Mercurial > octave
view scripts/elfun/sind.m @ 30249:bc22395f60fa
maint: merge stable to default.
author | John W. Eaton <jwe@octave.org> |
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date | Fri, 22 Oct 2021 12:05:59 -0400 |
parents | 7854d5752dd2 |
children | 9ed1cf9e446e 796f54d4ddbf |
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######################################################################## ## ## Copyright (C) 2006-2021 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 {} {} sind (@var{x}) ## Compute the sine for each element of @var{x} in degrees. ## ## The function is more accurate than @code{sin} for large values of @var{x} ## and for multiples of 180 degrees (@code{@var{x}/180} is an integer) where ## @code{sind} returns 0 rather than a small value on the order of eps. ## @seealso{asind, sin} ## @end deftypefn function y = sind (x) if (nargin < 1) print_usage (); endif if (! isnumeric (x)) error ("sind: X must be numeric"); endif x_iscomplex = iscomplex (x); if (x_iscomplex) xi = imag (x); endif x = real (x); ## Wrap multiples so that new domain is [-180, 180) x = mod (x-180, 360) - 180; if (x_iscomplex) y = sin (complex (x, xi) / 180 * pi); ## Integer multiples of pi must be exactly zero y(x == -180) = complex (0, imag (y(x == -180))); else y = sin (x / 180 * pi); ## Integer multiples of pi must be exactly zero y(x == -180) = 0; endif endfunction %!assert (sind (10:20:360), sin ([10:20:360] * pi/180), 5*eps) %!assert (sind ([-360, -180, 0, 180, 360]) == 0) %!assert (sind ([-270, -90, 90, 270]), [1, -1, 1, -1]) %!assert (sind ([-Inf, NaN, +Inf, 0]), [NaN, NaN, NaN, 0]) %!assert (sind (+23) == -sind (-23)) %!assert (sind (1e6), -0.984807753012208, 5*eps) %!assert (sind (180 + 180i), -i*sinh (pi)) %!assert (sind (1e6 + 180i), -11.415845458288851 + 2.0054175437381652i, 5*eps) %!error <Invalid call> sind () %!error <X must be numeric> sind ("abc")