unique2

 UNIQUE 
 
  y = unique(x [,opt])
  [y,i,j] = unique(...)

 DIM    dimension
    1 MEAN of columns
    2 MEAN of rows
     N MEAN of  N-th dimension 
    default or []: first DIMENSION, with more than 1 element

 opt    options 
    'rows' 

 features:
 - can deal with NaN's (missing values)
 - compatible to Matlab and Octave

 see also: SUMSKIPNAN