update packages

[CreaPhase.git] / octave_packages / m / general / flipdim.m

diff --git a/octave_packages/m/general/flipdim.m b/octave_packages/m/general/flipdim.m
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+## Copyright (C) 2004-2012 David Bateman
+## Copyright (C) 2009 VZLU Prague
+##
+## 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} {} flipdim (@var{x})
+## @deftypefnx {Function File} {} flipdim (@var{x}, @var{dim})
+## Return a copy of @var{x} flipped about the dimension @var{dim}.
+## @var{dim} defaults to the first non-singleton dimension.
+## For example:
+##
+## @example
+## @group
+## flipdim ([1, 2; 3, 4], 2)
+##       @result{}  2  1
+##           4  3
+## @end group
+## @end example
+## @seealso{fliplr, flipud, rot90, rotdim}
+## @end deftypefn
+
+## Author: David Bateman, Jaroslav Hajek
+
+function y = flipdim (x, dim)
+
+  if (nargin != 1 && nargin != 2)
+    print_usage ();
+  endif
+
+  nd = ndims (x);
+  sz = size (x);
+  if (nargin == 1)
+    ## Find the first non-singleton dimension.
+    (dim = find (sz > 1, 1)) || (dim = 1);
+  elseif (! (isscalar (dim) && isindex (dim)))
+    error ("flipdim: DIM must be a positive integer");
+  endif
+
+  idx(1:max(nd, dim)) = {':'};
+  idx{dim} = size (x, dim):-1:1;
+  y = x(idx{:});
+
+endfunction
+
+%!error flipdim ();
+%!error flipdim (1, 2, 3);
+
+%!assert (flipdim ([1,2;3,4]), flipdim ([1,2 ; 3,4], 1));
+%!assert (flipdim ([1,2;3,4], 2), [2,1;4,3]);
+%!assert (flipdim ([1,2;3,4], 3), [1,2;3,4]);
+
+## FIXME -- we need tests for multidimensional arrays.