Mercurial > octave
view scripts/geometry/roty.m @ 31546:c664627d601e
tsearchn.m: Use Octave coding conventions.
* tsearchn.m: Use function name in error() messages. Use "endif" rather than
bare "end". Capitalize function input parameters in error() messages to match
documentation. Cuddle parentheses to variable when performing indexing.
Use '!' for logical not operator. Use two newlines between end of function
and start of BIST tests. Add BIST tests for input validation.
author | Rik <rik@octave.org> |
---|---|
date | Fri, 25 Nov 2022 09:41:12 -0800 |
parents | 796f54d4ddbf |
children | 597f3ee61a48 |
line wrap: on
line source
######################################################################## ## ## Copyright (C) 2019-2022 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{T} =} roty (@var{angle}) ## ## @code{roty} returns the 3x3 transformation matrix corresponding to an active ## rotation of a vector about the y-axis by the specified @var{angle}, given in ## degrees, where a positive angle corresponds to a counterclockwise ## rotation when viewing the z-x plane from the positive y side. ## ## The form of the transformation matrix is: ## @tex ## $$ ## T = \left[\matrix{ \cos(angle) & 0 & \sin(angle) \cr ## 0 & 1 & 0 \cr ## -\sin(angle) & 0 & \cos(angle)}\right]. ## $$ ## @end tex ## @ifnottex ## ## @example ## @group ## | cos(@var{angle}) 0 sin(@var{angle}) | ## T = | 0 1 0 | ## | -sin(@var{angle}) 0 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 z-axis, rotated ## 90-degrees about the y-axis, will result in a vector pointing along the ## positive x-axis: ## ## @example ## @group ## >> u = [0 0 1]' ## u = ## 0 ## 0 ## 1 ## ## >> T = roty (90) ## T = ## 0.00000 0.00000 1.00000 ## 0.00000 1.00000 0.00000 ## -1.00000 0.00000 0.00000 ## ## >> v = T*u ## v = ## 1.00000 ## 0.00000 ## 0.00000 ## @end group ## @end example ## ## @seealso{rotx, rotz} ## @end deftypefn function T = roty (angle) if (nargin < 1 || ! isscalar (angle)) print_usage (); endif angle *= pi / 180; s = sin (angle); c = cos (angle); T = [c 0 s; 0 1 0; -s 0 c]; endfunction ## Function output tests %!assert (roty (0), [1 0 0; 0 1 0; 0 0 1]) %!assert (roty (45), [sqrt(2) 0 sqrt(2); 0 2 0; -sqrt(2) 0 sqrt(2)]./2, 1e-12) %!assert (roty (90), [0 0 1; 0 1 0; -1 0 0], 1e-12) %!assert (roty (180), [-1 0 0; 0 1 0; 0 0 -1], 1e-12) ## Test input validation %!error <Invalid call> roty () %!error <Invalid call> roty ([1 2 3])