Mercurial > octave
view scripts/general/circshift.m @ 20852:516bb87ea72e
2015 Code Sprint: remove class of function from docstring for all m-files.
author | Rik <rik@octave.org> |
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date | Sat, 12 Dec 2015 07:31:00 -0800 |
parents | 74cc8ae4e2b0 |
children | bac0d6f07a3e |
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## Copyright (C) 2004-2015 David Bateman ## ## 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 {} {@var{y} =} circshift (@var{x}, @var{n}) ## @deftypefnx {} {@var{y} =} circshift (@var{x}, @var{n}, @var{dim}) ## Circularly shift the values of the array @var{x}. ## ## @var{n} must be a vector of integers no longer than the number of dimensions ## in @var{x}. The values of @var{n} can be either positive or negative, which ## determines the direction in which the values of @var{x} are shifted. If an ## element of @var{n} is zero, then the corresponding dimension of @var{x} will ## not be shifted. ## ## If a scalar @var{dim} is given then operate along the specified dimension. ## In this case @var{n} must be a scalar as well. ## ## Examples: ## ## @example ## @group ## x = [1, 2, 3; 4, 5, 6; 7, 8, 9]; ## circshift (x, 1) ## @result{} 7, 8, 9 ## 1, 2, 3 ## 4, 5, 6 ## circshift (x, -2) ## @result{} 7, 8, 9 ## 1, 2, 3 ## 4, 5, 6 ## circshift (x, [0,1]) ## @result{} 3, 1, 2 ## 6, 4, 5 ## 9, 7, 8 ## @end group ## @end example ## @seealso{permute, ipermute, shiftdim} ## @end deftypefn function y = circshift (x, n, dim) if (nargin < 2 || nargin > 3) print_usage (); endif if (isempty (x)) y = x; return; endif if (nargin == 3) if (! isscalar (n)) error ("circshift: N must be a scalar when DIM is also specified"); endif n = [zeros(1, dim-1), n]; endif nd = ndims (x); sz = size (x); if (! isvector (n) || length (n) > nd) error ("circshift: N must be a vector, no longer than the number of dimensions in X"); elseif (any (n != fix (n))) error ("circshift: all values of N must be integers"); endif idx = repmat ({':'}, 1, nd); for i = 1:length (n); b = n(i); d = sz(i); if (b > 0) b = rem (b, d); idx{i} = [d-b+1:d, 1:d-b]; elseif (b < 0) b = rem (abs (b), d); idx{i} = [b+1:d, 1:b]; endif endfor y = x(idx{:}); endfunction %!shared x %! x = [1, 2, 3; 4, 5, 6; 7, 8, 9]; %!assert (circshift (x, 1), [7, 8, 9; 1, 2, 3; 4, 5, 6]) %!assert (circshift (x, -2), [7, 8, 9; 1, 2, 3; 4, 5, 6]) %!assert (circshift (x, [0, 1]), [3, 1, 2; 6, 4, 5; 9, 7, 8]) %!assert (circshift ([], 1), []) %!assert (circshift (eye (3), 1), circshift (eye (3), 1)) %!assert (circshift (eye (3), 1), [0,0,1;1,0,0;0,1,0]) %!assert (circshift (x, -2, 1), [7, 8, 9; 1, 2, 3; 4, 5, 6]) %!assert (circshift (x, 1, 2), [3, 1, 2; 6, 4, 5; 9, 7, 8]) ## Test input validation %!error circshift () %!error circshift (1) %!error circshift (1,2,3) %!error <N must be a scalar> circshift (1, [2 3], 4) %!error <N must be a vector> circshift (1, ones (2,2)) %!error <no longer than the number of dimensions in X> circshift (1, [1 2 3]) %!error <all values of N must be integers> circshift (1, 1.5)