UNIQUEWITHEQUALNANS

Set unique, treating NaNs as equal (v2.0, mar 2009)

Description

 UNIQUEWITHEQUALNANS - Set unique, treating NaNs as equal
    B = UNIQUEWITHEQUALNANS(A) for the array A returns the same values as in A
    but with no repetitions. B will also be sorted (NaNs as last).
 
    UNIQUEWITHEQUALNANS(A,'rows') for the matrix A returns the unique rows
    of A, treating NaNs as equal.
 
    [B,I,J] = UNIQUEWITHEQUALNANS(...) also returns index vectors I and J such
    that B = A(I) and A = B(J) (or B = A(I,:) and A = B(J,:)).
 
    [B,I,J] = UNIQUEWITHEQUALNANS(...,'first') returns the vector I to
    index the first occurrence of each unique value in A.
    UNIQUEWITHEQUALNANS(...,'last'), the default, returns the vector I to
    index the last occurrence.
 
    Example:
      A = [1 2 NaN ; 1 2 NaN ; 1 2 NaN] ;
      unique(A,'rows')
      % -> [1 2 NaN ; 1 2 NaN ; 1 2 NaN] ;
      uniquewithequalnans(A,'rows')
      %-> [1 2 NaN]
 
    For a cell array of strings, this function behaves exactly like UNIQUE.
 
    See also unique, ISEQUALWITHNANS.

v2.0, mar 2009 - update to deal with recent versions of UNIQUE

• MATLAB release: MATLAB 6.5 (R13)

[Hoi Wong]

Great tool. But you cannot just pass [] into unique as second argument. I modified it for my own use, but I'd encourage the original author to update it instead of having me posting a minor modification of your work. :)

[Jos]

@Hoi Wong: apparently TMW changed the internals of UNIQUE, so it is no longer backward compatible. I will update this function shortly.