--- /dev/null
+## Copyright (C) 2000-2012 Paul Kienzle
+## Copyright (C) 2008-2009 Jaroslav Hajek
+##
+## This file is part of Octave.
+##
+## Octave is free software; you can redistribute it and/or modify it
+## under the terms of the GNU General Public License as published by
+## the Free Software Foundation; either version 3 of the License, or (at
+## your option) any later version.
+##
+## Octave is distributed in the hope that it will be useful, but
+## WITHOUT ANY WARRANTY; without even the implied warranty of
+## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+## General Public License for more details.
+##
+## You should have received a copy of the GNU General Public License
+## along with Octave; see the file COPYING. If not, see
+## <http://www.gnu.org/licenses/>.
+
+## -*- texinfo -*-
+## @deftypefn {Function File} {} unique (@var{x})
+## @deftypefnx {Function File} {} unique (@var{x}, "rows")
+## @deftypefnx {Function File} {} unique (@dots{}, "first")
+## @deftypefnx {Function File} {} unique (@dots{}, "last")
+## @deftypefnx {Function File} {[@var{y}, @var{i}, @var{j}] =} unique (@dots{})
+## Return the unique elements of @var{x}, sorted in ascending order.
+## If the input @var{x} is a vector then the output is also a vector with the
+## same orientation (row or column) as the input. For a matrix input the
+## output is always a column vector. @var{x} may also be a cell array of
+## strings.
+##
+## If the optional argument @code{"rows"} is supplied, return the unique
+## rows of @var{x}, sorted in ascending order.
+##
+## If requested, return index vectors @var{i} and @var{j} such that
+## @code{x(i)==y} and @code{y(j)==x}.
+##
+## Additionally, if @var{i} is a requested output then one of @code{"first"} or
+## @code{"last"} may be given as an input. If @code{"last"} is specified,
+## return the highest possible indices in @var{i}, otherwise, if @code{"first"}
+## is specified, return the lowest. The default is @code{"last"}.
+## @seealso{union, intersect, setdiff, setxor, ismember}
+## @end deftypefn
+
+function [y, i, j] = unique (x, varargin)
+
+ if (nargin < 1)
+ print_usage ();
+ endif
+
+ if (nargin > 1)
+ ## parse options
+ if (iscellstr (varargin))
+ varargin = unique (varargin);
+ optfirst = strmatch ("first", varargin, "exact") > 0;
+ optlast = strmatch ("last", varargin, "exact") > 0;
+ optrows = strmatch ("rows", varargin, "exact") > 0;
+ if (optfirst && optlast)
+ error ('unique: cannot specify both "last" and "first"');
+ elseif (optfirst + optlast + optrows != nargin-1)
+ error ("unique: invalid option");
+ endif
+ else
+ error ("unique: options must be strings");
+ endif
+
+ if (optrows && iscell (x))
+ warning ('unique: "rows" is ignored for cell arrays');
+ optrows = false;
+ endif
+ else
+ optfirst = false;
+ optrows = false;
+ endif
+
+ ## FIXME -- the operations
+ ##
+ ## match = (y(1:n-1) == y(2:n));
+ ## y(idx) = [];
+ ##
+ ## are very slow on sparse matrices. Until they are fixed to be as
+ ## fast as for full matrices, operate on the nonzero elements of the
+ ## sparse array as long as we are not operating on rows.
