1 ## Copyright (C) 2010 Lukas F. Reichlin
3 ## This program is free software: you can redistribute it and/or modify
4 ## it under the terms of the GNU General Public License as published by
5 ## the Free Software Foundation, either version 3 of the License, or
6 ## (at your option) any later version.
8 ## This program is distributed in the hope that it will be useful,
9 ## but WITHOUT ANY WARRANTY; without even the implied warranty of
10 ## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 ## GNU General Public License for more details.
13 ## You should have received a copy of the GNU General Public License
14 ## along with this program. If not, see <http://www.gnu.org/licenses/>.
17 ## Element-wise multiplication of two quaternions. Used by Octave for "q1 .* q2".
19 ## Author: Lukas Reichlin <lukas.reichlin@gmail.com>
23 function a = times (a, b)
25 if (! isa (a, "quaternion"))
29 if (! isa (b, "quaternion"))
33 w = a.w .* b.w - a.x .* b.x - a.y .* b.y - a.z .* b.z;
34 x = a.y .* b.z - a.z .* b.y + a.w .* b.x + a.x .* b.w;
35 y = a.z .* b.x - a.x .* b.z + a.w .* b.y + a.y .* b.w;
36 z = a.x .* b.y - a.y .* b.x + a.w .* b.z + a.z .* b.w;