Mercurial > octave
view scripts/geometry/rotx.m @ 32078:632f9b828de1
Avoid using file_stat in liboctave/util (bug #59711).
* cmd-edit.cc (looks_like_filename), cmd-hist.cc (gnu_history::do_append),
kpse.cc (kpse_element_dir), oct-glob.cc (glob, windows_glob),
url-transfer.cc (base_url_transfer::mget_directory): Use functions "dir_exists"
or "file_exists" instead of "file_stat".
* kpse.cc (dir_p), oct-glob.cc (single_match_exists): Remove unused static
functions.
author | Markus Mützel <markus.muetzel@gmx.de> |
---|---|
date | Sat, 06 May 2023 10:56:33 +0200 |
parents | 597f3ee61a48 |
children | 2e484f9f1f18 |
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######################################################################## ## ## Copyright (C) 2019-2023 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{T} =} rotx (@var{angle}) ## ## @code{rotx} returns the 3x3 transformation matrix corresponding to an active ## rotation of a vector about the x-axis by the specified @var{angle}, given in ## degrees, where a positive angle corresponds to a counterclockwise ## rotation when viewing the y-z plane from the positive x side. ## ## The form of the transformation matrix is: ## @tex ## $$ ## T = \left[\matrix{ 1 & 0 & 0 \cr ## 0 & \cos(angle) & -\sin(angle)\cr ## 0 & \sin(angle) & \cos(angle)}\right]. ## $$ ## @end tex ## @ifnottex ## ## @example ## @group ## | 1 0 0 | ## T = | 0 cos(@var{angle}) -sin(@var{angle}) | ## | 0 sin(@var{angle}) cos(@var{angle}) | ## @end group ## @end example ## @end ifnottex ## ## This rotation matrix is intended to be used as a left-multiplying matrix ## when acting on a column vector, using the notation ## @code{@var{v} = @var{T}*@var{u}}. ## For example, a vector, @var{u}, pointing along the positive y-axis, rotated ## 90-degrees about the x-axis, will result in a vector pointing along the ## positive z-axis: ## ## @example ## @group ## >> u = [0 1 0]' ## u = ## 0 ## 1 ## 0 ## ## >> T = rotx (90) ## T = ## 1.00000 0.00000 0.00000 ## 0.00000 0.00000 -1.00000 ## 0.00000 1.00000 0.00000 ## ## >> v = T*u ## v = ## 0.00000 ## 0.00000 ## 1.00000 ## @end group ## @end example ## ## @seealso{roty, rotz} ## @end deftypefn function T = rotx (angle) if (nargin < 1 || ! isscalar (angle)) print_usage (); endif angle *= pi / 180; s = sin (angle); c = cos (angle); T = [1 0 0; 0 c -s; 0 s c]; endfunction ## Function output tests %!assert (rotx (0), [1 0 0; 0 1 0; 0 0 1]) %!assert (rotx (45), [1, 0, 0; [0; 0],[(sqrt(2)/2).*[1 -1; 1 1]]], 1e-12) %!assert (rotx (90), [1 0 0; 0 0 -1; 0 1 0], 1e-12) %!assert (rotx (180), [1 0 0; 0 -1 0; 0 0 -1], 1e-12) ## Test input validation %!error <Invalid call> rotx () %!error <Invalid call> rotx ([1 2 3])