fcnunique.m

function [c,indA,indC,n] = fcnunique(a,rows) 
%UNIQUE Set unique.
%   C = UNIQUE(A) for the array A returns the same values as in A but with 
%   no repetitions. C will be sorted.    
%  
%   C = UNIQUE(A,'rows') for the matrix A returns the unique rows of A.
%   The rows of the matrix C will be in sorted order.
%  
%   [C,IA,IC] = UNIQUE(A) also returns index vectors IA and IC such that
%   C = A(IA) and A = C(IC).  
%  
%   [C,IA,IC] = UNIQUE(A,'rows') also returns index vectors IA and IC such
%   that C = A(IA,:) and A = C(IC,:). 
%  
%   [C,IA,IC] = UNIQUE(A,OCCURRENCE) and
%   [C,IA,IC] = UNIQUE(A,'rows',OCCURRENCE) specify which index is returned
%   in IA in the case of repeated values (or rows) in A. The default value
%   is OCCURENCE = 'first', which returns the index of the first occurrence 
%   of each repeated value (or row) in A, while OCCURRENCE = 'last' returns
%   the index of the last occurrence of each repeated value (or row) in A.
%  
%   [C,IA,IC] = UNIQUE(A,'stable') returns the values of C in the same order
%   that they appear in A, while [C,IA,IC] = UNIQUE(A,'sorted') returns the
%   values of C in sorted order. If A is a row vector, then C will be a row
%   vector as well, otherwise C will be a column vector. IA and IC are
%   column vectors. If there are repeated values in A, then IA returns the
%   index of the first occurrence of each repeated value.
% 
%   [C,IA,IC] = UNIQUE(A,'rows','stable') returns the rows of C in the same
%   order that they appear in A, while [C,IA,IC] = UNIQUE(A,'rows','sorted')
%   returns the rows of C in sorted order.
% 
%   The behavior of UNIQUE has changed.  This includes:
%     -	occurrence of indices in IA and IC switched from last to first
%     -	IA and IC will always be column index vectors
% 
%   If this change in behavior has adversely affected your code, you may 
%   preserve the previous behavior with:
% 
%        [C,IA,IC] = UNIQUE(A,'legacy')
%        [C,IA,IC] = UNIQUE(A,'rows','legacy') 
%        [C,IA,IC] = UNIQUE(A,OCCURRENCE,'legacy')
%        [C,IA,IC] = UNIQUE(A,'rows',OCCURRENCE,'legacy')
%
%   Examples:
%
%       a = [9 9 9 9 9 9 8 8 8 8 7 7 7 6 6 6 5 5 4 2 1]
%
%       [c1,ia1,ic1] = unique(a)
%       % returns
%       c1 = [1 2 4 5 6 7 8 9]
%       ia1 = [21 20 19 18 16 13 10 6]
%       ic1 = [8 8 8 8 8 8 7 7 7 7 6 6 6 5 5 5 4 4 3 2 1]
%
%       [c2,ia2,ic2] = unique(a,'stable')
%       % returns
%       c2 = [9 8 7 6 5 4 2 1]
%       ia2 = [1 7 11 14 17 19 20 21]'
%       ic2 = [1 1 1 1 1 1 2 2 2 2 3 3 3 4 4 4 5 5 6 7 8]'
%
%       c = unique([1 NaN NaN 2])
%       % NaNs compare as not equal, so this returns
%       c = [1 2 NaN NaN]
%
%   Class support for input A:
%      - logical, char, all numeric classes
%      - cell arrays of strings
%      -- 'rows' option is not supported for cell arrays
%      - objects with methods SORT (SORTROWS for the 'rows' option) and NE
%      -- including heterogeneous arrays
%
%   See also UNION, INTERSECT, SETDIFF, SETXOR, ISMEMBER, SORT, SORTROWS.

%   Copyright 1984-2012 The MathWorks, Inc.
%   $Revision: 1.24.4.13 $  $Date: 2012/07/28 23:09:26 $


if numel(a)==0
    c=[]; indA=[]; indC=[]; n=[];
    return
end

if nargin==2
    a = a(:,1)*-1312.76453255877 + a(:,2)*502.732375551395 + a(:,3)*226.888285443346;
end

if nargout==1
    sortA = sort(a);% Sort A and get the indices if needed.
    %groupsSortA = [true; diff(sortA)~=0];
    groupsSortA = sortA~=circshift(sortA,1);  groupsSortA(1)=true;        %FASTER!!  :)
else
    [sortA,indSortA] = sort(a);% Sort A and get the indices if needed.
    %groupsSortA = [true; diff(sortA)~=0];          % % groupsSortA indicates the location of non-matching entries. First element is always a member of unique list.
    groupsSortA = sortA~=circshift(sortA,1);  groupsSortA(1)=true;        %FASTER!!  :)
    
    indA = indSortA(groupsSortA);   % Find the indices of the sorted logical.
    if nargout>2
        indC = cumsum(groupsSortA);                         % Lists position, starting at 1.
        indC(indSortA) = indC;                              % Re-reference indC to indexing of sortA.
        if nargout>3
            n = diff([find(groupsSortA); numel(a)+1]); %number of occurences!
        end
    end
end
c = sortA(groupsSortA);   % Create unique list by indexing into sorted list.