Mercurial > octave
view scripts/general/flip.m @ 33567:9f0f7a898b73 bytecode-interpreter tip
maint: Merge default to bytecode-interpreter
author | Arun Giridhar <arungiridhar@gmail.com> |
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date | Fri, 10 May 2024 17:57:29 -0400 |
parents | 2e484f9f1f18 |
children |
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######################################################################## ## ## Copyright (C) 2004-2024 The Octave Project Developers ## ## See the file COPYRIGHT.md in the top-level directory of this ## distribution or <https://octave.org/copyright/>. ## ## 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 ## <https://www.gnu.org/licenses/>. ## ######################################################################## ## -*- texinfo -*- ## @deftypefn {} {@var{B} =} flip (@var{A}) ## @deftypefnx {} {@var{B} =} flip (@var{A}, @var{dim}) ## Return a copy of array @var{A} flipped across dimension @var{dim}. ## ## If @var{dim} is unspecified it defaults to the first non-singleton ## dimension. ## ## Examples: ## ## @example ## ## row vector ## flip ([1 2 3 4]) ## @result{} 4 3 2 1 ## ## ## column vector ## flip ([1; 2; 3; 4]) ## @result{} 4 ## 3 ## 2 ## 1 ## ## ## 2-D matrix along dimension 1 ## flip ([1 2; 3 4]) ## @result{} 3 4 ## 1 2 ## ## ## 2-D matrix along dimension 2 ## flip ([1 2; 3 4], 2) ## @result{} 2 1 ## 4 3 ## @end example ## ## @seealso{fliplr, flipud, rot90, rotdim, permute, transpose} ## @end deftypefn function B = flip (A, dim) if (nargin < 1) print_usage (); endif nd = ndims (A); sz = size (A); if (nargin == 1) ## Find the first non-singleton dimension. (dim = find (sz > 1, 1)) || (dim = 1); elseif (! (isscalar (dim) && isindex (dim))) error ("flip: DIM must be a positive integer"); endif idx(1:max(nd, dim)) = {':'}; idx{dim} = size (A, dim):-1:1; B = A(idx{:}); endfunction %!assert (flip ([1 2; 3 4], 2), [2 1; 4 3]) %!assert (flip ([1 2; 3 4], 3), [1 2; 3 4]) ## Test defaults %!assert (flip ([1 2 3 4]), [4 3 2 1]) %!assert (flip ([1 2 3 4].'), [4 3 2 1].') %!assert (flip ([1 2; 3 4]), flip ([1 2 ; 3 4], 1)) ## Test NDArrays %!test %! a(1:2,1:2,1) = [1 2; 3 4]; %! a(1:2,1:2,2) = [5 6; 7 8]; %! b(1:2,1:2,1) = [5 6; 7 8]; %! b(1:2,1:2,2) = [1 2; 3 4]; %! assert (flip (a, 3), b); %!test %! a = b = zeros (2, 2, 1, 2); %! a(1:2,1:2,:,1) = [1 2; 3 4]; %! a(1:2,1:2,:,2) = [5 6; 7 8]; %! b(1:2,1:2,:,1) = [5 6; 7 8]; %! b(1:2,1:2,:,2) = [1 2; 3 4]; %! assert (flip (a, 3), a); %! assert (flip (a, 4), b); %! assert (flip (a, 5), a); %!error <Invalid call> flip () %!error <DIM must be a positive integer> flip (magic (3), -1)