Mercurial > octave
view scripts/general/nextpow2.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 | 863730dd0f83 |
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######################################################################## ## ## Copyright (C) 1995-2022 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{n} =} nextpow2 (@var{x}) ## Compute the exponent for the smallest power of two larger than the input. ## ## For each element in the input array @var{x}, return the first integer ## @var{n} such that ## @tex ## $2^n \ge |x|$. ## @end tex ## @ifnottex ## 2^n @geq{} abs (x). ## @end ifnottex ## ## @seealso{pow2, log2} ## @end deftypefn function n = nextpow2 (x) if (nargin < 1) print_usage (); endif if (! isnumeric (x)) error ("nextpow2: X must be numeric"); endif [f, n] = log2 (abs (x)); idx = (n == 0); # Find any failures of log2 function (n == 0) n(idx) = f(idx); # and copy over value. n(f == 0.5)--; endfunction %!assert (nextpow2 (16), 4) %!assert (nextpow2 (17), 5) %!assert (nextpow2 (31), 5) %!assert (nextpow2 (-16), 4) %!assert (nextpow2 (-17), 5) %!assert (nextpow2 (-31), 5) %!assert (nextpow2 (1:17), [0 1 2 2 3 3 3 3 4 4 4 4 4 4 4 4 5]) ## Special cases %!assert (nextpow2 (0), 0) %!assert (nextpow2 (1), 0) %!assert (nextpow2 (Inf), Inf) %!assert (nextpow2 (-Inf), Inf) %!assert (nextpow2 (NaN), NaN) %!assert (nextpow2 ([1, Inf, 3, -Inf, 9, NaN]), [0, Inf, 2, Inf, 4, NaN]) ## Test input validation %!error <Invalid call> nextpow2 () %!error <X must be numeric> nextpow2 ("t")