For any given A, I'd like to find all the unique sets of three elements of A. For example, if A has five elements:
A = [5 6 2 4 7];
one combination of three elements in A is [5 6 2], another combination is [5 6 4], and so on. When I work this out manually I get these combinations:
5 6 2   
5 6   4   
5 6     7
5   2 4  
5   2   7
5     4 7
  6 2 4  
  6 2   7
  6   4 7
    2 4 7
The appearance of the solutions above makes me think there may be a clever way to use an identity matrix, but I can't quite think of how. Or perhaps there's a way to use perms, perhaps with sort and unique?
Can you think of a way to get all 3-element subsets of an array?

Best Answer

Why not use NCHOOSEK?
A = [5 6 2 4 7]; 
nchoosek(A,3)
ans =
       5     6     2
       5     6     4
       5     6     7
       5     2     4
       5     2     7
       5     4     7
       6     2     4
       6     2     7
       6     4     7
       2     4     7
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