Mercurial > octave
view scripts/general/shiftdim.m @ 30893:e1788b1a315f
maint: Use "fcn" as preferred abbreviation for "function" in m-files.
* accumarray.m, accumdim.m, quadl.m, quadv.m, randi.m, structfun.m,
__is_function__.m, uigetfile.m, uimenu.m, uiputfile.m, doc_cache_create.m,
colorspace_conversion_input_check.m, imageIO.m, argnames.m, vectorize.m,
vectorize.m, normest1.m, inputname.m, nthargout.m, display_info_file.m,
decic.m, ode15i.m, ode15s.m, ode23.m, ode23s.m, ode45.m, odeset.m,
check_default_input.m, integrate_adaptive.m, ode_event_handler.m,
runge_kutta_23.m, runge_kutta_23s.m, runge_kutta_45_dorpri.m,
runge_kutta_interpolate.m, starting_stepsize.m, __all_opts__.m, fminbnd.m,
fminsearch.m, fminunc.m, fsolve.m, fzero.m, sqp.m, fplot.m, plotyy.m,
__bar__.m, __ezplot__.m, flat_entry.html, profexport.m, movfun.m, bicg.m,
bicgstab.m, cgs.m, eigs.m, gmres.m, pcg.m, __alltohandles__.m, __sprand__.m,
qmr.m, tfqmr.m, dump_demos.m:
Replace "func", "fun", "fn" in documentation and variable names with "fcn".
author | Rik <rik@octave.org> |
---|---|
date | Mon, 04 Apr 2022 18:14:56 -0700 |
parents | 796f54d4ddbf |
children | 597f3ee61a48 |
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######################################################################## ## ## Copyright (C) 2004-2022 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{y} =} shiftdim (@var{x}, @var{n}) ## @deftypefnx {} {[@var{y}, @var{ns}] =} shiftdim (@var{x}) ## Shift the dimensions of @var{x} by @var{n}, where @var{n} must be ## an integer scalar. ## ## When @var{n} is positive, the dimensions of @var{x} are shifted to the left, ## with the leading dimensions circulated to the end. If @var{n} is negative, ## then the dimensions of @var{x} are shifted to the right, with @var{n} ## leading singleton dimensions added. ## ## Called with a single argument, @code{shiftdim}, removes the leading ## singleton dimensions, returning the number of dimensions removed in the ## second output argument @var{ns}. ## ## For example: ## ## @example ## @group ## x = ones (1, 2, 3); ## size (shiftdim (x, -1)) ## @result{} 1 1 2 3 ## size (shiftdim (x, 1)) ## @result{} 2 3 ## [b, ns] = shiftdim (x) ## @result{} b = ## 1 1 1 ## 1 1 1 ## @result{} ns = 1 ## @end group ## @end example ## @seealso{reshape, permute, ipermute, circshift, squeeze} ## @end deftypefn function [y, ns] = shiftdim (x, n) if (nargin < 1) print_usage (); endif nd = ndims (x); orig_dims = size (x); if (nargin == 1) ## Find the first non-singleton dimension. (n = find (orig_dims != 1, 1) - 1) || (n = nd); elseif (! (isscalar (n) && n == fix (n))) error ("shiftdim: N must be a scalar integer"); endif if (n >= nd) n = rem (n, nd); endif if (n < 0) singleton_dims = ones (1, -n); y = reshape (x, [singleton_dims, orig_dims]); elseif (n > 0) ## We need permute here instead of reshape to shift values in a ## compatible way. y = permute (x, [n+1:nd 1:n]); else y = x; endif ns = n; endfunction %!test %! x = rand (1, 1, 4, 2); %! [y, ns] = shiftdim (x); %! assert (size (y), [4 2]); %! assert (ns, 2); %! assert (shiftdim (y, -2), x); %! assert (size (shiftdim (x, 2)), [4 2]); %!assert (size (shiftdim (rand (0, 1, 2))), [0 1 2]) ## Test input validation %!error <Invalid call> shiftdim () %!error shiftdim (1, ones (2)) %!error shiftdim (1, 1.5)