update packages

[CreaPhase.git] / octave_packages / m / set / setdiff.m

diff --git a/octave_packages/m/set/setdiff.m b/octave_packages/m/set/setdiff.m
new file mode 100644 (file)
index 0000000..3b0ff36
--- /dev/null
+++ b/octave_packages/m/set/setdiff.m
@@ -0,0 +1,105 @@
+## 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} {} setdiff (@var{a}, @var{b})
+## @deftypefnx {Function File} {} setdiff (@var{a}, @var{b}, "rows")
+## @deftypefnx {Function File} {[@var{c}, @var{i}] =} setdiff (@var{a}, @var{b})
+## Return the elements in @var{a} that are not in @var{b}, sorted in
+## ascending order.  If @var{a} and @var{b} are both column vectors
+## return a column vector, otherwise return a row vector.
+## @var{a}, @var{b} may be cell arrays of string(s).
+##
+## Given the optional third argument @samp{"rows"}, return the rows in
+## @var{a} that are not in @var{b}, sorted in ascending order by rows.
+##
+## If requested, return @var{i} such that @code{c = a(i)}.
+## @seealso{unique, union, intersect, setxor, ismember}
+## @end deftypefn
+
+## Author: Paul Kienzle
+## Adapted-by: jwe
+
+function [c, i] = setdiff (a, b, varargin)
+
+  if (nargin < 2 || nargin > 3)
+    print_usage ();
+  endif
+
+  [a, b] = validargs ("setdiff", a, b, varargin{:});
+
+  if (nargin > 2)
+    if (nargout > 1)
+      [c, i] = unique (a, "rows");
+    else
+      c = unique (a, "rows");
+    endif
+    if (! isempty (c) && ! isempty (b))
+      ## Form a and b into combined set.
+      b = unique (b, "rows");
+      [dummy, idx] = sortrows ([c; b]);
+      ## Eliminate those elements of a that are the same as in b.
+      dups = find (all (dummy(1:end-1,:) == dummy(2:end,:), 2));
+      c(idx(dups),:) = [];
+      if (nargout > 1)
+        i(idx(dups),:) = [];
+      endif
+    endif
+  else
+    if (nargout > 1)
+      [c, i] = unique (a);
+    else
+      c = unique (a);
+    endif
+    if (! isempty (c) && ! isempty (b))
+      ## Form a and b into combined set.
+      b = unique (b);
+      [dummy, idx] = sort ([c(:); b(:)]);
+      ## Eliminate those elements of a that are the same as in b.
+      if (iscellstr (dummy))
+        dups = find (strcmp (dummy(1:end-1), dummy(2:end)));
+      else
+        dups = find (dummy(1:end-1) == dummy(2:end));
+      endif
+      c(idx(dups)) = [];
+      if (nargout > 1)
+        i(idx(dups)) = [];
+      endif
+      ## Reshape if necessary.
+      if (size (c, 1) != 1 && size (b, 1) == 1)
+        c = c.';
+      endif
+    endif
+  endif
+
+endfunction
+
+%!assert(setdiff(["bb";"zz";"bb";"zz"],["bb";"cc";"bb"],"rows"), "zz")
+%!assert(setdiff(["b";"z";"b";"z"],["b";"c";"b"],"rows"), "z")
+%!assert(setdiff(["b";"z";"b";"z"],["b";"c";"b"]), "z")
+%!assert(setdiff([1, 1; 2, 2; 3, 3; 4, 4], [1, 1; 2, 2; 4, 4], "rows"), [3 3])
+%!assert(setdiff([1; 2; 3; 4], [1; 2; 4], "rows"), 3)
+%!assert(setdiff([1, 2; 3, 4], [1, 2; 3, 6], "rows"), [3, 4])
+%!assert(setdiff({"one","two";"three","four"},{"one","two";"three","six"}), {"four"})
+
+%!test
+%! a = [3, 1, 4, 1, 5]; b = [1, 2, 3, 4];
+%! [y, i] = setdiff (a, b.');
+%! assert(y, [5]);
+%! assert(y, a(i));