MATLAB: Return all unique rows with unique elements

unique elements

How would I find all rows of a matrix which contain only unique elements? For example, if I have a matrix containing all 3-way combinations of the numbers 1-3:
>> x = allcomb(1:3, 1:3, 1:3)
x =
     1     1     1
     1     1     2
     1     1     3
     1     2     1
     1     2     2
     1     2     3
     1     3     1
     1     3     2
     1     3     3
     2     1     1
     2     1     2
     2     1     3
     2     2     1
     2     2     2
     2     2     3
     2     3     1
     2     3     2
     2     3     3
     3     1     1
     3     1     2
     3     1     3
     3     2     1
     3     2     2
     3     2     3
     3     3     1
     3     3     2
     3     3     3
I could do the following:
   y = unique(sort(x, 2), 'rows');    
   y(y(:,1) == y(:,2) | y(:,1) == y(:,3) | y(:,2) == y(:,3), :) = [];
But is there a more efficient way to accomplish this for matrices with an arbitrary number of columns?
Thanks, Dan

Best Answer

@andrei:
This does not work because it returns several rows which contain the same element. What I am looking for is a matrix of rows which only contain unique elements. In the above example, this is a single row [1 2 3], but in principle could be much larger. As an example, consider the following:
x = allcomb(1:5, 1:5, 1:5); 
y = unique(sort(x, 2), 'rows');    
y(y(:,1) == y(:,2) | y(:,1) == y(:,3) | y(:,2) == y(:,3), :) = []
Thanks, Dan
[I accidentally hit the accept this answer button. Please disregard.]
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