Mercurial > hg > octave-nkf
diff scripts/set/union.m @ 7344:4571f691b0ce
[project @ 2008-01-04 18:18:22 by jwe]
author | jwe |
---|---|
date | Fri, 04 Jan 2008 18:18:22 +0000 |
parents | a1dbe9d80eee |
children | 83a8781b529d 746f13936eee |
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--- a/scripts/set/union.m +++ b/scripts/set/union.m @@ -1,5 +1,5 @@ ## Copyright (C) 1994, 1996, 1997, 1999, 2000, 2003, 2004, 2005, 2006, -## 2007 John W. Eaton +## 2007, 2008 John W. Eaton ## ## This file is part of Octave. ## @@ -19,13 +19,26 @@ ## -*- texinfo -*- ## @deftypefn {Function File} {} union (@var{x}, @var{y}) +## @deftypefnx{Function File} {} union (@var{x}, @var{y}, "rows") ## Return the set of elements that are in either of the sets @var{x} and ## @var{y}. For example, ## ## @example ## @group -## union ([ 1, 2, 4 ], [ 2, 3, 5 ]) -## @result{} [ 1, 2, 3, 4, 5 ] +## union ([1, 2, 4], [2, 3, 5]) +## @result{} [1, 2, 3, 4, 5] +## @end group +## @end example +## +## If the optional third input argument is the string "rows" each row of +## the matrices @var{x} and @var{y} will be considered an element of sets. +## For example, +## @example +## @group +## union([1, 2; 2, 3], [1, 2; 3, 4], "rows") +## @result{} 1 2 +## 2 3 +## 3 4 ## @end group ## @end example ## @seealso{create_set, intersection, complement} @@ -33,23 +46,31 @@ ## Author: jwe -function y = union(a,b) +function y = union (a, b, varargin) - if (nargin != 2) + if (nargin < 2 || nargin > 3) print_usage (); endif + if (nargin == 3 && ! strcmpi (varargin{1}, "rows")) + error ("union: if a third input argument is present, it must be the string 'rows'"); + endif + if (isempty (a)) - y = create_set (b); + y = create_set (b, varargin{:}); elseif (isempty (b)) - y = create_set (a); - else + y = create_set (a, varargin{:}); + elseif (nargin == 2) y = create_set ([a(:); b(:)]); if (size (a, 1) == 1 || size (b, 1) == 1) y = y(:).'; else y = y(:); endif + elseif (ndims (a) == 2 && ndims (b) == 2 && columns (a) == columns (b)) + y = create_set ([a; b], "rows"); + else + error ("union: input arguments must contain the same number of columns when \"rows\" is specified"); endif endfunction