+
+ if (issparse (x) && ! optrows && nargout <= 1)
+ if (nnz (x) < numel (x))
+ y = unique ([0; (full (nonzeros (x)))], varargin{:});
+ else
+ ## Corner case where sparse matrix is actually full
+ y = unique (full (x), varargin{:});
+ endif
+ return;
+ endif
+
+ if (optrows)
+ n = rows (x);
+ dim = 1;
+ else
+ n = numel (x);
+ dim = (rows (x) == 1) + 1;
+ endif
+
+ y = x;
+ ## Special cases 0 and 1
+ if (n == 0)
+ if (! optrows && isempty (x) && any (size (x)))
+ if (iscell (y))
+ y = cell (0, 1);
+ else
+ y = zeros (0, 1, class (y));
+ endif
+ endif
+ i = j = [];
+ return;
+ elseif (n == 1)
+ i = j = 1;
+ return;
+ endif
+
+ if (optrows)
+ if (nargout > 1)
+ [y, i] = sortrows (y);
+ else
+ y = sortrows (y);
+ endif
+ match = all (y(1:n-1,:) == y(2:n,:), 2);
+ idx = find (match);
+ y(idx,:) = [];
+ else
+ if (! isvector (y))
+ y = y(:);
+ endif
+ if (nargout > 1)
+ [y, i] = sort (y);
+ else
+ y = sort (y);
+ endif
+ if (iscell (y))
+ match = strcmp (y(1:n-1), y(2:n));
+ else
+ match = (y(1:n-1) == y(2:n));
+ endif
+ idx = find (match);
+ y(idx) = [];
+ endif
+
+ if (isargout (3))
+ j = i;
+ if (dim == 1)
+ j(i) = cumsum ([1; !match]);
+ else
+ j(i) = cumsum ([1, !match]);
+ endif
+ endif
+
+ if (isargout (2))
+ if (optfirst)
+ i(idx+1) = [];
+ else
+ i(idx) = [];
+ endif
+ endif
+
+endfunction
+
+%!assert(unique([1 1 2; 1 2 1; 1 1 2]),[1;2])
+%!assert(unique([1 1 2; 1 0 1; 1 1 2],'rows'),[1 0 1; 1 1 2])
+%!assert(unique([]),[])
+%!assert(unique([1]),[1])
+%!assert(unique([1 2]),[1 2])
+%!assert(unique([1;2]),[1;2])
+%!assert(unique([1,NaN,Inf,NaN,Inf]),[1,Inf,NaN,NaN])
+%!assert(unique({'Foo','Bar','Foo'}),{'Bar','Foo'})
+%!assert(unique({'Foo','Bar','FooBar'}'),{'Bar','Foo','FooBar'}')
+%!assert(unique(zeros(1,0)), zeros(0,1))
+%!assert(unique(zeros(1,0), 'rows'), zeros(1,0))
+%!assert(unique(cell(1,0)), cell(0,1))
+%!assert(unique({}), {})
+%!assert(unique([1,2,2,3,2,4], 'rows'), [1,2,2,3,2,4])
+%!assert(unique([1,2,2,3,2,4]), [1,2,3,4])
+%!assert(unique([1,2,2,3,2,4]', 'rows'), [1,2,3,4]')
+%!assert(unique(sparse([2,0;2,0])), [0,2]')
+%!assert(unique(sparse([1,2;2,3])), [1,2,3]')
+%!assert(unique([1,2,2,3,2,4]', 'rows'), [1,2,3,4]')
+%!assert(unique(single([1,2,2,3,2,4]), 'rows'), single([1,2,2,3,2,4]))
+%!assert(unique(single([1,2,2,3,2,4])), single([1,2,3,4]))
+%!assert(unique(single([1,2,2,3,2,4]'), 'rows'), single([1,2,3,4]'))
+%!assert(unique(uint8([1,2,2,3,2,4]), 'rows'), uint8([1,2,2,3,2,4]))
+%!assert(unique(uint8([1,2,2,3,2,4])), uint8([1,2,3,4]))
+%!assert(unique(uint8([1,2,2,3,2,4]'), 'rows'), uint8([1,2,3,4]'))
+%!test
+%! [a,i,j] = unique([1,1,2,3,3,3,4]);
+%! assert(a,[1,2,3,4])
+%! assert(i,[2,3,6,7])
+%! assert(j,[1,1,2,3,3,3,4])
+%!
+%!test
+%! [a,i,j] = unique([1,1,2,3,3,3,4]','first');
+%! assert(a,[1,2,3,4]')
+%! assert(i,[1,3,4,7]')
+%! assert(j,[1,1,2,3,3,3,4]')
+%!
+%!test
+%! [a,i,j] = unique({'z'; 'z'; 'z'});
+%! assert(a,{'z'})
+%! assert(i,[3]')
+%! assert(j,[1,1,1]')
+%!
+%!test
+%! A=[1,2,3;1,2,3];
+%! [a,i,j] = unique(A,'rows');
+%! assert(a,[1,2,3])
+%! assert(A(i,:),a)
+%! assert(a(j,:),A)
git://git.creatis.insa-lyon.fr / CreaPhase.git / blobdiff